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anatomy, anatomy and physiology, anomaly, comparative anatomy, thermal
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Elephant
Bibliographic
Database
www.elephantcare.org
References
updated October 2009 by date of publication, most recent first.
Gheerbrant,
E., 2009. Paleocene emergence of elephant relatives and the rapid
radiation of African ungulates
43. Proc. Natl. Acad. Sci. U. S. A 106, 10717-10721.
Abstract: Elephants are the only living representatives of the
Proboscidea, a formerly diverse mammalian order whose history began with
the 55-million years (mys) old Phosphatherium. Reported here is the
discovery from the early late Paleocene of Morocco, ca. 60 mys, of the
oldest and most primitive elephant relative, Eritherium azzouzorum n.g.,
n.sp., which is one of the earliest known representatives of modern
placental orders. This well supported stem proboscidean is
extraordinarily primitive and condylarth-like. It provides the first
dental evidence of a resemblance between the proboscideans and African
ungulates (paenungulates) on the one hand and the louisinines and early
macroscelideans on the other. Eritherium illustrates the origin of the
elephant order at a previously unknown primitive stage among
paenungulates and "ungulates." The primitive morphology of Eritherium
suggests a recent and rapid paenungulate radiation after the
Cretaceous-Tertiary boundary, probably favoured by early endemic African
paleoecosystems. At a broader scale, Eritherium provides a new old
calibration point of the placental tree and supports an explosive
placental radiation. The Ouled Abdoun basin, which yields the oldest
known African placentals, is a key locality for elucidating phylogeny
and early evolution of paenungulates and other related endemic African
lineages
Hakeem, A.Y.,
Sherwood, C.C., Bonar, C.J., Butti, C., Hof, P.R., Allman, J.M., 2009.
Von Economo neurons in the elephant brain. Anat. Rec. (Hoboken. ) 292,
242-248.
Abstract: Von Economo neurons (VENs), previously found in humans, all of
the great ape species, and four cetacean species, are also present in
African and Indian elephants. The VENs in the elephant are primarily
found in similar locations to those in the other species. They are most
abundant in the frontoinsular cortex (area FI) and are also present at
lower density in the anterior cingulate cortex. Additionally, they are
found in a dorsolateral prefrontal area and less abundantly in the
region of the frontal pole. The VEN morphology appears to have arisen
independently in hominids, cetaceans, and elephants, and may reflect a
specialization for the rapid transmission of crucial social information
in very large brains
Jantou, V.,
Turmaine, M., West, G.D., Horton, M.A., McComb, D.W., 2009. Focused ion
beam milling and ultramicrotomy of mineralised ivory dentine for
analytical transmission electron microscopy
114. Micron. 40, 495-501.
Abstract: The use of focused ion beam (FIB) milling for preparation of
sections of mineralised ivory dentine for transmission electron
microscopy (TEM) is investigated. Ivory dentine is essentially composed
of fibrillar type-I collagen and apatite crystals. The aim of this
project is to gain a clearer understanding of the relationship between
the organic and inorganic components of ivory dentine using analytical
TEM, in order to utilise these analytical techniques in the context of
common skeletal diseases such as osteoporosis and arthritis. TEM
sections were prepared in both single and dual beam FIB instruments,
using two standard lift-out techniques, in situ and ex situ. The FIB
sections were systematically compared with sections prepared by
ultramicrotomy, the traditional preparation route in biological systems,
in terms of structural and chemical differences. A clear advantage of
FIB milling over ultramicrotomy is that dehydration, embedding and
section flotation can be eliminated, so that partial mineral loss due to
dissolution is avoided. The characteristic banding of collagen fibrils
was clearly seen in FIB milled sections without the need for any
chemical staining, as is commonly employed in ultramicrotomy. The FIB
milling technique was able to produce high-quality TEM sections of ivory
dentine, which are suitable for further investigation using electron
energy-loss spectroscopy (EELS) and energy-filtering TEM (EFTEM) to
probe the collagen/apatite interface
Lozi, H.,
Goodwin, T.E., Rasmussen, L.E.L., Whitehouse, A.M., Schulte, B.A., 2009. Sexual dimorphism in the
performance of chemosensory investigatory behaviours by African
elephants (Loxodonta africana).
Behaviour 146, 373-392.
Abstract:
Sexual dimorphism in morphology can be accompanied by behavioural
differences between the sexes. We examined if investigatory behaviour
involving the trunk of African elephants showed sexual dimorphism. Males
compete and search for females, but they have a lengthy period of
development before they are socially viable mates. Receptive females are
relatively rare. We hypothesized that males would display higher rates
of chemosensory behaviour following puberty than females. Because males
disperse, they were hypothesized to be more likely to contact elephants
outside their kinship group. We observed the trunk tip, chemosensory
behaviours of African elephants at Addo Elephant National Park, South
Africa. For 208 elephants, we found no significant differences in state
behaviours around waterholes by age or sex. Yet, older elephants were
more likely to investigate the environment and elephant excrement than
younger animals. Males were more likely to investigate urine and faeces
than females. Only post-puberty animals contacted non-family with males
investigating both sexes, while investigations by and to females only
involved post-puberty males. Overall, the probability of performing
chemosensory behaviours depended on age and sex. Male elephants appear
more reliant than females on signals in urine and faeces with ensuing
inspections of individuals through trunk tip contacts.
Manger, P.R.,
Pillay, P., Maseko, B.C., Bhagwandin, A., Gravett, N., Moon, D.J.,
Jillani, N., Hemingway, J., 2009. Acquisition of brains from the African
elephant (Loxodonta africana): perfusion-fixation and dissection
113. J. Neurosci. Methods 179, 16-21.
Abstract: The current correspondence describes the in situ
perfusion-fixation of the brain of the African elephant. Due to both the
large size of proboscidean brains and the complex behaviour of these
species, the acquisition of good quality material for comparative
neuroanatomical analysis from these species is important. Three male
African elephants (20-30 years) that were to be culled as part of a
larger population management strategy were used. The animals were
humanely euthanized and the head removed from the body. Large tubes were
inserted into to the carotid arteries and the cranial vasculature
flushed with a rapid (20 min) rinse of 100 l of cold saline (4 degrees
C). Following the rinse the head was perfusion-fixed with a slower rinse
(40 min) of 100 l of cold (4 degrees C) 4% paraformaldehyde in 0.1M
phosphate buffer. This procedure resulted in well-fixed neural and other
tissue. After perfusion the brains were removed from the skull with the
aid of power tools, a procedure taking between 2 and 6h. The brains were
immediately post-fixed in the same solution for 72 h at 4 degrees C. The
brains were subsequently placed in a sucrose solution and finally an
antifreeze solution and are stored in a -20 degrees C freezer. The
acquisition of high quality neural material from African elephants that
can be used for immunohistochemistry and electron microscopy is of
importance in understanding the "hardware" underlying the behaviour of
this species. This technique can be used on a variety of large mammals
to obtain high quality material for comparative neuroanatomical studies
Murata, Y.,
Yonezawa, T., Kihara, I., Kashiwamura, T., Sugihara, Y., Nikaido, M.,
Okada, N., Endo, H., Hasegawa, M., 2009. Chronology of the extant
African elephant species and case study of the species identification of
the small African elephant with the molecular phylogenetic method
70. Gene 441, 176-186.
Abstract: Despite vigorous genetic studies of African elephants
(Loxodonta africana and L. cyclotis) during the last decade, their
evolutionary history is still obscure. Phylogenetic studies and
coalescence time estimation using longer nucleotide sequence data from
denser samplings are necessary to better understand the natural history
of African elephants. Further, species identification among African
elephants is sometimes very difficult using only the external
morphological characteristics. This is a serious problem for making an
adequate breeding plan in zoological gardens. In this paper, we
investigated the continent-wide phylogeographical pattern of the African
elephants and estimated the coalescence times among them. From these
molecular data and geological evidence, we proposed an evolutionary
scenario for the African elephants. We further demonstrated the
effectiveness of molecular phylogenetic methods in species
identification.
Paul, G.,
2009. The nearly columnar limbs of elephants are very different from the
more flexed, spring action limbs of running mammals and birds. J. Exp.
Biol. 212, 152-3, author.
Saragusty, J., Hildebrandt, T.B., Behr, B., Knieriem, A., Kruse, J.,
Hermes, R., 2009.
Successful
cryopreservation of Asian elephant (Elephas maximus) spermatozoa. Anim
Reprod. Sci. 115, 255-266.
Abstract: Reproduction in captive elephants is low and infant mortality
is high, collectively leading to possible population extinction.
Artificial insemination was developed a decade ago; however, it relies
on fresh-chilled semen from just a handful of bulls with inconsistent
sperm quality. Artificial insemination with frozen-thawed sperm has
never been described, probably, in part, due to low semen quality after
cryopreservation. The present study was designed with the aim of finding
a reliable semen freezing protocol. Screening tests included freezing
semen with varying concentrations of ethylene glycol, propylene glycol,
trehalose, dimethyl sulfoxide and glycerol as cryoprotectants and
assessing cushioned centrifugation, rapid chilling to suprazero
temperatures, freezing extender osmolarity, egg yolk concentration,
post-thaw dilution with cryoprotectant-free BC solution and the addition
of 10% (v/v) of autologous seminal plasma. The resulting optimal
freezing protocol uses cushioned centrifugation, two-step dilution with
isothermal 285 m Osm/kg Berliner Cryomedium (BC) with final glycerol
concentration of 7% and 16% egg yolk, and freezing in large volume by
the directional freezing technique. After thawing, samples are diluted
1:1 with BC solution. Using this protocol, post-thaw evaluations results
were: motility upon thawing: 57.2+/-5.4%, motility following 30 min
incubation at 37 degrees C: 58.5+/-6.0% and following 3h incubation:
21.7+/-7.6%, intact acrosome: 57.1+/-5.2%, normal morphology:
52.0+/-5.8% and viability: 67.3+/-6.1%. With this protocol, good quality
semen can be accumulated for future use in artificial inseminations when
and where needed
Sherwood,
C.C., Stimpson, C.D., Butti, C., Bonar, C.J., Newton, A.L., Allman, J.M.,
Hof, P.R., 2009. Neocortical neuron types in Xenarthra and Afrotheria:
implications for brain evolution in mammals. Brain Struct. Funct. 213,
301-328.
Abstract: Interpreting the evolution of neuronal types in the cerebral
cortex of mammals requires information from a diversity of species.
However, there is currently a paucity of data from the Xenarthra and
Afrotheria, two major phylogenetic groups that diverged close to the
base of the eutherian mammal adaptive radiation. In this study, we used
immunohistochemistry to examine the distribution and morphology of
neocortical neurons stained for nonphosphorylated neurofilament protein,
calbindin, calretinin, parvalbumin, and neuropeptide Y in three
xenarthran species-the giant anteater (Myrmecophaga tridactyla), the
lesser anteater (Tamandua tetradactyla), and the two-toed sloth (Choloepus
didactylus)-and two afrotherian species-the rock hyrax (Procavia
capensis) and the black and rufous giant elephant shrew (Rhynchocyon
petersi). We also studied the distribution and morphology of astrocytes
using glial fibrillary acidic protein as a marker. In all of these
species, nonphosphorylated neurofilament protein-immunoreactive neurons
predominated in layer V. These neurons exhibited diverse morphologies
with regional variation. Specifically, high proportions of atypical
neurofilament-enriched neuron classes were observed, including
extraverted neurons, inverted pyramidal neurons, fusiform neurons, and
other multipolar types. In addition, many projection neurons in layers
II-III were found to contain calbindin. Among interneurons, parvalbumin-
and calbindin-expressing cells were generally denser compared to
calretinin-immunoreactive cells. We traced the evolution of certain
cortical architectural traits using phylogenetic analysis. Based on our
reconstruction of character evolution, we found that the living
xenarthrans and afrotherians show many similarities to the stem
eutherian mammal, whereas other eutherian lineages display a greater
number of derived traits
Soltis, J.,
2009. Vocal communication in African Elephants (Loxodonta africana)
61. Zoo. Biol. 28, 1-18.
Abstract: Research on vocal communication in African elephants has
increased in recent years, both in the wild and in captivity, providing
an opportunity to present a comprehensive review of research related to
their vocal behavior. Current data indicate that the vocal repertoire
consists of perhaps nine acoustically distinct call types, "rumbles"
being the most common and acoustically variable. Large vocal production
anatomy is responsible for the low-frequency nature of rumbles, with
fundamental frequencies in the infrasonic range. Additionally, resonant
frequencies of rumbles implicate the trunk in addition to the oral
cavity in shaping the acoustic structure of rumbles. Long-distance
communication is thought possible because low-frequency sounds propagate
more faithfully than high-frequency sounds, and elephants respond to
rumbles at distances of up to 2.5 km. Elephant ear anatomy appears
designed for detecting low frequencies, and experiments demonstrate that
elephants can detect infrasonic tones and discriminate small frequency
differences. Two vocal communication functions in the African elephant
now have reasonable empirical support. First, closely bonded but
spatially separated females engage in rumble exchanges, or "contact
calls," that function to coordinate movement or reunite animals. Second,
both males and females produce "mate attraction" rumbles that may
advertise reproductive states to the opposite sex. Additionally, there
is evidence that the structural variation in rumbles reflects the
individual identity, reproductive state, and emotional state of callers.
Growth in knowledge about the communication system of the African
elephant has occurred from a rich combination of research on wild
elephants in national parks and captive elephants in zoological parks.
Zoo Biol 28:1-18, 2009. (c) 2009 Wiley-Liss, Inc
Trimble, M.J.,
Ferreira, S.M., van Aarde, R.J., 2009.
Drivers of megaherbivore demographic fluctuations: inference from
elephants.
Journal of Zoology 1-9.
Abstract:
Environmentally induced variation in survival and fecundity generates
demographic fluctuations that affect population growth rate. However, a
general pattern of the comparative influence of variation in fecundity
and juvenile survival on elephant population dynamics has not been
investigated at a broad scale. We evaluated the relative importance of
conception, gestation, first year survival and subsequent survivorship
for controlling demographic variation by exploring the relationship
between past environmental conditions determined by integrated
normalized difference vegetation index (INDVI) and the shape of age
distributions at 17 sites across Africa. We showed that, generally,
INDVI during gestation best explained anomalies in age structure.
However, in areas with low mean annual rainfall, INDVI during the first
year of life was critical. The results challenge Eberhardt's paradigm
for population analysis that suggests that populations respond to
limited resource availability through a sequential decrease in juvenile
survival, reproductive rate and adult survival. Contrastingly, elephants
appear to respond first through a reduction in reproductive rate. We
conclude that this discrepancy is likely due to the evolutionary
significance of extremely large body size - an adaptation that increases
survival rate but decreases reproductive potential. Other megaherbivores
may respond similarly to resource limitation due to similarities in
population dynamics. Knowing how vital rates vary with changing
environmental conditions will permit better forecasts of the
trajectories of megaherbivore populations.
Asher, R.J.,
Lehmann, T., 2008. Dental eruption in afrotherian mammals. BMC. Biol. 6,
14.
Abstract: BACKGROUND: Afrotheria comprises a newly recognized clade of
mammals with strong molecular evidence for its monophyly. In contrast,
morphological data uniting its diverse constituents, including
elephants, sea cows, hyraxes, aardvarks, sengis, tenrecs and golden
moles, have been difficult to identify. Here, we suggest relatively late
eruption of the permanent dentition as a shared characteristic of
afrotherian mammals. This characteristic and other features (such as
vertebral anomalies and testicondy) recall the phenotype of a human
genetic pathology (cleidocranial dysplasia), correlations with which
have not been explored previously in the context of character evolution
within the recently established phylogeny of living mammalian clades.
RESULTS: Although data on the absolute timing of eruption in sengis,
golden moles and tenrecs are still unknown, craniometric comparisons for
ontogenetic series of these taxa show that considerable skull growth
takes place prior to the complete eruption of the permanent cheek teeth.
Specimens showing less than half (sengis, golden moles) or two-thirds (tenrecs,
hyraxes) of their permanent cheek teeth reach or exceed the median jaw
length of conspecifics with a complete dentition. With few exceptions,
afrotherians are closer to median adult jaw length with fewer erupted,
permanent cheek teeth than comparable stages of non-afrotherians.
Manatees (but not dugongs), elephants and hyraxes with known age data
show eruption of permanent teeth late in ontogeny relative to other
mammals. While the occurrence of delayed eruption, vertebral anomalies
and other potential afrotherian synapomorphies resemble some symptoms of
a human genetic pathology, these characteristics do not appear to covary
significantly among mammalian clades. CONCLUSION: Morphological
characteristics shared by such physically disparate animals such as
elephants and golden moles are not easy to recognize, but are now known
to include late eruption of permanent teeth, in addition to vertebral
anomalies, testicondy and other features. Awareness of their possible
genetic correlates promises insight into the developmental basis of
shared morphological features of afrotherians and other vertebrates
Carter, A.M.,
Miglino, M.A., Ambrosio, C.E., Santos, T.C., Rosas, F.C., Neto, J.A.,
Lazzarini, S.M., Carvalho, A.F., da Silva, V.M., 2008. Placentation in
the Amazonian manatee (Trichechus inunguis). Reprod. Fertil. Dev. 20,
537-545.
Abstract: Evidence from several sources supports a close phylogenetic
relationship between elephants and sirenians. To explore whether this
was reflected in similar placentation, we examined eight delivered
placentae from the Amazonian manatee using light microscopy and
immunohistochemistry. In addition, the fetal placental circulation was
described by scanning electron microscopy of vessel casts. The manatee
placenta was zonary and endotheliochorial, like that of the elephant.
The interhaemal barrier comprised maternal endothelium, cytotrophoblasts
and fetal endothelium. We found columnar trophoblast beneath the
chorionic plate and lining lacunae in this region, but there was no
trace in the term placenta of haemophagous activity. The gross anatomy
of the cord and fetal membranes was consistent with previous
descriptions and included a four-chambered allantoic sac, as also found
in the elephant and other afrotherians. Connective tissue septae
descended from the chorionic plate and carried blood vessels to the
labyrinth, where they gave rise to a dense capillary network. This
appeared to drain into shorter vessels near the chorionic plate. The
maternal vasculature could not be examined in the same detail, but
maternal capillaries ran rather straight and roughly parallel to the
fetal ones. Overall, there is a close resemblance in placentation
between the manatee and the elephant
Drews, B.,
Hermes, R., Goritz, F., Gray, C., Kurz, J., Lueders, I., Hildebrandt,
T.B., 2008. Early embryo development in the elephant assessed by serial
ultrasound examinations. Theriogenology 69, 1120-1128.
Abstract: The elephant has an extraordinary long pregnancy, lasting 21
months. However, knowledge on embryo development is limited. To date,
only single morphological observations of elephant embryo development
associated with placentation are available, all lacking correlation to
gestational age. The present study describes morphological
characteristics of early embryo development in the elephant with exact
biometric staging. Six pregnancies in five Asian and one African
elephants with known conception dates were followed by 2D and 3D
ultrasound, covering the embryonic period from ovulation to day 116
post-ovulation. The embryonic vesicle was earliest observed was on day
50 p.o. The proper embryo was not detected until day 62 p.o. Embryonic
heartbeat was first observed on day 71 p.o. The allantois, which became
visible as a single sacculation on day 71 p.o. was subdivided in four
compartments on day 76 p.o. By day 95 p.o., head, rump, front and hind
legs were clearly distinguished. Between days 95 and 103 p.o. the
choriovitelline placenta was replaced by the chorioallantoic placenta. A
physiological midgut herniation was transiently present between days 95
and 116 p.o. On the basis of the late appearance of the embryonic
vesicle, delayed implantation in the elephant is discussed. The study
provides a coherent description of elephant embryonic development,
formation of the extraembryonic organs and their role in placenta
formation, all of which are of interest for both comparative
evolutionary studies and the improvement of assisted reproduction
techniques
Hermes, R.,
Saragusty, J., Schaftenaar, W., Goritz, F., Schmitt, D.L., Hildebrandt,
T.B., 2008. Obstetrics in elephants. Theriogenology 70, 131-144.
Abstract: Obstetrics, one of the oldest fields in veterinary medicine,
is well described and practiced in domestic and exotic animals. However,
when providing care during elephant birth or dystocia, veterinary
intervention options differ greatly from any domestic species, and are
far more limited due to the dimensions and specific anatomy of the
elephant reproductive tract. In addition, aging of captive elephant
populations and advanced age of primiparous females make active birth
management increasingly important. Intrauterine infection, uterine
inertia and urogenital tract pathologies are emerging as major causes
for dystocia, often leading to foetal and dam death. This paper reviews
the current knowledge on elephant birth and the factors associated with
dystocia. It then summarises recommendations for birth and dystocia
management. As Caesarean section, the most common ultima ratio in
domestic animal obstetrics, is lethal and therefore not an option in the
elephant, non-invasive medical treatment, induction of the Fergusson
reflex or the conscious decision to leave a retained foetus until it is
expelled voluntarily, are key elements in elephant obstetrics. Surgical
strategies such as episiotomy and foetotomy are sometimes inevitable in
order to try to save the life of the dam, however, these interventions
result in chronic post-surgical complications or even fatal outcome.
Limited reliable data on serum calcium concentrations, and
pharmacokinetics and effect of exogenous oestrogen, oxytocin, and
prostaglandins during birth provide the scope of future research,
necessary to advance scientific knowledge on obstetrics in elephants
Liu, A.G.,
Seiffert, E.R., Simons, E.L., 2008. Stable isotope evidence for an
amphibious phase in early proboscidean evolution. Proc. Natl. Acad. Sci.
U. S. A 105, 5786-5791.
Abstract: The order Proboscidea includes extant elephants and their
extinct relatives and is closely related to the aquatic sirenians
(manatees and dugongs) and terrestrial hyracoids (hyraxes). Some
analyses of embryological, morphological, and paleontological data
suggest that proboscideans and sirenians shared an aquatic or
semiaquatic common ancestor, but independent tests of this hypothesis
have proven elusive. Here we test the hypothesis of an aquatic ancestry
for advanced proboscideans by measuring delta(18)O in tooth enamel of
two late Eocene proboscidean genera, Barytherium and Moeritherium, which
are sister taxa of Oligocene-to-Recent proboscideans. The combination of
low delta(18)O values and low delta(18)O standard deviations in
Barytherium and Moeritherium matches the isotopic pattern seen in
aquatic and semiaquatic mammals, and differs from that of terrestrial
mammals. delta(13)C values of these early proboscideans suggest that
both genera are likely to have consumed freshwater plants, although a
component of C(3) terrestrial vegetation cannot be ruled out. The
simplest explanation for the combined evidence from isotopes, dental
functional morphology, and depositional environments is that Barytherium
and Moeritherium were at least semiaquatic and lived in freshwater swamp
or riverine environments, where they grazed on freshwater vegetation.
These results lend new support to the hypothesis that
Oligocene-to-Recent proboscideans are derived from amphibious ancestors
Miller, W.,
Drautz, D.I., Ratan, A., Pusey, B., Qi, J., Lesk, A.M., Tomsho, L.P.,
Packard, M.D., Zhao, F., Sher, A., Tikhonov, A., Raney, B., Patterson,
N., Lindblad-Toh, K., Lander, E.S., Knight, J.R., Irzyk, G.P.,
Fredrikson, K.M., Harkins, T.T., Sheridan, S., Pringle, T., Schuster,
S.C., 2008. Sequencing the nuclear genome of the extinct woolly mammoth.
Nature 456, 387-390.
Abstract: In 1994, two independent groups extracted DNA from several
Pleistocene epoch mammoths and noted differences among individual
specimens. Subsequently, DNA sequences have been published for a number
of extinct species. However, such ancient DNA is often fragmented and
damaged, and studies to date have typically focused on short
mitochondrial sequences, never yielding more than a fraction of a per
cent of any nuclear genome. Here we describe 4.17 billion bases (Gb) of
sequence from several mammoth specimens, 3.3 billion (80%) of which are
from the woolly mammoth (Mammuthus primigenius) genome and thus comprise
an extensive set of genome-wide sequence from an extinct species. Our
data support earlier reports that elephantid genomes exceed 4 Gb. The
estimated divergence rate between mammoth and African elephant is half
of that between human and chimpanzee. The observed number of nucleotide
differences between two particular mammoths was approximately one-eighth
of that between one of them and the African elephant, corresponding to a
separation between the mammoths of 1.5-2.0 Myr. The estimated
probability that orthologous elephant and mammoth amino acids differ is
0.002, corresponding to about one residue per protein. Differences were
discovered between mammoth and African elephant in amino-acid positions
that are otherwise invariant over several billion years of combined
mammalian evolution. This study shows that nuclear genome sequencing of
extinct species can reveal population differences not evident from the
fossil record, and perhaps even discover genetic factors that affect
extinction
Organ, C.L.,
Schweitzer, M.H., Zheng, W., Freimark, L.M., Cantley, L.C., Asara, J.M.,
2008. Molecular phylogenetics of mastodon and Tyrannosaurus rex. Science
320, 499.
Abstract: We report a molecular phylogeny for a nonavian dinosaur,
extending our knowledge of trait evolution within nonavian dinosaurs
into the macromolecular level of biological organization. Fragments of
collagen alpha1(I) and alpha2(I) proteins extracted from fossil bones of
Tyrannosaurus rex and Mammut americanum (mastodon) were analyzed with a
variety of phylogenetic methods. Despite missing sequence data, the
mastodon groups with elephant and the T. rex groups with birds,
consistent with predictions based on genetic and morphological data for
mastodon and on morphological data for T. rex. Our findings suggest that
molecular data from long-extinct organisms may have the potential for
resolving relationships at critical areas in the vertebrate evolutionary
tree that have, so far, been phylogenetically intractable
Steenkamp,
G., Ferguson, W.H., Boy, S.C., Ferreira, S.M., Bester, M.N., 2008.
Estimating exposed pulp lengths of tusks in the African elephant
(Loxodonta africana africana). J. S. Afr. Vet. Assoc. 79, 25-30.
Abstract: Captive and wild African elephants frequently suffer tusk
fractures. Several institutions shorten the tusks of captive elephants
to reduce fractures and injury as a result of behaviour within
enclosures. Fracturing or coronal amputations that expose pulp lead to
pain for the elephant. Estimating coronal pulp lengths may thus help to
minimise the risk of pulp exposure during amputations. We aimed to
determine the length of the pulp beyond the lip margin from an external
tusk characteristic. Tusks collected from elephants in Namibia and the
Kruger National Park had similar morphological relationships. This
statistical property allowed us to correct for missing data in our data
sets. Pulp volume and pulp length correlated with tusk circumference at
the lip. Even so, the circumference at the lip could not predict the
length of the pulp in the crown external to the lip. Our findings
suggest that tusks, irrespective of sex or age, amputated further than
300 mm from the lip should not expose pulp
Thongtip, N.,
Saikhun, J., Mahasawangkul, S., Kornkaewrat, K., Pongsopavijitr, P.,
Songsasen, N., Pinyopummin, A., 2008. Potential factors affecting semen
quality in the Asian elephant (Elephas maximus). Reprod. Biol.
Endocrinol. 6, 9.
Abstract: BACKGROUND: One of the major obstacles in using artificial
insemination to manage genetics of elephant population in captivity is
the large variations in semen quality among ejaculates within the same
and among individuals. The objectives of this study were to determine
the influences of (1) age (2) seasonality (3) and circulating
testosterone (SrTest), triiodothyronine (SrT3) and tetraiodothyronine
(SrT4), as well as seminal (4) testosterone (SpTest), zinc (SpZn) and
protein (SpTP) on semen quality in the Asian elephant METHODS: Analyses,
including motility, viability and morphology were performed in semen
samples collected twice monthly from 13 elephant bulls (age range, 10-to
72-years) by manual stimulation between July 2004 and June 2005. Serum
samples obtained monthly were assessed for SrTest, SrT3, SrT4, and
seminal plasma samples were evaluated for, SpTest, SpZn and SpTP.
RESULTS: The highest semen quality was observed at age 23 to 43 years.
Percentages of progressive motility and viable sperm were lowest at age
51 to 70 years (P < 0.05); on the other hand, sperm concentration was
lowest at age 10 to 19 years (P < 0.05). Percentage of sperm with normal
morphology was highest at age 23 to 43 years. The levels of SrT3, SrTest,
SpTest and SpZn were lowest at age 51 to 70 years, whereas SrT4 was
lowest at age 23 to 43 years. Seasonality significantly affected semen
characteristics in which percentage of viable sperm and cell
concentration were highest during rainy season and lowest during summer
months (P < 0.05). However, percentage of sperm with normal morphology
was highest in summer and lowest in rainy season (P < 0.05). Seasonality
significantly influenced SrTest with elevated concentrations observed in
rainy season and winter (P < 0.05). CONCLUSION: This study indicates
that age and seasonality had influence on semen characteristics in the
Asian elephant. The knowledge obtained in this study will improve our
understanding of the reproductive biology of this species
Valeix, M.,
Fritz, H., Matsika, R., Matsvimbo, F., Madzikanda, H., 2008. The role of
water abundance, thermoregulation, perceived predation risk and
interference competition in water access by African herbivores. African
Journal of Ecology 46, 402-410.
Abstract: In African savannas, surface water can become limiting and an
understanding of how animals address the trade-offs between different
constraints to access this resource is needed. Here, we describe water
access by ten African herbivore species in Hwange National Park,
Zimbabwe. and we explore four possible determinants of the observed
behaviours: water abundance, thermoregulation, perceived predation risk
and interference competition. On average, herbivores were observed to
drink in 80% of visits to a waterhole. The probability of drinking was
higher in 2003 (474 mm) than in 2004 (770 mm), and at the end of the dry
season than at its beginning. For larger species, this probability may
also be related to risks of interference competition with elephants or
other herbivores. For smaller species, this probability may also be
related to the perceived risk of predation. We also investigate the time
spent accessing water to drink. The influence of herd size and the
presence of young on the time spent accessing water for most species
suggests that perceived predation risk plays a role. Themoregulation
also affects this time: during the hottest periods, herbivores spend
less time in open areas. unless when wind is strong, probably owing to
evapotranspired heat loss.
Bates, L.A., Byrne, R.W., 2007.
Creative or
created: using anecdotes to investigate animal cognition. Methods 42,
12-21.
Abstract: In non-human animals, creative behaviour occurs spontaneously
only at low frequencies, so is typically missed by standardised
observational methods. Experimental approaches have tended to rely
overly on paradigms from child development or adult human cognition,
which may be inappropriate for species that inhabit very different
perceptual worlds and possess quite different motor capacities than
humans. The analysis of anecdotes offers a solution to this impasse,
provided certain conditions are met. To be reliable, anecdotes must be
recorded immediately after observation, and only the records of
scientists experienced with the species and the individuals concerned
should be used. Even then, interpretation of a single record is always
ambiguous, and analysis is feasible only when collation of multiple
records shows that a behaviour pattern occurs repeatedly under similar
circumstances. This approach has been used successfully to study a
number of creative capacities of animals: the distribution, nature and
neural correlates of deception across the primate order; the occurrence
of teaching in animals; and the neural correlates of several
aptitudes--in birds, foraging innovation, and in primates, innovation,
social learning and tool-use. Drawing on these approaches, we describe
the use of this method to investigate a new problem, the cognition of
the African elephant, a species whose sheer size and evolutionary
distance from humans renders the conventional methods of comparative
psychology of little use. The aim is both to chart the creative
cognitive capacities of this species, and to devise appropriate
experimental methods to confirm and extend previous findings
Bouley, D.M.,
Alarcón, C.N., Hildebrandt, T., O'connell-Rodwell, C.E., ., 2007. The
distribution, density and three-dimensional histomorphology of Pacinian
corpuscles in the foot of the Asian elephant (Elephas maximus) and their
potential role in seismic communication. J Anat 211, 428-435.
Abstract: Both Asian (Elephas maximus) and African (Loxodonta africana)
elephants produce low-frequency, high-amplitude rumbles that travel well
through the ground as seismic waves, and field studies have shown that
elephants may utilize these seismic signals as one form of
communication. Unique elephant postures observed in field studies
suggest that the elephants use their feet to 'listen' to these seismic
signals, but the exact sensory mechanisms used by the elephant have
never been characterized. The distribution, morphology and tissue
density of Pacinian corpuscles, specialized mechanoreceptors, were
studied in a forefoot and hindfoot of Asian elephants. Pacinian
corpuscles were located in the dermis and distal digital cushion and
were most densely localized to the anterior, posterior, medial and
lateral region of each foot, with the highest numbers in the anterior
region of the forefoot (52.19%) and the posterior region of the hindfoot
(47.09%). Pacinian corpuscles were encapsulated, had a typical lamellar
structure and were most often observed in large clusters.
Three-dimensional reconstruction through serial sections of the dermis
revealed that individual Pacinian corpuscles may be part of a cluster.
By studying the distribution and density of these mechanoreceptors, we
propose that Pacinian corpuscles are one possible anatomic mechanism
used by elephants to detect seismic waves.
Gunga, H.C.,
Suthau, T., Bellmann, A., Friedrich, A., Schwanebeck, T., Stoinski, S.,
Trippel, T., Kirsch, K., Hellwich, O., 2007. Body mass estimations for
Plateosaurus engelhardti using laser scanning and 3D reconstruction
methods. Naturwissenschaften 94, 623-630.
Abstract: Both body mass and surface area are factors determining the
essence of any living organism. This should also hold true for an
extinct organism such as a dinosaur. The present report discusses the
use of a new 3D laser scanner method to establish body masses and
surface areas of an Asian elephant (Zoological Museum of Copenhagen,
Denmark) and of Plateosaurus engelhardti, a prosauropod from the Upper
Triassic, exhibited at the Paleontological Museum in Tubingen (Germany).
This method was used to study the effect that slight changes in body
shape had on body mass for P. engelhardti. It was established that body
volumes varied between 0.79 m(3) (slim version) and 1.14 m(3) (robust
version), resulting in a presumable body mass of 630 and 912 kg,
respectively. The total body surface areas ranged between 8.8 and 10.2
m(2), of which, in both reconstructions of P. engelhardti, approximately
33% account for the thorax area alone. The main difference between the
two models is in the tail and hind limb reconstruction. The tail of the
slim version has a surface area of 1.98 m(2), whereas that of the robust
version has a surface area of 2.73 m(2). The body volumes calculated for
the slim version were as follows: head 0.006 m(3), neck 0.016 m(3), fore
limbs 0.020 m(3), hind limbs 0.08 m(3), thoracic cavity 0.533 m(3), and
tail 0.136 m(3). For the robust model, the following volumes were
established: 0.01 m(3) head, neck 0.026 m(3), fore limbs 0.025 m(3),
hind limbs 0.18 m(3), thoracic cavity 0.616 m(3), and finally, tail 0.28
m(3). Based on these body volumes, scaling equations were used to assess
the size that the organs of this extinct dinosaur have
Hildebrandt,
T., Drews, B., Gaeth, A.P., Goeritz, F., Hermes, R., Schmitt, D., Gray,
C., Rich, P., Streich, W.J., Short, R.V., Renfree, M.B., 2007. Foetal
age determination and development in elephants. Proc. Biol. Sci. 274,
323-331.
Abstract: Elephants have the longest pregnancy of all mammals, with an
average gestation of around 660 days, so their embryonic and foetal
development have always been of special interest. Hitherto, it has only
been possible to estimate foetal ages from theoretical calculations
based on foetal mass. The recent development of sophisticated ultrasound
procedures for elephants has now made it possible to monitor the growth
and development of foetuses of known gestational age conceived in
captivity from natural matings or artificial insemination. We have
studied the early stages of pregnancy in 10 captive Asian and 9 African
elephants by transrectal ultrasound. Measurements of foetal crown-rump
lengths have provided the first accurate growth curves, which differ
significantly from the previous theoretical estimates based on the cube
root of foetal mass. We have used these to age 22 African elephant
foetuses collected during culling operations. Pregnancy can be first
recognized ultrasonographically by day 50, the presumptive yolk sac by
about day 75 and the zonary placenta by about day 85. The trunk is first
recognizable by days 85-90 and is distinct by day 104, while the first
heartbeats are evident from around day 80. By combining ultrasonography
and morphology, we have been able to produce the first reliable criteria
for estimating gestational age and ontological development of Asian and
African elephant foetuses during the first third of gestation.
Kinahan, A.A.,
Pimma, S.L., van Aarde, R.J., 2007. Ambient temperature as a determinant
of landscape use in the savanna elephant, Loxodonta africana. Journal of
Thermal Biology 32, 47-58.
Abstract: Elephants occur in landscapes where temperatures can reach 50
degrees C. Due to their large size they may face physiological problems
of dissipating heat during such high temperatures. In spite of this, no
one seems to have considered ambient temperature as limiting landscape
choices in elephants. We recorded hourly landscape use in free-ranging
elephants using GPS collars. We also placed temperature data loggers in
each of the landscapes, to obtain corresponding ambient temperatures for
each hour. Our results suggest that elephants may select landscapes
based on the rate at which temperatures changed and also for shade. We
suggest that these selected variables provide a thermal benefit to
individuals. As such, we propose that landscape use in elephants may be
constrained by their thermal physiological requirements as well as other
resources such as food and water.
Murphy, W.J., Pringle, T.H., Crider, T.A., Springer, M.S., Miller, W.,
2007.
Using genomic data to unravel the root of the placental mammal
phylogeny. Genome Res. 17, 413-421.
Abstract: The phylogeny of placental mammals is a critical framework for
choosing future genome sequencing targets and for resolving the
ancestral mammalian genome at the nucleotide level. Despite considerable
recent progress defining superordinal relationships, several branches
remain poorly resolved, including the root of the placental tree. Here
we analyzed the genome sequence assemblies of human, armadillo,
elephant, and opossum to identify informative coding indels that would
serve as rare genomic changes to infer early events in placental mammal
phylogeny. We also expanded our species sampling by including sequence
data from >30 ongoing genome projects, followed by PCR and sequencing
validation of each indel in additional taxa. Our data provide support
for a sister-group relationship between Afrotheria and Xenarthra (the
Atlantogenata hypothesis), which is in turn the sister-taxon to
Boreoeutheria. We failed to recover any indels in support of a basal
position for Xenarthra (Epitheria), which is suggested by morphology and
a recent retroposon analysis, or a hypothesis with Afrotheria basal (Exafricoplacentalia),
which is favored by phylogenetic analysis of large nuclear gene data
sets. In addition, we identified two retroposon insertions that also
support Atlantogenata and none for the alternative hypotheses. A revised
molecular timescale based on these phylogenetic inferences suggests
Afrotheria and Xenarthra diverged from other placental mammals
approximately 103 (95-114) million years ago. We discuss the impacts of
this topology on earlier phylogenetic reconstructions and repeat-based
inferences of phylogeny
O'Connell-Rodwell,
C.E., 2007. Keeping an "ear" to the ground: seismic communication in
elephants. Physiology (Bethesda) 287-294.
Abstract: This review explores the mechanisms that elephants may use to
send and receive seismic signals from a physical, anatomical,
behavioral, and physiological perspective. The implications of the use
of the vibration sense as a multimodal signal will be discussed in light
of the elephant's overall fitness and survival.
Roca, A.L.,
Georgiadis, N., O'Brien, S.J., 2007. Cyto-nuclear genomic dissociation
and the African elephant species question. Quat. Int. 169-170,
4-16.
Abstract: Studies of skull morphology and of nuclear DNA have strongly
concluded that African elephants comprise two species. Nonetheless,
Debruyne (2005) has suggested a single-species model for Loxodonta based
on the polyphyly of a single genetic locus, mitochondrial DNA (mtDNA).
Discordant patterns between mitochondrial and nuclear DNA markers were
subsequently reported in some African savanna elephant populations,
further supporting a two-species model, and prompting us to re-examine
here the geographic distribution of different elephant morphotypes and
their relationship to nuclear and mtDNA phylogeographic patterns. We
used exact tests to compare the distribution of forest elephant-typical
and savanna elephant-typical characteristics across eight published
datasets containing morphological, mtDNA or nuclear DNA data for African
elephants. Among the elephants examined by Debruyne (2005), we found
that patterns of forest vs. savanna characteristics were significantly
different (p < 10(-5)) between mtDNA and morphology, suggesting the
presence of cyto-nuclear genomic dissociation. We show that the eight
African elephant continent-wide datasets compared, including that of
Debruyne (2005), together support a two-species model with cyto-nuclear
genomic dissociation rather than a one-species model, and together
indicate that Africa harbors two species of elephant
Tabuce, R.,
Marivaux, L., Adaci, M., Bensalah, M., Hartenberger, J.L., Mahboubi, M.,
Mebrouk, F., Tafforeau, P., Jaeger, J.J., 2007. Early Tertiary mammals
from North Africa reinforce the molecular Afrotheria clade. Proc. Biol.
Sci. 274, 1159-1166.
Abstract: The phylogenetic pattern and timing of the radiation of
mammals, especially the geographical origins of major crown clades, are
areas of controversy among molecular biologists, morphologists and
palaeontologists. Molecular phylogeneticists have identified an
Afrotheria clade, which includes several taxa as different as tenrecs (Tenrecidae),
golden moles (Chrysochloridae), elephant-shrews (Macroscelididae),
aardvarks (Tubulidentata) and paenungulates (elephants, sea cows and
hyracoids). Molecular data also suggest a Cretaceous African origin for
Afrotheria within Placentalia followed by a long period of endemic
evolution on the Afro-Arabian continent after the mid-Cretaceous
Gondwanan breakup (approx. 105-25 Myr ago). However, there was no
morphological support for such a natural grouping so far. Here, we
report new dental and postcranial evidence of Eocene stem hyrax and
macroscelidid from North Africa that, for the first time, provides a
congruent phylogenetic view with the molecular Afrotheria clade. These
new fossils imply, however, substantial changes regarding the historical
biogeography of afrotheres. Their long period of isolation in Africa, as
assumed by molecular inferences, is now to be reconsidered inasmuch as
Eocene paenungulates and elephant-shrews are here found to be related to
some Early Tertiary Euramerican 'hyopsodontid condylarths' (archaic
hoofed mammals). As a result, stem members of afrotherian clades are not
strictly African but also include some Early Paleogene Holarctic mammals
Witter, K., Egger, G.F., Boeck, P., 2007.
Renaut bodies
in nerves of the trunk of the African elephant, Loxodonta africana. J.
Morphol. 268, 414-422.
Abstract: Renaut bodies are loosely textured, cell-sparse structures in
the subperineurial space of peripheral nerves, frequently found at sites
of nerve entrapment. The trunk of the elephant is a mobile, richly
innervated organ, which serves for food gathering, object grasping and
as a tactile organ. These functions of the trunk lead to distortion and
mechanical compression of its nerves, which can therefore be expected to
contain numerous Renaut bodies. Samples of the trunk wall of an adult
African elephant (Loxodonta africana) were examined histologically using
conventional staining methods, immunohistochemistry, and lectin
histochemistry. Architecture of nerve plexuses and occurrence of Renaut
bodies in the elephant trunk were compared with those in tissues
surrounding the nasal vestibule of the pig. Prominent nerve plexuses
were found in all layers of the elephant trunk. Almost all (81%) nerve
profiles contained Renaut bodies, a basophilic, discrete subperineurial
layer resembling cushions around the nerve core. In contrast, Renaut
bodies were seen in only 15% of nerve profiles in the porcine nasal
vestibule. Within Renaut bodies, fusiform fibroblasts and round,
ruff-like cells were placed into a matrix of acidic glycosaminoglycans
with delicate collagen and very few reticular fibers. The turgor of this
matrix is thought to protect nerves against compression and shearing
strain. Renaut bodies are readily stained with alcian blue (pH 2.5)
favorably in combination with immunohistochemical markers of nerve
fibers. They should be regarded as a physiological response to repeated
mechanical insults and are distinct from pathological alterations.
alterations
Allen, W.R.,
2006. Ovulation, pregnancy, placentation and husbandry in the African
elephant (Loxodonta africana)
470. Philos. Trans. R. Soc. Lond B Biol. Sci. 361, 821-834.
Abstract: The African elephant reproduces so efficiently in the wild
that overpopulation is now a serious problem in some game parks in
Zimbabwe, Botswana and South Africa. The female reaches puberty between
10 and 12 years of age in the wild and, when in captivity, shows
oestrous cycles of 14-15 weeks duration. She readily conceives a
singleton in the wild yet her uterus has the capacity for twins. She
shows a gestation length of 22 months and, in the wild, shows a
population density and feed dependent intercalving interval of 4-8
years. The trophoblast erodes the lumenal epithelium of the endometrium
and stimulates upgrowths of blood vessel-containing stromal villi, which
develop eventually into the broad, tightly folded lamellae of the zonary,
endotheliochorial placenta. Significant quantities of leaked maternal
erythrocytes and ferric iron are phagocytosed by specialized trophoblast
cells in the haemophagous zones at the lateral edges of the placental
band. Although the placenta itself is endocrinologically inert, the
foetal gonads, which enlarge greatly during the second half of pregnancy
can synthesize 5alpha-dihydryoprogesterone and other 5alpha pregnane
derivatives from cholesterol and pregnenolone. These products may
synergize with progestagens secreted by the 2-8 large corpora lutea
which are always present in the maternal ovaries throughout gestation to
maintain the pregnancy state
Benz, A.,
Zenker, W., Hildebrandt, T.B., Weissengruber, G., Geyer, H. Recent
findings about the macroscopic and microscopic morphology of the
elephants hooves (Elephantidae). Proceedings International Elephant
Conservation & Research Symposium. 38-41. 2006. 2006.
Ref Type: Conference Proceeding
Bertschinger,
H., Delsink, A., Kirkpatrick, J.F., Human, A., Grobler, D., van Altena,
J.J. Management of elephant populations in private South African game
reserves with porcine zona pellucida vaccine. 2006 Proceedings American
Association of Zoo Veterinarians. 283-285. 2006.
Ref Type: Conference Proceeding
Abstract: Control of African elephant populations has become an absolute
necessity in a number of game reserves in southern Africa. The two main
methods used to control populations so far are culling and
translocation. Culling, besides being regarded as inhumane and
unacceptable in many quarters, is not suitable for smaller populations.
It requires that whole family units are culled simultaneously which
could mean that in reserves with 10 to 50 elephants a considerable
portion, if not the entire population, is killed. As far as
translocation is concerned, limited new space is available for
elephants. The only alternative to the two above options is to control
the rate of reproduction. The porcine zona pellucida (pZP) vaccine has
been used to successfully contracept wild horses and other wildlife
species. Work on the contraception of African elephants was initiated
in the Kruger National Park in 1995 when the potential for using the
porcine zona pellucida (pZP) was investigated. Subsequently the first
field trials on wild elephants were carried out in Kruger and the
results clearly showed that elephants could be contracepted with the pZP
vaccine, although the efficacy achieved was 80%. During these field
trials safety and reversibility werecould be demonstrated. In 2000 an
elephant contraceptive program was initiated at Makalali Private Game
Reserve, RSA, which has become the flagship model for immunocontrol in
African elephants. The preliminary findings have been reported in three
publications.During the first year, all 18 cows that were individually
identified and older than 12 yr of age were treated. During the next 4
yr the number of cows contracepted increased to 23 as young animals were added to the program. The
standard vaccination procedure during the first year consisted of a
primary vaccination (600 μg or 400 μg pZP with 0.5 ml Freund's modified
complete adjuvant) followed by boosters (200 μg pZP with 0.5 ml Freund's
incomplete
adjuvant) at 3 to 6-wk intervals. Annual boosters to maintain antibody
titers and contraceptive effect followed. To date, the success rate on
cows that have passed reserve-specific intercalving period of 56 mo has
been 100%. The population stabilized within 3 yr by which time when all
cows that had been pregnant at the time of first vaccination in 2000 had
calved. Once again safety during pregnancy (14 cows pregnant at 2-21 mo
gestation when first treated gave birth to normal healthy calves) as
well as side effects that were limited to occasional lumps at the site
of vaccination could be shown. Following ground darting, behavioral
patterns returned to pre-darting status within 2 days. During 2003 and
2004 most boosters were administered from a helicopter; whereas,
previously they had been done from a vehicle or on foot. In all cases,
drop-out darts were used. Time taken for vaccination from helicopter
take-off to landing was about 30 min (1.5 min per cow; 30 min for total
time). This required prior knowledge of the locations of family units or
that an individual in each unit is radio-collared. Herds settled down
much more quickly (1-2 days) than if darted from the ground. Since then
we have vaccinated another 107 elephant cows in eight game reserves.
The cow populations have ranged from 4 to 43. In one of the reserves,
Mabula, RSA, two of the four cows vaccinated have passed the mean
intercalving intervals of the reserve with neither of them producing a
calf. Treatment at the remaining reserves was initiated in 2004 or 2005
and it is too early to evaluate results. The most difficult reserve in
terms of the vaccination process was Welgevonden, RSA, (35 000 ha) with
43 cows. The reserve is mountainous and heavily wooded. None of the
elephants were collared and individuals could not be easily identified
on the day of primary vaccination. The total flying time during which
individuals were identified and vaccinated was 4.5 hr. Administration
of the first booster took about 2 hr to locate and vaccinate each cow.
Between the first and second booster the first rains occurred, followed
by the spring flush of the vegetation. By the time the second booster
was attempted late in November, the trees all had foliage. Only half the
cows were located and darted because the elephants were very difficult
to spot under the tree canopies. The valuable lessons we learned from
this were: 1) that helicopter vaccinations should be performed when most
trees are bare, and 2) when larger populations are vaccinated repeatedly
during the first year, one cow in each family unit should be
radio-collared. This makes rapid location of each unit possible and cuts
down on the major cost factor that is flying time. Elephant behavior is
being monitored in all eight reserves where contraception is being
applied. Because most of them have been contracepted recently, only the
data from Makalali is available. The elephants at Makalali have been
monitored intensively almost on a daily basis. To date, no anomalies in
terms of aggressive or indifferent behavior with regards to nursing
time, nursing behavior and calf proximity have been noted. No change in
the cows' social hierarchy has been noted. Since January 2003, a total
of 15 heats were observed in 10 cows (nine in 2003 and six in 2004) with
four mating episodes. For the same period, 38 musth occasions were seen
in five bulls (26 in 2003 and 12 in 2004). These occasions include musth
displayed in the same bull during consecutive days or within the same
musth cycle. The greatest occurrence of musth was recorded in the
largest, dominant bull. Bulls were not observed harassing or separating
cows off from their herds or calves as a result of increased estrous
frequency. Thus, the Makalali program demonstrates that pZP does not
cause herd fragmentation, harassment by bulls, change in rank and other
negative behaviors normally associated with hormonal contraceptives. In
conclusion we feel that it is important to emphasize the following
points: The pZP vaccine can be used successfully to contracept African
elephants The vaccine is safe during pregnancy and has no negative
effect on birth or calf raising It has no side effects other than
occasional swelling at the site of vaccination It is reversible Other
than an increased incidence of heat no behavioral side effects were
seen.
Drews, B.,
Göritz, F., Hermes, R., Streich, J.W., Rich, P., Schmitt, D., Lung, N.,
Renfree, M.B., Gaeth, A.P., Short, R.V., Hildebrandt, T.B. Morphological
and ultrasonographic characterization of the embryonic development in
elephants. Proceedings International Elephant Conservation & Research
Symposium. 82-83. 2006. 2006.
Ref Type: Conference Proceeding
Fischer,
M.S., Blickhan, R., 2006. The tri-segmented limbs of therian mammals:
kinematics, dynamics, and self-stabilization--a review
397. J. Exp. Zool. A Comp Exp. Biol. 305, 935-952.
Abstract: The evolution of therian mammals is to a large degree marked
by changes in their motion systems. One of the decisive transitions has
been from the sprawled, bi-segmented to the parasagittal, tri-segmented
limb. Here, we review aspects of the tri-segmented limb in locomotion
which have been elucidated in our research groups in the last 10 years.
First, we report the kinematics of the tri-segmented therian limb from
mouse to elephant in order to explore general principles of the therian
limb configuration and locomotion. Torques will be reported from a
previous paper (Witte et al., 2002. J Exp Biol 205:1339-1353) for a
better understanding of the anti-gravity work of all limb joints. The
stability of a limb in z-configuration will be explained and its
advantage with respect to other potential solutions from modeling will
be discussed. Finally, we describe how the emerging concept of
self-stability can be explained for a tri-segmented leg template and how
it affects the design of the musculoskeletal system and the operation of
legs during locomotion. While locomotion has been considered as mainly a
control problem in various disciplines, we stress the necessity to
reduce control as much as possible. Central control can be cheap if the
limbs are "intelligent" by means of their design. Gravity-induced
movements and self-stability seem to be energy-saving mechanisms
Hofreiter, M., Lister, A., 2006. Mammoths
459.
Curr. Biol. 16, R347-R348.
Schmitt, D.,
Cartmill, M., Griffin, T.M., Hanna, J.B., Lemelin, P., 2006. Adaptive
value of ambling gaits in primates and other mammals
460. J. Exp. Biol. 209, 2042-2049.
Abstract: At speeds between the walk and the gallop, most mammals trot.
Primates almost never trot, and it has been claimed that they transition
directly from a walk to a gallop without any distinctive mid-speed
running gait. If true, this would be another characteristic difference
between the locomotion of primates and that of most other quadrupedal
mammals. Presently, however, few data exist concerning the actual
presence or absence of intermediate-speed gaits (i.e. gaits that are
used between a walk and a gallop) in primates. Video records of running
in twelve primate species reveal that, unlike most other mammals, all
the primates studied almost exclusively adopt an 'amble'--an
intermediate-speed running gait with no whole-body aerial phase--rather
than trot. Ambling is also common in elephants and some horses, raising
the question of why ambling is preferred over trotting in these diverse
groups of animals. Mathematical analyses presented here show that
ambling ensures continuous contact of the body with the substrate while
dramatically reducing vertical oscillations of the center of mass. This
may explain why ambling appears to be preferable to trotting for
extremely large terrestrial mammals such as elephants and for arboreal
mammals like primates that move on unstable branches. These findings
allow us to better understand the mechanics of these unusual running
gaits and shed new light on primate locomotor evolution
Shoshani, J.,
Kupsky, W.J., Marchant, G.H., 2006. Elephant brain. Part I: gross
morphology, functions, comparative anatomy, and evolution. Brain Res
Bull 70, 124-157.
Abstract: We report morphological data on brains of four African,
Loxodonta africana, and three Asian elephants, Elephas maximus, and
compare findings to literature. Brains exhibit a gyral pattern more
complex and with more numerous gyri than in primates, humans included,
and in carnivores, but less complex than in cetaceans. Cerebral frontal,
parietal, temporal, limbic, and insular lobes are well developed,
whereas the occipital lobe is relatively small. The insula is not as
opercularized as in man. The temporal lobe is disproportionately large
and expands laterally. Humans and elephants have three parallel temporal
gyri: superior, middle, and inferior. Hippocampal sizes in elephants and
humans are comparable, but proportionally smaller in elephant. A
possible carotid rete was observed at the base of the brain. Brain size
appears to be related to body size, ecology, sociality, and longevity.
Elephant adult brain averages 4783 g, the largest among living and
extinct terrestrial mammals; elephant neonate brain averages 50% of its
adult brain weight (25% in humans). Cerebellar weight averages 18.6% of
brain (1.8 times larger than in humans). During evolution,
encephalization quotient has increased by 10-fold (0.2 for extinct
Moeritherium, approximately 2.0 for extant elephants). We present 20
figures of the elephant brain, 16 of which contain new material.
Similarities between human and elephant brains could be due to
convergent evolution; both display mosaic characters and are highly
derived mammals. Humans and elephants use and make tools and show a
range of complex learning skills and behaviors. In elephants, the large
amount of cerebral cortex, especially in the temporal lobe, and the
well-developed olfactory system, structures associated with complex
learning and behavioral functions in humans, may provide the substrate
for such complex skills and behavior.
Shoshani, J.,
Walter, R.C., Abraha, M., Berhe, S., Tassy, P., Sanders, W.J., Marchant,
G.H., Libsekal, Y., Ghirmai, T., Zinner, D., 2006. A proboscidean from
the late Oligocene of Eritrea, a "missing link" between early
Elephantiformes and Elephantimorpha, and biogeographic implications
384. Proc. Natl. Acad. Sci. U. S. A 103, 17296-17301.
Abstract: We report on a late Oligocene proboscidean species from
Eritrea, dated to 26.8 +/- 1.5 Mya. This "missing link" between early
elephantiformes and Elephantimorpha is the oldest known nongomphothere
proboscidean to probably display horizontal tooth displacement, typical
of elephants [Elephantimorpha consists of Mammutida (mastodons) and
Elephantida, and Elephantida includes gomphotheres, stegodons, and
elephants]. Together with the newly discovered late Oligocene
gomphotheres from Chilga, Ethiopia, the Eritrean taxon points to the
importance of East Africa as a major area for the knowledge of the early
evolution of Elephantimorpha before the faunal exchange between Eurasia
and Africa
Shoshani, J.,
Kupsky, W.J., Marchant, G.H., 2006. Elephant brain. Part I: gross
morphology, functions, comparative anatomy, and evolution
446. Brain Res. Bull. 70, 124-157.
Abstract: We report morphological data on brains of four African,
Loxodonta africana, and three Asian elephants, Elephas maximus, and
compare findings to literature. Brains exhibit a gyral pattern more
complex and with more numerous gyri than in primates, humans included,
and in carnivores, but less complex than in cetaceans. Cerebral frontal,
parietal, temporal, limbic, and insular lobes are well developed,
whereas the occipital lobe is relatively small. The insula is not as
opercularized as in man. The temporal lobe is disproportionately large
and expands laterally. Humans and elephants have three parallel temporal
gyri: superior, middle, and inferior. Hippocampal sizes in elephants and
humans are comparable, but proportionally smaller in elephant. A
possible carotid rete was observed at the base of the brain. Brain size
appears to be related to body size, ecology, sociality, and longevity.
Elephant adult brain averages 4783 g, the largest among living and
extinct terrestrial mammals; elephant neonate brain averages 50% of its
adult brain weight (25% in humans). Cerebellar weight averages 18.6% of
brain (1.8 times larger than in humans). During evolution,
encephalization quotient has increased by 10-fold (0.2 for extinct
Moeritherium, approximately 2.0 for extant elephants). We present 20
figures of the elephant brain, 16 of which contain new material.
Similarities between human and elephant brains could be due to
convergent evolution; both display mosaic characters and are highly
derived mammals. Humans and elephants use and make tools and show a
range of complex learning skills and behaviors. In elephants, the large
amount of cerebral cortex, especially in the temporal lobe, and the
well-developed olfactory system, structures associated with complex
learning and behavioral functions in humans, may provide the substrate
for such complex skills and behavior
Siegal-Willott, J., Isaza, R., Johnson, R., Blaik, M. Clinical
evaluation of distal limb radiography and growth plate closure in the
juvenile Asian elephant (Elephas maximus).
2006 Proceedings American Association of Zoo Veterinarians. 181-182.
2006.
Ref Type: Conference Proceeding
Abstract: The thoracic limb digits of 11 healthy juvenile Asian
elephants (Elephas maximus) were evaluated radiographically to assess
normal developmental anatomy. Parameters evaluated included: the
location(s) of centers of ossification, relative age at time of
phalangeal ossification, and relative times of growth plate closure in
the bones of the distal forelimb. Specifically, the third phalanx (P3)
of each digit was evaluated, as well as the first (P1) and second (P2)
phalanges of the third digit (D3). A retrospective evaluation of
radiographs from juvenile elephants was also done to augment the data
set. This study reports the methods used to obtain high-quality
radiographs of the elephant foot, the locations of centers of
ossification based on radiographic evaluation, and the relative times of
growth plate closure within the digital bones. The settings used to
obtain the radiographs used in this study for P3 are presented in Table
1. Radiographs of D3, P1, and P2 were obtained in a similar manner,
using a 45° angle for focal spot positioning. The kilovoltage power and
milliampere seconds were adjusted as needed. Radiographic evaluation of
the juvenile Asian elephants revealed variability in the shape of P3
based on age of the animal and degree of ossification of P3. The
relative times of growth plate closure and number of ossifications were
also determined. The information presented will help clinicians in
radiographing elephants, interpreting foot radiographs, and recognizing
normal versus abnormal anatomy. It will also help in aging juvenile
elephants, investigating diseases and deaths, and recognizing normal
patterns of toe and foot development.
Takahashi,
H., Yamashita, M., Shigehara, N., 2006. Cranial photographs of mammals
on the web: The Mammalian Crania Photographic Archive (MCPA2) and a
comparison of bone image databases. Anthropological Science 114,
217-222.
Abstract: The Mammalian Crania Photographic Archive (MCPA2) is a website
(http://1kai.dokkyomed.ac.jp/mammal/en/mammal.html) that includes a
collection of 10,950 photographs of mammalian crania, which have been
taken with a high-resolution digital camera. In the present report, we
outline the characteristics of MCPA2 and how it was created, and make
brief comparisons with several similar websites currently accessible via
the internet. The archived MCPA2 materials include 1825 cranial
specimens, ranging from insectivores to elephants, which have been
macerated in Japan during the past 35 years and prepared for
osteological study. Of the 16 orders represented in the database,
primates comprise the major group with 704 specimens. Each cranium was
placed with the orbitomeatal (Frankfort) or palatine plane horizontal,
and was photographed in six perpendicular views from a long distance
using a telephoto or telemacro lens. These long-distance shots decrease
perspective distortion that lead to measurement errors when studying
cranial profiles and landmark positions, and enable detailed observation
and measurement of specific bony characteristics on a computer screen.
From our website, images can be searched using (1) the taxonomic table,
(2) Japanese name, (3) English name, and (4) scientific name. In the
page of search results, in addition to the images, four caliper
measurements and additional text (taxonomy, sex, and age) are available
for every specimen.
Uni, S.,
Bain, O., Agatsuma, T., Katsumi, A., Baba, M., Yanai, T., Takaoka, H.,
2006. New filarial nematode from Japanese serows (Naemorhedus crispus:
Bovidae) close to parasites from elephants
403. Parasite 13, 193-200.
Abstract: A new onchocercid species, Loxodontofilaria caprini n. sp. (Filarioidea:
Nematoda), found in subcutaneous tissues of 37 (33%) of 112 serows (Noemorhedus
crispus) examined in Japan, is described. The female worm had the
characteristics of Loxodontofilaria, e.g., the large body size,
well-developed esophagus with a shallow buccal cavity, and the long tail
with three caudal lappets. The male worm of the new species, which was
first described in the genus, had unequal length of spicules, 10 pairs
of pre- and post-caudal papillae, and three terminal caudal lappets.
Deirids were present in both sexes. Among four species of the genus
loxodontofiloria: one from the hippopotamus and three from the
Elepantidae, L. caprini n. sp. appears close to L. asiatica Bain, Baker
& Chabaud, 1982, a subcutaneous parasite of Elephas indicus in Myanmar
(Burma). However, L. caprini n. sp. is distinct from L. asiatica in that
the Japanese female worm has an esophagus half as long and the
microfilariae also half as long with a coiled posterior. The
microfilariae were found in the skin of serows. The new parasite appears
to clearly illustrate a major event in the evolution of onchocercids:
the host-switching. This might have occurred on the Eurasian continent,
where elephantids and the lineage of rupicaprines diversified during the
Pliocene-Pleistocene, or in Japan, into which some of these hosts
migrated
Weissengruber,
G.E., Fuss, F.K., Egger, G., Stanek, G., Hittmair, K.M., Forstenpointner,
G., 2006. The elephant knee joint: morphological and biomechanical
considerations
513. Journal of Anatomy 208, 59-72.
Abstract: Elephant limbs display unique morphological features which are
related mainly to supporting the enormous body weight of the animal. In
elephants, the knee joint plays important roles in weight bearing and
locomotion, but anatomical data are sparse and lacking in functional
analyses. In addition, the knee joint is affected frequently by
arthrosis. Here we examined structures of the knee joint by means of
standard anatomical techniques in eight African (Loxodonta africana) and
three Asian elephants (Elephas maximus). Furthermore, we performed
radiography in five African and two Asian elephants and magnetic
resonance imaging (MRI) in one African elephant. Macerated bones of 11
individuals (four African, seven Asian elephants) were measured with a
pair of callipers to give standardized measurements of the articular
parts. In one Asian and three African elephants, kinematic and
functional analyses were carried out using a digitizer and according to
the helical axis concept. Some peculiarities of healthy and arthrotic
knee joints of elephants were compared with human knees. In contrast to
those of other quadruped mammals, the knee joint of elephants displays
an extended resting position. The femorotibial joint of elephants shows
a high grade of congruency and the menisci are extremely narrow and
thin. The four-bar mechanism of the cruciate ligaments exists also in
the elephant. The main motion of the knee joint is extension-flexion
with a range of motion of 142 degrees . In elephants, arthrotic
alterations of the knee joint can lead to injury or loss of the cranial
(anterior) cruciate ligament
Weissengruber,
G.E., Egger, G.F., Hutchinson, J.R., Groenewald, H.B., Elsasser, L.,
Famini, D., Forstenpointner, G., 2006. The structure of the cushions in
the feet of African elephants (Loxodonta africana)
380. Journal of Anatomy 209, 781-792.
Abstract: The uniquely designed limbs of the African elephant, Loxodonta
africana, support the weight of the largest terrestrial animal. Besides
other morphological peculiarities, the feet are equipped with large
subcutaneous cushions which play an important role in distributing
forces during weight bearing and in storing or absorbing mechanical
forces. Although the cushions have been discussed in the literature and
captive elephants, in particular, are frequently affected by foot
disorders, precise morphological data are sparse. The cushions in the
feet of African elephants were examined by means of standard anatomical
and histological techniques, computed tomography (CT) and magnetic
resonance imaging (MRI). In both the forelimb and the hindlimb a 6th
ray, the prepollex or prehallux, is present. These cartilaginous rods
support the metacarpal or metatarsal compartment of the cushions. None
of the rays touches the ground directly. The cushions consist of sheets
or strands of fibrous connective tissue forming larger
metacarpal/metatarsal and digital compartments and smaller chambers
which were filled with adipose tissue. The compartments are situated
between tarsal, metatarsal, metacarpal bones, proximal phalanges or
other structures of the locomotor apparatus covering the bones palmarly/plantarly
and the thick sole skin. Within the cushions, collagen, reticulin and
elastic fibres are found. In the main parts, vascular supply is good and
numerous nerves course within the entire cushion. Vater-Pacinian
corpuscles are embedded within the collagenous tissue of the cushions
and within the dermis. Meissner corpuscles are found in the dermal
papillae of the foot skin. The micromorphology of elephant feet cushions
resembles that of digital cushions in cattle or of the foot pads in
humans but not that of digital cushions in horses. Besides their
important mechanical properties, foot cushions in elephants seem to be
very sensitive structures
Zuba, J.R.,
Oosterhuis, J.E., Pessier, A.P. The toenail "abscess" in elephants:
treatment options including cryotherapy and pathologic similarities with
equine proliferative pododermatitis (canker). 2006 Proceedings American
Association of Zoo Veterinarians. 187-190. 2006.
Ref Type: Conference Proceeding
Abstract: Foot problems potentially represent the single most important
clinical disease of captive elephants. Predisposing factors include
obesity, lack of exercise, nail or sole overgrowth, improper foot care,
poor hygiene, inappropriate enclosure surfaces, poor conformation,
malnutrition and secondary skeletal disorders such as degenerative joint
disease. Furthermore, factors such as elephant management philosophy,
disposition of elephants, facilities and competency of staff in caring
for elephant feet will contribute significantly to the foot health of
captive animals. It is important to note that these conditions are
rarely reported in free-ranging elephants. The elephant toenail abscess
is characterized grossly by proliferative outgrowth of "crab meat-like"
tissue that may acutely rupture through the surface of the nail wall
and/or adjacent cuticle or sole. True abscess formation with localized
collections of suppurative material is not a consistent clinical
feature. In most cases, the inciting cause of these lesions are
typically not found and are likely due to one or more of the
predisposing factors listed above. Once established, these frustrating
lesions require extensive, intensive and prolonged medical attention.
If not cared for properly, these wounds may progress to phalangeal
osteomyelitis and the need for surgical intervention. Sole abscesses
are equally frustrating and difficult to manage with proposed etiologies
similar to toenail lesions. There are no reports in the literature
describing the pathology of the classic proliferative abscess tissue of
the elephant nail abscess. Although variously interpreted as fibrous or
granulation tissue, the authors are unaware of previous histologic
descriptions of this tissue. Biopsy samples of toenail abscess tissue
from two Asian elephants (Elephas maximus) at the San Diego Wild Animal
Park (SDWAP) consisted of stratified squamous epithelium arranged in
columns resembling horn tubules. The predominant histologic finding was
marked, near diffuse, hydropic degeneration of keratinocytes. There
were multifocal areas of suppurative inflammation with admixed bacterial
colonies. Inflammatory foci comprised only a small portion of the
lesion and were interpreted as the external surfaces of the biopsy with
likely secondary bacterial colonization. Because descriptions of the
normal histology of the elephant toenail could not be located, a grossly
normal toenail from a different Asian elephant was obtained to compare
histologic features with those of the toenail abscesses. Sections
demonstrated formation of the toenail in a manner similar to that of the
hoof of the horse and cattle with tubular, intertubular and laminar
horn. Primary and secondary epidermal laminae were identified.
Proliferative lesions of horn-producing epithelium associated with
ballooning degeneration and inadequate keratinization of keratinocytes,
have been described in horses as equine "canker" and coronary band
dystrophy. Equine canker is most commonly observed in the hind feet of
draft horses and begins in the frog sometimes with extension to the sole
and hoof wall. Grossly, lesions are characterized by soft white
papillary to "cauliflower-like" tissue associated with a foul odor.
Similar to what is noted in elephant foot problems, predisposing factors
for the development of equine canker include poor hygiene or wet
environmental conditions. There is a lack of gross and histologic
description of the normal nail and sole tissue of the elephant and
further investigations are warranted. A review of the anatomy and
histology of the normal equine hoof may provide a basic understanding of
the elephant nail until more specific and detailed elephant information
is available. From our investigation, the authors offer that a more
accurate description of the elephant toenail abscess would be
proliferative pododermatitis, the term synonymous with equine canker. A
more colloquial term such as "elephant canker" may be appropriate, as
well. Canker in the horse is an uncommon but difficult to treat disease
of the hoof. Historically, treatment options for elephant toenail
abscesses include corrective trimming, superficial debridement and
application of topical disinfectants or antibiotics. Others have
constructed innovative sandals to treat and protect the affected sole or
nail with success. The use of regional intravenous perfusion of the
affected limb with antibiotics has also been successful. Since the
elephant nail abscess now appears to be histologically and clinically
comparable to equine canker, this novel characterization of an old
disease may offer unique insight for treatment. In the least, it has
provided our practice with a new list of treatment options and
experienced equine clinicians for consultation who have been managing
patients with a similar disease for many years. One of the Asian
elephants at the SDWAP has had chronic toenail abscesses for over 2 yr.
Radiographs of the affected digits, as reported by others to assess
degree of involvement, have fortunately been negative for evidence of
osteomyelitis. Several bacterial and fungal cultures of deep tissue
biopsies and swabs of affected lesions have resulted in a mixture of
organisms with no consistent single etiologic agent. Biopsies were
found negative for presence of viral DNA (elephant papillomavirus and
herpesvirus) by PCR. Typical elephant foot care at the SDWAP includes
trimming and debriding with hoof knives, foot soaks and topical
antibiotics. Although difficult, attempts are made in keeping the
affected foot clean and dry. Following recommendations for the
treatment of equine canker, we recently implemented the routine use of
cryotherapy in all elephants with proliferative pododermatitis with
improved success in the control and recession of exuberant nail lesions.
The proliferative tissue of the nail is first cleaned then disinfected,
debrided, trimmed with hoof knives and allowed to dry. Modified brass
branding tools with contact surfaces of variable size (2-5 cm diameter)
and shape (round or ovoid) are placed into liquid nitrogen (-196 C) for
several minutes and then placed directly on the cankerous tissue for
30-60 sec. This process is then repeated 4-5 min later, following a
complete thaw of tissue. Within 24 hr, the cryoburned tissue becomes
macerated and necrotic and is readily removed with gentle scrubbing.
Cryotherapy offers the advantage of destroying tissue to a deeper level
than trimming alone and provides hemostasis, as well. Because of
decreased sensation at the cryotherapy treatment site, a memorable
painful event is avoided and the elephant patient is more routinely
accepting of this technique. With the use of hoof knives, we typically
remove 2-3 mm of proliferative tissue before the patient refuses further
treatment, presumably due to discomfort. With cryotherapy, we are able
to remove an additional 3-5 mm of tissue by cell freezing and necrosis.
The result is quicker resolution of cankerous lesions without the need
for aggressive, and potentially painful, interventions. In conclusion,
it appears that elephant nail abscesses can best be described as
proliferative pododermatitis, or canker, as is seen in other species.
Further gross and microscopic descriptions of normal and pathologic nail
or sole lesions are necessary. Routine cryotherapy has shown promise in
the treatment of these chronic, frustrating and potentially devastating
lesions of our captive elephants.
Benz, A.,
Zenker, W., Hildebrandt, T.B., Weissengruber, G.E., Geyer, H. About the
macroscopic and microscopic morphology of elephants' hooves (Elephantidae).
Erkrankungen der Zootiere. Verhandlungsbericht des Internationalen
Symposiums über die Erkrankungen der Zoo- und Wildtiere / International
Symposium on Diseases of Zoo and Wild Animals. 42, 164-166. 2005.
Ref Type: Conference Proceeding
Benz, A. The
elephant's hoof: macroscopic and microscopic morphology of defined
locations under consideration of pathological changes. 2005.
Vetsuisse-Fakultät Universität Zürich.
Ref Type: Thesis/Dissertation
Edwards, H.G.,
Jorge Villar, S.E., Nik Hassan, N.F., Arya, N., O'Connor, S., Charlton,
D.M., 2005. Ancient biodeterioration: an FT-Raman spectroscopic study of
mammoth and elephant ivory
576. Anal. Bioanal. Chem. 383, 713-720.
Abstract: Raman spectra of mammoth ivory specimens have been recorded
using near-infrared excitation, and comparisons made with modern Asian
and African elephant ivories. Whereas the most ancient mammoth ivory
(60-65 ky) showed no evidence for an organic collagen component, more
recent samples of mammoth ivory indicated that some preservation had
occurred, although with biodeterioration of the protein structure
exhibited by the amide I and III bands in the 1200-1700 cm(-1) region of
the Raman spectrum. The consequent difficulties encountered when
applying chemometrics methods to ancient ivory analysis (which are
successful for modern specimens) are noted. In the most ancient mammoth
ivory specimens, which are extensively fragmented, evidence of
mineralization is seen, with the production of gypsum, calcite and
limonite; Raman microscopic analysis of crystalline material inside the
fissures of the mammoth ivory shows the presence of gypsum as well as
cyanobacterial colonisation. The application of Raman spectroscopy to
the nondestructive analysis of archaeological materials in order to gain
information of relevance to their preservation or restoration is
highlighted
Glickman,
S.E., Short, R.V., Renfree, M.B., 2005. Sexual differentiation in three
unconventional mammals: spotted hyenas, elephants and tammar wallabies
566. Horm. Behav. 48, 403-417.
Abstract: The present review explores sexual differentiation in three
non-conventional species: the spotted hyena, the elephant and the tammar
wallaby, selected because of the natural challenges they present for
contemporary understanding of sexual differentiation. According to the
prevailing view of mammalian sexual differentiation, originally proposed
by Alfred Jost, secretion of androgen and anti-Mullerian hormone (AMH)
by the fetal testes during critical stages of development accounts for
the full range of sexually dimorphic urogenital traits observed at
birth. Jost's concept was subsequently expanded to encompass sexual
differentiation of the brain and behavior. Although the central focus of
this review involves urogenital development, we assume that the novel
mechanisms described in this article have potentially significant
implications for sexual differentiation of brain and behavior, a
transposition with precedent in the history of this field. Contrary to
the "specific" requirements of Jost's formulation, female spotted hyenas
and elephants initially develop male-type external genitalia prior to
gonadal differentiation. In addition, the administration of
anti-androgens to pregnant female spotted hyenas does not prevent the
formation of a scrotum, pseudoscrotum, penis or penile clitoris in the
offspring of treated females, although it is not yet clear whether the
creation of masculine genitalia involves other steroids or whether there
is a genetic mechanism bypassing a hormonal mediator. Wallabies, where
sexual differentiation occurs in the pouch after birth, provide the most
conclusive evidence for direct genetic control of sexual dimorphism,
with the scrotum developing only in males and the pouch and mammary
glands only in females, before differentiation of the gonads. The
development of the pouch and mammary gland in females and the scrotum in
males is controlled by genes on the X chromosome. In keeping with the
"expanded" version of Jost's formulation, secretion of androgens by the
fetal testes provides the best current account of a broad array of sex
differences in reproductive morphology and endocrinology of the spotted
hyena, and androgens are essential for development of the prostate and
penis of the wallaby. But the essential circulating androgen in the male
wallaby is 5alpha androstanediol, locally converted in target tissues to
DHT, while in the pregnant female hyena, androstenedione, secreted by
the maternal ovary, is converted by the placenta to testosterone (and
estradiol) and transferred to the developing fetus. Testicular
testosterone certainly seems to be responsible for the behavioral
phenomenon of musth in male elephants. Both spotted hyenas and elephants
display matrilineal social organization, and, in both species, female
genital morphology requires feminine cooperation for successful
copulation. We conclude that not all aspects of sexual differentiation
have been delegated to testicular hormones in these mammals. In
addition, we suggest that research on urogenital development in these
non-traditional species directs attention to processes that may well be
operating during the sexual differentiation of morphology and behavior
in more common laboratory mammals, albeit in less dramatic fashion
Hakeem, A.Y.,
Hof, P.R., Sherwood, C.C., Switzer, R.C., III, Rasmussen, L.E., Allman,
J.M., 2005. Brain of the African elephant (Loxodonta africana):
neuroanatomy from magnetic resonance images. Anat. Rec. A Discov. Mol.
Cell Evol. Biol. 287, 1117-1127.
Abstract: We acquired magnetic resonance images of the brain of an adult
African elephant, Loxodonta africana, in the axial and parasagittal
planes and produced anatomically labeled images. We quantified the
volume of the whole brain (3,886.7 cm3) and of the neocortical and
cerebellar gray and white matter. The white matter-to-gray matter ratio
in the elephant neocortex and cerebellum is in keeping with that
expected for a brain of this size. The ratio of neocortical gray matter
volume to corpus callosum cross-sectional area is similar in the
elephant and human brains (108 and 93.7, respectively), emphasizing the
difference between terrestrial mammals and cetaceans, which have a very
small corpus callosum relative to the volume of neocortical gray matter
(ratio of 181-287 in our sample). Finally, the elephant has an unusually
large and convoluted hippocampus compared to primates and especially to
cetaceans. This may be related to the extremely long social and chemical
memory of elephants
Konishi, S.,
2005. [Jaws of herbivorous mammals]
582. Clin. Calcium 15, 1414-1417.
Abstract: The jaws of herbivorous mammals are characterized by their
large occlusal surface of the molar; high crown of the molar; long
snout; etc. However, elephants, the biggest herbivorous mammal, have
other characteristics. In the evolutionary trends of proboscidean
skulls, concomitant with the increase in tusk size comes on the
enlargement, antero-posterior shortening, dorso-ventral elongation of
the cranium with increasing cheek teeth size. Naturally, the jaw follows
the same evolutionary trends as the cranium
Luikart, K.A., Stover, S.M., 2005.
Chronic sole
ulcerations associated with degenerative bone disease in two Asian
elephants (Elephas maximus). J. Zoo. Wildl. Med. 36, 684-688.
Abstract: Chronic foot lesions and degenerative joint disease are common
causes of morbidity in elephants. Lesions may become intractable and
progressive despite intensive treatment regimens. The forelimbs of two
Asian elephants (Elephas maximus) with chronic nonhealing sole
ulcerations were examined using manual dissection and computed
tomography. Both elephants had abnormal limb conformation that preceded
the development of sole ulcerations. In both cases, sole ulcers were
associated with remodeling and degeneration of underlying bones of the
digits. Conformational abnormalities and altered weight distribution in
these individuals may have induced compensatory bony degeneration and
secondary ulcer formation. Sole ulcerations associated with digital
abnormalities may have a guarded prognosis for resolution, even with
aggressive treatment. Because limb conformational abnormalities could
predispose to or result from chronic digital lesions, elephants with
conformational abnormalities may have increased likelihood of having
chronic sole ulcerations
Mobasheri,
A., Gent, T.C., Womack, M.D., Carter, S.D., Clegg, P.D., Barrett-Jolley,
R., 2005. Quantitative analysis of voltage-gated potassium currents from
primary equine (Equus caballus) and elephant (Loxodonta africana)
articular chondrocytes
618. Am. J. Physiol Regul. Integr. Comp Physiol 289, R172-R180.
Abstract: In this comparative study, we have established in vitro models
of equine and elephant articular chondrocytes, examined their basic
morphology, and characterized the biophysical properties of their
primary voltage-gated potassium channel (Kv) currents. Using whole cell
patch-clamp electrophysiological recording from first-expansion and
first-passage cells, we measured a maximum Kv conductance of 0.15 +/-
0.04 pS/pF (n = 10) in equine chondrocytes, whereas that in elephant
chondrocytes was significantly larger (0.8 +/- 0.4 pS/pF, n = 4, P </=
0.05). Steady-state activation parameters of elephant chondrocytes (V =
-22 +/- 6 mV, k = 11.8 +/- 3 mV, n = 4) were not significantly different
from those of horse chondrocytes (V = -12.5 +/- 4.3 mV, k = 12 +/- 2, n
= 10). This suggests that there would be slightly more resting Kv
activation in elephant chondrocytes than in their equine counterparts.
Kinetic analysis revealed that both horse and elephant chondrocyte Kv
currents had similar activation and inactivation parameters.
Pharmacological investigation of equine chondrocyte Kv currents showed
them to be powerfully inhibited by the potassium channel blockers
tetraethylammonium and 4-aminopyridine but not by dendrotoxin-I.
Immunohistochemical studies using polyclonal antibodies to Kv1.1-Kv1.5
provided evidence for expression of Kv1.4 in equine chondrocytes. This
is the first electrophysiological study of equine or elephant
chondrocytes. The data support the notion that voltage-gated potassium
channels play an important role in regulating the membrane potential of
articular chondrocytes and will prove useful in future modeling of
electromechanotransduction of fully differentiated articular
chondrocytes in these and other species
Natiello, M.,
Lewis, P., Samuelson, D., 2005. Comparative anatomy of the ciliary body
of the West Indian manatee (Trichechus manatus) and selected species.
Vet. Ophthalmol. 8, 375-385.
Abstract: OBJECTIVE: To examine the anatomy of the ciliary body in the
West Indian manatee (Trichechus manatus), paying close attention to its
vascularization and to compare to those of its distant relative, the
African elephant (Loxodonta africana), the amphibious hippopotamus
(Hippopotamus amphibius) and the aquatic short-finned pilot whale (Globicephala
macrorhynchus). PROCEDURE: Specimens from each species were preserved in
10% buffered formalin, and observed stereomicroscopically before being
embedded in paraffin, sectioned and stained by Masson trichrome,
hematoxylin and eosin, and periodic acid-Schiff for light microscopic
evaluation. RESULTS: The network of blood vessels in the ciliary
processes of the West Indian manatee appear to have an intricate
pattern, especially with regard to venous outflow. Those of the elephant
are slightly less complex, while those of the hippopotamus and whale
have different vascular patterns within the ciliary body. Musculature
within the ciliary body is absent within the manatee and pilot whale.
CONCLUSIONS: In general, there appears to be a direct relationship
between the increased development of vasculature and the loss of
musculature within the ciliary bodies of the aquatic and amphibious
mammals presently studied. Specifically, the ciliary body of the West
Indian manatee has a comparatively unique construction, especially with
regard to its vasculature.
Perez-Barberia, F.J., Gordon, I.J., 2005.
Gregariousness increases brain size in ungulates
586. Oecologia. 145, 41-52.
Abstract: The brain's main function is to organise the physiological and
behavioural responses to environmental and social challenges in order to
keep the organism alive. Here, we studied the effects that
gregariousness (as a measurement of sociality), dietary habits,
gestation length and sex have on brain size of extant ungulates. The
analysis controlled for the effects of phylogeny and for random
variability implicit in the data set. We tested the following groups of
hypotheses: (1) Social brain hypothesis-gregarious species are more
likely to have larger brains than non-gregarious species because the
former are subjected to demanding and complex social interactions; (2)
Ecological hypothesis-dietary habits impose challenging cognitive tasks
associated with finding and manipulating food (foraging strategy); (3)
Developmental hypotheses (a) energy strategy: selection for larger
brains operates, primarily, on maternal metabolic turnover (i.e.
gestation length) in relation to food quality because the majority of
the brain's growth takes place in utero, and finally (b) sex hypothesis:
females are expected to have larger brains than males, relative to body
size, because of the differential growth rates of the soma and brain
between the sexes. We found that, after adjusting for body mass,
gregariousness and gestation length explained most of the variation in
brain mass across the ungulate species studied. Larger species had
larger brains; gregarious species and those with longer gestation
lengths, relative to body mass, had larger brains than non-gregarious
species and those with shorter gestation lengths. The effect of diet was
negligible and subrogated by gestation length, and sex had no
significant effect on brain size. The ultimate cause that could have
triggered the co-evolution between gestation length and brain size
remains unclear
Pichardo, M.,
2005. Taxonomic revision of Central Mexican mammoths in Paleoindian
sites
522. Anthropol. Anz. 63, 409-413.
Abstract: Central Mexican mammoth species taxonomy has been based on the
quotient Molar length/Number of dental plates, which sorted three
species, Mammuthus imperator, columbi and ?jeffersonii. New evidence
from skull morphology sorts only two subspecies, M. columbi columbi and
M. columbi felicis as being present during Paleoindian time
Raubenheimer,
E.J., Ngwenya, S.P., 2005. The role of ivory in the survival of the
African elephant
510. SADJ. 60, 426, 430.
Abstract: The unique chequered pattern of polished ivory has created a
perverted commercial demand for elephant tusks. The morphologic basis of
the pattern, which makes ivory a sought after product for the
manufacturing of works of art, is discussed. Chemical analyses of ivory
holds great potential in tracing the source of illegally harvested tusks
and exposing poorly managed elephant sanctuaries. The impact of
uncontrolled ivory hunting on the population genetics of the African
elephant is briefly reviewed
Roth, G.,
Dicke, U., 2005. Evolution of the brain and intelligence
612. Trends Cogn Sci. 9, 250-257.
Abstract: Intelligence has evolved many times independently among
vertebrates. Primates, elephants and cetaceans are assumed to be more
intelligent than 'lower' mammals, the great apes and humans more than
monkeys, and humans more than the great apes. Brain properties assumed
to be relevant for intelligence are the (absolute or relative) size of
the brain, cortex, prefrontal cortex and degree of encephalization.
However, factors that correlate better with intelligence are the number
of cortical neurons and conduction velocity, as the basis for
information-processing capacity. Humans have more cortical neurons than
other mammals, although only marginally more than whales and elephants.
The outstanding intelligence of humans appears to result from a
combination and enhancement of properties found in non-human primates,
such as theory of mind, imitation and language, rather than from
'unique' properties
Shoshani, J.,
Tassy, P., 2005. Advances in proboscidean taxonomy & classification,
anatomy & physiology, and ecology & behavior. Quaternary International
126-128, 5-20.
Abstract: With the addition of 13 new taxa, we recognized 175 species
and subspecies of proboscideans, classified in 42 genera and 10
families. The three extant species are: forest African elephant (Loxodonta
cyclotis), bush African elephant (L. africana), and Asian
elephant (Elephas maximus, with three subspecies). Rigorous
analysis of characters published or awaiting publication is imperative
for better understanding of the cladistic relationships among currently
recognized proboscideans. Here we focus on ''aquatic ancestry'' of
Proboscidea, interordinal relationships within Placentalia, proboscidean
taxonomy in general and South American in particular, anatomy and
physiology and some ecological considerations. New taxa above the family
level include sister taxa Mammutida and Elephantida, and
Plesielephantiformes as a sister taxon to Elephantiformes. Neontological
research is currently under way on the hyoid apparatus, lungs, brain,
hearing, ecology and behavior. Topics for future research include:
phylogenetic positions of anthracobunids, Moeritherium,
tetralophodont gomphotheres, Stegolophodon and Stegodon,
and intra-familial relationships among Loxodonta, Elephas
and Mammuthus, and continuing studies on encephalization
quotient. Certain anatomical features and functions (e.g., the hyoid
apparatus that helps in food procurement, in production of infrasonic
sounds, and in storing water to be used in time of stress) evolved about
25 million years ago, in time for diversification into new niches when
grasses appeared in the landscape.
Surovell, T.,
Waguespack, N., Brantingham, P.J., 2005. Global archaeological evidence
for proboscidean overkill
616. Proc. Natl. Acad. Sci. U. S. A 102, 6231-6236.
Abstract: One million years ago, proboscideans occupied most of Africa,
Europe, Asia, and the Americas. Today, wild elephants are only found in
portions of sub-Saharan Africa and South Asia. Although the causes of
global Pleistocene extinctions in the order Proboscidea remain
unresolved, the most common explanations involve climatic change and/or
human hunting. In this report, we test the overkill and climate-change
hypotheses by using global archaeological spatiotemporal patterning in
proboscidean kill/scavenge sites. Spanning approximately 1.8 million
years, the archaeological record of human subsistence exploitation of
proboscideans is preferentially located on the edges of the human
geographic range. This finding is commensurate with global overkill,
suggesting that prehistoric human range expansion resulted in localized
extinction events. In the present and the past, proboscideans have
survived in refugia that are largely inaccessible to human populations
Weissengruber, G.E., Egerbacher, M., Forstenpointner, G., 2005.
Structure and
innervation of the tusk pulp in the African elephant (Loxodonta
africana)
617. Journal of Anatomy 206, 387-393.
Abstract: African elephants (Loxodonta africana) use their tusks for
digging, carrying and behavioural display. Their healing ability
following traumatic injury is enormous. Pain experience caused by dentin
or pulp damage of tusks seems to be negligible in elephants. In this
study we examined the pulp tissue and the nerve distribution using
histology, electron microscopy and immunhistochemistry. The results
demonstrate that the pulp comprises two differently structured regions.
Randomly orientated collagen fibres characterize a cone-like part lying
rostral to the foramen apicis dentis. Numerous nerve fibres and Ruffini
endings are found within this cone. Rostral to the cone, delicate
collagen fibres and large vessels are orientated longitudinally. The
rostral two-thirds of the pulp are highly vascularized, whereas nerve
fibres are sparse. Vessel and nerve fibre distribution and the structure
of connective tissue possibly play important roles in healing and in the
obviously limited pain experience after tusk injuries and pulp
alteration. The presence of Ruffini endings is most likely related to
the use of tusks as tools
Zack, S.P.,
Penkrot, T.A., Bloch, J.I., Rose, K.D., 2005. Affinities of 'hyopsodontids'
to elephant shrews and a Holarctic origin of Afrotheria
622. Nature 434, 497-501.
Abstract: Macroscelideans (elephant shrews or sengis) are small-bodied
(25-540 g), cursorial (running) and saltatorial (jumping), insectivorous
and omnivorous placental mammals represented by at least 15 extant
African species classified in four genera. Macroscelidea is one of
several morphologically diverse but predominantly African placental
orders classified in the superorder Afrotheria by molecular
phylogeneticists. The distribution of modern afrotheres, in combination
with a basal position for Afrotheria within Placentalia and molecular
divergence-time estimates, has been used to link placental
diversification with the mid-Cretaceous separation of South America and
Africa. Morphological phylogenetic analyses do not support Afrotheria
and the fossil record favours a northern origin of Placentalia. Here we
describe fossil postcrania that provide evidence for a close
relationship between North American Palaeocene-Eocene apheliscine 'hyopsodontid'
'condylarths' (early ungulates or hoofed mammals) and extant
Macroscelidea. Apheliscine postcranial morphology is consistent with a
relationship to other ungulate-like afrotheres (Hyracoidea, Proboscidea)
but does not provide support for a monophyletic Afrotheria. As the
oldest record of an afrothere clade, identification of macroscelidean
relatives in the North American Palaeocene argues against an African
origin for Afrotheria, weakening support for linking placental
diversification to the break-up of Gondwana
Boellaard,
J.W., Schlote, W., Hofer, W., 2004. Species-specific ultrastructure of
neuronal lipofuscin in hippocampus and neocortex of subhuman mammals and
humans
630. Ultrastruct. Pathol. 28, 341-351.
Abstract: Lipofuscin represents an integral part of neurons and glial
cells in mammals and in submammalian species. It is a special lysosomal
organelle, takes part of cellular metabolism, and is a structural
expression of catabolic pathways. Species-specific differences of
lipofuscin indicate metabolic differences of the relevant neurons. The
authors have studied the ultrastructure of neuronal lipofuscin in the
hippocampus and cerebral neocortex of dogs, horses, cows, elephants,
rats, mice, apes, and humans to answer the question of species-specific
differences of this organelle. Paraffin sections of formalin-fixed
material were investigated by hematoxylin-eosin and PAS staining, by
fluorescence microscopy for autofluorescence, with a laser scanning
confocal microscope and by electron microscopy. In the animals studied
and in humans the lipofuscin displayed, in addition to the general
trilaminar substructure, species-specific appearances. No differences
were found in the lipofuscin structure between neocortical and
hippocampal neurons of the separate animal species. In contrast, in
humans, neurons of the hippocampus showed a particular lipofuscin
structure, not only different from the neocortical one, but also with
differences between CA1 and CA3/4 sectors. Interestingly, in apes a
transitional situation was found with slight differences between
neocortical and hippocampal lipofuscin, especially in the rhesus monkey.
This peculiarity was corroborated by the distribution of special
pentilaminar linear structures in the lipofuscin pigment in all animals,
only sparsely in the rhesus monkey and not in humans. The results
indicate that lipofuscin ultrastructure of neocortical and hippocampal
neurons is species specific and that lipofuscin in the human hippocampal
neurons displays structures characteristic of man differing from the
neocortical neuronal lipofuscin. The neuronal lipofuscin of apes,
especially of the rhesus monkey displays structures in between humans
and lower mammals. Nothing is known about the functional significance of
these findings. They may indicate metabolic and/or functional
characteristics of the relevant neurons
Boy, S.C.,
Steenkamp, G., 2004. Neural innervation of the tusk pulp of the African
elephant (Loxodonta africana)
730. Veterinary Record 154, 372-374.
Brown, J.L.,
Walker, S.L., Moeller, T., 2004. Comparative endocrinology of cycling
and non-cycling Asian (Elephas maximus) and African (Loxodonta africana)
elephants
729. Gen. Comp Endocrinol. 136, 360-370.
Abstract: Up to 14% of Asian and 29% of African elephants in captivity
are not cycling normally or exhibit irregular cycles based on progestin
profiles. To determine if ovarian acyclicity is related to other
disruptions in endocrine activity, serum pituitary, thyroid, adrenal,
and ovarian hormones in weekly samples collected for 6-25 months were
compared between normal cycling (n=22 each species) and non-cycling (n=6
Asian; n=30 African) elephants. A subset of cycling females (n=4 Asian,
7 African) also were blood sampled daily during the follicular phase to
characterize the peri-ovulatory period. In normal cycling females, two
leutinizing hormone (LH) surges were observed 3 weeks apart during a
normal follicular phase, with the second inducing ovulation (ovLH).
Serum FSH concentrations were highest at the beginning of the non-luteal
phase, declining to nadir concentrations within 4 days of the ovLH
surge. FSH remained low until after the ovLH surge and then increased
during the luteal phase. A species difference was noted in prolactin
secretion. In the African elephant, prolactin was increased during the
follicular phase, but in Asian elephants concentrations remained stable
throughout the cycle. Patterns of thyroid hormones (thyroid-stimulating
hormone, TSH; free and total thyroxine, T4; free and total
triiodothyronine, T3) and cortisol secretion were not affected by
estrous cycle stage or season in cycling elephants. In non-cycling
elephants, there were no fluctuating patterns of LH, FSH, or prolactin
secretion. Overall mean concentrations of all hormones were similar to
those in cycling animals, with the exception of FSH, prolactin, and
estradiol. Mean serum FSH concentrations were lower due to females not
exhibiting normal cyclic increases, whereas serum estradiol was higher
overall in most acyclic females. Prolactin concentrations were
significantly increased in 11 of 30 non-cycling females, all of which
were African elephants. In sum, while there were no consistent endocrine
anomalies associated with ovarian acyclicity, hyperprolactinemia may be
one cause of ovarian dysfunction. The finding of elevated estrogens in
some acyclic females also deserves further investigation, especially
determining how it relates to reproductive tract pathologies
Carter, A.M.,
Enders, A.C., Kunzle, H., Oduor-Okelo, D., Vogel, P., 2004. Placentation
in species of phylogenetic importance: the Afrotheria
705. Anim Reprod. Sci. 82-83, 35-48.
Abstract: Afrotheria, one of four mammalian superorders, comprises
elephants, sea cows, hyraxes, aardvark, elephant shrews, tenrecs and
golden moles. Their placentas either form an equatorial band or are
discoid in shape. The interhemal region, separating fetal and maternal
blood, is endotheliochorial in elephants, aardvark and possibly the sea
cows, but hemochorial in the remaining orders. There is a secondary
epitheliochorial placenta in elephant shrews while a similar structure
in tenrecs erodes maternal tissues. Specialized hemophagous regions are
a striking characteristic of some of these placentas yet absent in
hyraxes, elephant shrews, and golden moles. It is possible that the
common ancestor of the Afrotheria had an endotheliochorial placenta.
Establishment of a hemochorial condition, as seen in rock hyraxes,
elephant shrews, tenrecs, and golden moles, would be a more recent
development. The elephant, manatee, and aardvark all have
circumferential placentas. Thus the formation of a discoid placenta with
a more or less extensive secondary placenta in elephant shrews and
tenrecs would also be a derived state
Debruyne, R.,
2004. [Contribution of molecular phylogeny and morphometrics to the
systematics of African elephants]
590. J. Soc. Biol. 198, 335-342.
Abstract: African elephants are conventionally classified as a single
species: Loxodonta africana (Blumenbach 1797). However, the discovery in
1900 of a smaller form of the African elephant, spread throughout the
equatorial belt of this land, has given rise to a debate over the
relevance of a second species of elephant in Africa. The twentieth
century has not provided any definite answer to this question. Actually,
recent molecular analyses have sustained this issue by advocating either
a division of forest elephants into a valid species, or their inclusion
as a subspecies of L. africana. Our work initiated at the National
Museum of Natural History of Paris provides new molecular
(mitochondrial) and morphological (and morphometrical) evidence making
it possible to propose a comprehensive phylogenetic hypothesis. It
appears that there is no conclusive argument to keep forest elephants (cyclotis
form) and savannah elephants (africana form) apart in two distinct
species. A high level of mitochondrial introgression between the two
forms, as well as a continuum in the morphology of the skulls of the two
morphotypes rather suggests that, despite an ancient division, these two
taxa freely interbreed wherever their ranges intersect. We thus adopt a
conservative systematic position in considering these two forms as two
subspecies, respectively: L. africana africana, the savannah elephant,
and L. africana cyclotis, the forest elephant. We finally discuss the
conservation topic in the light of this systematic framework
Enders, A.C.,
Carter, A.M., 2004. What can comparative studies of placental structure
tell us?--A review
739. Placenta 25 Suppl A , S3-S9.
Abstract: The diversity of placental structures in Eutherian mammals is
such that drawing generalizations from the definitive forms is
problematic. There are always areas of reduced interhaemal distance
whether the placenta is epitheliochorial, synepitheliochorial,
endotheliochorial or haemochorial. However, the thinning may be achieved
by different means. The presence of a haemophagous area as an iron
transport facilitator is generally associated with endotheliochorial
placentae but is also found in sheep and goats (synepitheliochorial) and
in tenrecs and hyaenas (haemochorial). Although similar chorioallantoic
placentae are found within families, structure begins to diverge at the
ordinal level and there is little correlation at the supraordinal level
of phylogeny. Differences in formation and function of the yolk sac
provide additional variation. There would appear to be considerable
adaptive pressure for development or retention of the haemochorial type
of chorioallantoic placenta. This type of placenta has several possible
drawbacks including more ready passage of fetal cells to the maternal
organism and, should the haemochorial condition be achieved early,
oxidative stress. At any rate no animal larger than the human and
gorilla has this type of placenta. The endotheliochorial condition is
found in animals as large as the bears, manatee and elephants. In
addition to the ungulates, the epitheliochorial condition is present in
the largest animals with the longest gestation periods, the whales.
Considering the length of time since the early stages of mammalian
evolution, it is probable that few unmodified structural features are
present in any currently surviving mammal. Nevertheless, more complete
studies of divergent types of mammalian placenta should help our
understanding of mammalian interrelationships as well as placental
function
Gobbel, L.,
Fischer, M.S., Smith, T.D., Wible, J.R., Bhatnagar, K.P., 2004. The
vomeronasal organ and associated structures of the fetal African
elephant, Loxodonta africana (Proboscidea, Elephantidae). Acta Zoologica
85, 41-52.
Abstract: The vomeronasal organ (VNO) is a chemosensory structure of the
nasal septum found in most tetrapods. Although potential behavioural
correlates of VNO function have been shown in two of the three elephant
species, its morphology in Loxodonta africana has not been studied. The
development of the VNO and its associated structures in the African
elephant are described in detail using serially sectioned material from
fetal stages. The results show that many components of the VNO complex
(e.g. neuroepithelium, receptor-free epithelium, vomeronasal nerve,
paravomeronasal ganglia, blood vessels, vomeronasal cartilage) are well
developed even in a 154-day-old fetus, in which the VNO opens directly
into the oral cavity with only a minute duct present. However, the
vomeronasal glands and their ducts associated with the VNO were
developed only in the 210-day-old fetus. Notably, in this fetus, the
vomeronasal-nasopalatine duct system had acquired a pathway similar to
that described in the adult Asian elephant; the VNOs open into the oral
cavity via the large palatal parts of the nasopalatine ducts, which are
lined by a stratified squamous epithelium. The paired palatal ducts
initially coursed anteriorly at an angle of 45degrees from the oral
recess and/or the oral cavity mucosa, and merged into the vomeronasal
duct. This study confirms the unique characteristics of the elephant VNO,
such as its large size, the folded epithelium of the VNO tube, and the
dorsomedial position of the neuroepithelium. The palatal position and
exclusive communication of the VNO with the oral cavity, as well as the
partial reduction of the nasopalatine duct, might be re
Hatfield, J.R.,
Samuelson, D.A., Lewis, P.A., Chisholm, M., 2004. Structure and
presumptive function of the iridocorneal angle of the West Indian
manatee (Trichechus manatus), short-finned pilot whale (Globicephala
macrorhynchus), hippopotamus (Hippopotamus amphibius), and African
elephant (Loxodonta africana). Vet Ophthalmol. 6, 35-43.
Abstract: The iridocorneal angles of prepared eyes from the West Indian
manatee, short-finned pilot whale, hippopotamus and African elephant
were examined and compared using light microscopy. The manatee and pilot
whale demonstrated capacity for a large amount of aqueous outflow,
probably as part of a system compensating for lack of ciliary
musculature, and possibly also related to environmental changes
associated with life at varying depths. The elephant angle displayed
many characteristics of large herbivores, but was found to have
relatively low capacity for aqueous outflow via both primary and
secondary routes. The hippopotamus shared characteristics with both
land- and water-dwelling mammals; uveoscleral aqueous outflow may be
substantial as in the marine mammals, but the angular aqueous plexus was
less extensive and a robust pectinate ligament was present. The angles
varied greatly in size and composition among the four species, and most
structures were found to be uniquely suited to the habitat of each
animal. Department of Small Animal Clinical Sciences, College of
Veterinary Medicine, University of Florida, Gainesville, Florida 32610,
USA.
Hoffmann, J.N.,
Montag, A.G., Dominy, N.J., 2004. Meissner corpuscles and somatosensory
acuity: the prehensile appendages of primates and elephants
669. Anat. Rec. A Discov. Mol. Cell Evol. Biol. 281, 1138-1147.
Abstract: Meissner corpuscles (MCs) are specialized mechanoreceptors
located exclusively in the papillae of glabrous skin. They are confined
largely to cutaneous pads of the extremities and respond to transient,
phasic, or vibratory stimuli. Though absent in most eutherian taxa, MCs
are reported in all primates studied, being most developed in modern
humans. The location of MCs between the internal ridges of the epidermis
indicates they are well situated to detect friction or deformation at
the external surface. Accordingly, MCs are hypothesized to provide
primates generally with an enhanced tactile perception. However, the
selective pressures favoring greater somatosensory acuity in primates
are seldom considered. Interestingly, primate digital dexterity varies
greatly. In general, dexterity improves with the extent to which
foraging requires food manipulation or textural evaluation. This
observation implies that MC density could vary accordingly. Here we
report on the density of MCs in five anthropoid taxa selected to
represent diverse dietary regimes. Results show that greater MC density
correlates with the extent to which primates are frugivorous; however,
locomotor and/or phylogenetic effects cannot be discounted
Lazar, J.,
Rasmussen, L.E., Greenwood, D.R., Bang, I.S., Prestwich, G.D., 2004.
Elephant albumin: a multipurpose pheromone shuttle
691. Chem. Biol. 11, 1093-1100.
Abstract: (Z)-7-dodecenyl acetate (Z7-12:Ac) is present in the urine of
female Asian elephants (Elephas maximus) approaching ovulation and
functions as a female-to-male sex pheromone. Here we show that a
significant fraction of the pheromone in the urine is bound to a
protein, elephant serum albumin (ESA), and provide evidence for key
physiological functions of urinary ESA. Our biochemical and behavioral
experiments suggest a three-fold role of ESA in pheromone signaling: (1)
transporting Z7-12:Ac from serum into urine; (2) extending the presence
of the pheromone in the environment without hampering detection; and (3)
targeting pheromone delivery to chemosensory organs through localized
release of the ligand induced by a pH change. The exploitation of
albumin in pheromone transport clearly distinguishes the elephant from
other mammals studied, and complements the uniqueness of elephant
anatomy, physiology, and behavior
Leal, W.S.,
2004. Pheromone unwrapping by pH flip-flopping
692. Chem. Biol. 11, 1029-1031.
Abstract: The Asian elephant utilizes the same sex pheromone as a number
of moth species, (Z)-7-dodecen-1-yl acetate encapsulated in a
serum-derived albumin. The chemical signal is emitted in the urine and
received in the mucus of the trunk. The unwrapping of the package is pH
mediated
Repin, V.E.,
Taranov, O.S., Ryabchikova, Tikhonov, A.N., Pugachev, V.G., 2004.
Sebaceous glands of the woolly mammoth, Mammothus primigenius Blum:
histological evidence
651. Dokl. Biol. Sci. 398, 382-384.
Weissengruber,
G.E., Forstenpointner, G., 2004. Musculature of the crus and pes of the
African elephant (Loxodonta africana): insight into semiplantigrade limb
architecture
689. Anat. Embryol. (Berl) 208, 451-461.
Abstract: The limbs of elephants are designed to support the weight of
the largest terrestrial animal, and they display unique morphological
peculiarities among mammals. In this article we provide a new and
detailed anatomical description of the muscles of the lower hindlimb in
African elephants (Loxodonta africana), and we place our observations
into a comparative anatomical as well as a functional morphological
context. At the cranial aspect of the shank (crus) and the foot (pes),
the flexors of the tarsal joint and the extensors of the toes form a
flat muscular plate covering the skeletal elements. Caudal to the tibia
and the fibula the Musculus (M.) soleus is strongly developed, whereas
the M. gastrocnemius and the M. flexor digitorum superficialis are thin.
Small flexors, adductors, and abductors of the toes are present. The M.
tibialis caudalis as well as the Mm. fibularis longus and brevis mainly
support the tarsal joint. The design of the muscular structures matches
the specific requirements of heavy-weight bearing as well as of
proboscidean limb posture and locomotion patterns
2003.
Healthcare, Breeding and Management of Asian Elephants. Project
Elephant. Govt. of India, New Delhi.
Allen, W.R.,
Mathias, S., Wooding, F.B., van Aarde, R.J., 2003. Placentation in the
African elephant (Loxodonta africana): II morphological changes in the
uterus and placenta throughout gestation. Placenta 24, 598-617.
Abstract: The gross and microscopic development of the zonary
endotheliochorial placenta in the African elephant was studied in 22
gravid uteri that ranged in
gestational stage from 0.5 to 20.6 months. The conceptus only ever
occupies one horn of the uterus and is associated with 2-5 large corpora
lutea that persist in the ipsilateral ovary throughout gestation.
Initially, the trophoblast in the equatorial region of the conceptus
completely replaces the lumenal epithelium of the endometrium to which
it is apposed. Blunt upgrowths of endometrial stroma then develop, each
closely invested by trophoblast, and containing the capillaries that
will vascularize this maternal component of the resulting placental
band. With advancing gestation the lamellate stromal upgrowths increase
markedly in length and become much thinner, thereby bringing the
trophoblast into intimate contact with the endothelium of the maternal
capillaries. They also become folded or pleated to increase the total
area of intimate feto-maternal contact. At the lateral edges of the
placental band the lamellae bend over towards the endometrium to form a
blind cleft. Leakage of blood into this area creates haemophagous zones
in which phenotypically specialized trophoblast cells phagocytose the
blood components. The presence of large resorbing blood clots and
circumferential scars in the uteri of three post parturient animals
initiated the hypothesis that, when the standing elephant gives birth at
term, the passage of the 120 kg fetus through the vagina may wrench the
placenta off the endometrium by severing its very narrow maternal
placental hilus. The resulting intrauterine haemorrhage may then play a
role in preventing further conception for around 2 years.Department of
Clinical Veterinary Medicine Equine Fertility Unit, University of
Cambridge, Mertoun Paddocks,Woodditton Road, Suffolk CB8 9BH, Newmarket,
UK. vetart@aht.org.uk
Barasa, A.,
2003. Morphology and structure of the nictitating membrane cartilage in
mammals. Morphologie 87, 5-12.
Abstract: In 30 species of Mammals of varying body size (from rat to
elephant), the form, dimensions and structure of the cartilage of the
third eyelid were studied. The cartilage is a thin lamina concave in its
corneal side, usually elongated in the oro-aboral direction. In the most
species studied the outline of the cartilage may be inscribed in a
triangle with a oral base, a dorsal margin, a ventral margin and an
aboral apex. A study of stained sections revealed, in more than half of
species, the presence of elastic fibres in the aboral part of cartilage;
these fibres are particularly numerous, but non uniformly distributed,
in the Equidae, lion and Suidae. Departement de Morphophysiologie
Veterinaire, Rue L. de Vinci 44, 10095 Grugliasco, Italie.
Bhattacharyya, B.K., 2003. Some reproductive traits of elephants. In:
Das, D. (Ed.), Healthcare, Breeding and Management of Asian Elephants.
Project Elephant. Govt. of India, New Delhi, pp. 37-41.
Clauss, M.,
Frey, R., Kiefer, B., Lechner-Doll, M., Loehlein, W., Polster, C.,
Rossner, G.E., Streich, W.J., 2003. The maximum attainable body size of
herbivorous mammals: morphophysiological constraints on foregut, and
adaptations of hindgut fermenters. Oecologia 136, 14-27.
Abstract: An oft-cited nutritional advantage of large body size is that
larger animals have lower relative energy requirements and that, due to
their increased gastrointestinal tract (GIT) capacity, they achieve
longer ingesta passage rates, which allows them to use forage of lower
quality. However, the fermentation of plant material cannot be optimized
endlessly; there is a time when plant fibre is totally fermented, and
another when energy losses due to methanogenic bacteria become punitive.
Therefore, very large herbivores would need to evolve adaptations for a
comparative acceleration of ingesta passage. To our knowledge, this
phenomenon has not been emphasized in the literature to date. We propose
that, among the extant herbivores, elephants, with their comparatively
fast passage rate and low digestibility coefficients, are indicators of
a trend that allowed even larger hindgut fermenting mammals to exist.
The limited existing anatomical data on large hindgut fermenters
suggests that both a relative shortening of the GIT, an increase in GIT
diameter, and a reduced caecum might contribute to relatively faster
ingesta passage; however, more anatomical data is needed to verify these
hypotheses. The digestive physiology of large foregut fermenters
presents a unique problem: ruminant-and nonruminant-forestomachs were
designed to delay ingesta passage, and they limit food intake as a side
effect. Therefore, with increasing body size and increasing absolute
energy requirements, their relative capacity has to increase in order to
compensate for this intake limitation. It seems that the foregut
fermenting ungulates did not evolve species in which the intake-limiting
effect of the foregut could be reduced, e.g. by special bypass
structures, and hence this digestive model imposed an intrinsic body
size limit. This limit will be lower the more the natural diet enhances
the ingesta retention and hence the intake-limiting effect. Therefore,
due to the mechanical characteristics of grass, grazing ruminants cannot
become as big as the largest browsing ruminant. Ruminants are not absent
from the very large body size classes because their digestive physiology
offers no particular advantage, but because their digestive physiology
itself intrinsically imposes a body size limit. We suggest that the
decreasing ability for colonic water absorption in large grazing
ruminants and the largest extant foregut fermenter, the hippopotamus,
are an indication of this limit, and are the outcome of the competition
of organs for the available space within the abdominal cavity. Our
hypotheses are supported by the fossil record on extinct ruminant/tylopod
species which did not, with the possible exception of the Sivatheriinae,
surpass extant species in maximum body size. In contrast to foregut
fermentation, the GIT design of hindgut fermenters allows adaptations
for relative passage acceleration, which explains why very large extinct
mammalian herbivores are thought to have been hindgut fermenters.
Institute of Animal Physiology, Physiological Chemistry and Animal
Nutrition, Ludwig-Maximilians-University, Veterinaerstrasse 13, 80539,
Munich, Germany. clauss@tiph.vetmed.uni-muenchen.de
Das, D.,
2003. Breeding, reproduction and conservation strategies in Asian
elephants. In: Das, D. (Ed.), Healthcare, Breeding and Management of
Asian Elephants. Project Elephant. Govt. of India, New Delhi, pp. 45-57.
Dutta, D.,
2003. Physiology of elephant. In: Das, D. (Ed.), Healthcare, Breeding
and Management of Asian Elephants. Project Elephant. Govt. of India, New
Delhi, pp. 17-22.
Hutchinson,
J.R., Famini, D., Lair, R., Kram, R., 2003. Biomechanics: Are
fast-moving elephants really running? Nature 422, 493-494.
Isaza, R.,
Behnke, B.J., Bailey, J.K., McDonough, P., Gonzalez, N.C., Poole, D.C.,
2003. Arterial blood gas control in the upright versus recumbent Asian
elephant. Respir Physiolo Neurobiol 134, 169-176.
Abstract: In the elephant, there is concern that lateral recumbency (LR)
impairs respiratory muscle and lung function resulting in clinically
significant arterial hypoxemia. Using healthy adult female Asian
elephants (Elephas maximus, n=6), the hypothesis was tested that, given
the O2 binding characteristics of elephant blood, substantial
reductions in arterial O2 pressure PaO2 in LR
could be tolerated without lowering arterial O2 content
appreciably. Fifteen minutes of LR decreased PaO2 from
103+/-2 (upright, U) to 77+/-4 mmHg (P<0.05) and hemoglobin O2
saturation (U, 97.8+/-0.1, LR, 95.3+/-0.5%, P<0.05). However, due to a
recumbency-induced hemoconcentration, arterial O2 content
was unchanged (U, 18.2+/-2.4, LR, 18.3+/-2.1 ml O2 per 100
ml). In addition, there was a mild hyperventilation in LR that reduced
arterial CO2 pressure (PCO2) from 39.4+/-0.3 to
37.1+/-1.0 mmHg (P<0.05). These data indicate that the Asian elephant
can endure at least short periods of LR without lowering arterial O2
content.
Kalita, S.N.,
Sarma, M., 2003. Anatomy of elephant: some important features. In: Das,
D. (Ed.), Healthcare, Breeding and Management of Asian Elephants.
Project Elephant. Govt. of India, New Delhi, pp. 10-16.
Nalla, R.K.,
Kinney, J.H., Ritchie, R.O., 2003. Effect of orientation on the in vitro
fracture toughness of dentin: the role of toughening mechanisms.
Biomaterials 24, 3955-3968.
Abstract: Toughening mechanisms based on the presence of collagen
fibrils have long been proposed for mineralized biological tissues like
bone and dentin; however, no direct evidence for their precise role has
ever been provided. Furthermore, although the anisotropy of mechanical
properties of dentin with respect to orientation has been suggested in
the literature, accurate measurements to support the effect of
orientation on the fracture toughness of dentin are not available. To
address these issues, the in vitro fracture toughness of dentin,
extracted from elephant tusk, has been characterized using fatigue-precracked
compact-tension specimens tested in Hank's balanced salt solution at
ambient temperature, with fracture paths perpendicular and parallel to
the tubule orientations (and orientations in between) specifically being
evaluated. It was found that the fracture toughness was lower where
cracking occurred in the plane of the collagen fibers, as compared to
crack paths perpendicular to the fibers. The origins of this effect on
the toughness of dentin are discussed primarily in terms of the salient
toughening mechanisms active in this material; specifically, the role of
crack bridging, both from uncracked ligaments and by individual collagen
fibrils, is considered. Estimates for the contributions from each of
these mechanisms are provided from theoretical models available in the
literature. Materials Sciences Division, Lawrence Berkeley National
Laboratory, Department of Materials Science and Engineering, University
of California, Berkeley, CA 94720, USA.
Pothiwong,
W., Kamonrat, P., Uthaichotiwan, P., 2003. A morphological study and
diagnotic ultrasonography of Asian elephant kidney. Thai Journal of
Veterinary Medicine 33, 79-88.
Rajaram, A.,
Krishnamurthy, V., 2003. Elephant temporal gland ultrastructure and
androgen secretion during musth. Current Science 85, 1467-1471.
Abstract: We have investigated the ultrastructure of the temporal gland
of the Asian elephant (Elephas maximus) in the musth condition. We find
that the organelles are highly evolved for the production of the
androgen, testosterone which is reported to be very high in the Asian
male elephant in full musth. The mitochondria bear cristae which are
profuse and tubular, and occur along with many Golgi bodies. There is
hypertrophy of smooth endoplasmic reticulum. All the structures involved
in the production of androgen, as in the Leydig cell or the cells of the
adrenal cortex, are thus found in abundance. Cellular structures also
seem singularly evolved for the secretion of androgen and its
degradation products.
Steenkamp,
G., 2003. Oral biology and disorders of tusked mammals. Veterinary Clin
North Am Exot Anim Pract. 6, 689-725.
Abstract: Tusked mammals can be terrestrial or aquatic. Many of these
magnificent animals are kept in captivity all over the world. Functions
of tusks vary as much as the species in which they occur. Dental
anomalies and disorders of tusks and the rest of the dentition in these
mammals were discussed, with an emphasis on the elephant. The tusk
anatomy, with its large, conically-shaped pulp, makes it an ideal tooth
for partial pulpectomy treatment in trauma cases where the pulp is
exposed. Surgical techniques for tusks have been developed and were
discussed. Oral tumors occur, but are rare.Department of Companion
Animal Clinical Studies, Faculty of Veterinary Science, University of
Pretoria, Private Bag X04, Onderstepoort 0010, South Africa. steenkamp@op.up.ac.za
West, J.B.,
Fu, Z., Gaeth, A.P., Short, R.V., 2003. Fetal lung development in the
elephant reflects the adaptations required for snorkeling in adult life.
Respir Physiol Neurobiol 138, 325-333.
Abstract: The adult elephant is unique among mammals in that the pleural
membranes are thickened and the pleural cavity is obliterated by
connective tissue. It has been suggested that this peculiar anatomy
developed because the animal can snorkel at depth, and this behavior
subjects the microvessels in the parietal pleura to a very large
transmural pressure. To investigate the development of the parietal
pleura, the thickness of the endothoracic fascia (ET) was measured in
four fetal African elephants of approximate gestational age 111-130
days, and the appearances were compared with those in human, rabbit, rat
and mouse fetuses of approximately the same stage of lung organogenesis.
The mean thicknesses of ET in the elephant, human, rabbit, rat and mouse
were 403, 53, 29, 27 and 37 microm, respectively. This very early
development of a thick parietal pleura in the elephant fetus is
consistent with the hypothesis of a long history of snorkeling in the
elephant's putative aquatic ancestors. Department of Medicine,
University of California San Diego, 9500 Gilman Drive, La Jolla, CA
92093-0623, USA. jwest@ucsd.edu
Yappert, M.C.,
Rujoi, M., Borchman, D., Vorobyov, I., Estrada, R., 2003. Glycero-
versus sphingo-phospholipids: correlations with human and non-human
mammalian lens growth. Exp Eye Res 76, 725-734.
Abstract: The human lens differs from other mammalian lenses in its very
slow growth and unusual phospholipid composition of its cell membranes.
Dihydrosphingomyelins (DHSMs) make up about half of all phospholipids in
adult human fiber membranes. In all other membranes, sphingomyelins(SMs)
with a trans double bond in their backbone, are prevalent. In our quest
to understand the biological implications of such elevated DHSM levels,
we analyzed membranes from various regions of human, elephant, giraffe,
polar bear, pig and cow lenses. The levels of DHSMs were minor in
non-human lens membranes. A strong correlation was observed between
growth rate and relative contents of phosphatidylcholines(PCs) in
epithelia and outer cortical fibers. Sphingomyelins became increasingly
predominant in differentiated fibers and this increase was age
dependent. Indeed, nuclear fiber membranes of aged non-human mammals
were composed, almost exclusively, of (SMs). Although human lens
membranes followed comparable compositional trends, the magnitude of the
changes was much smaller. We postulate that the high relative contents
of DHSMs provide a biochemically inert matrix in which only small
amounts of PCs and SMs and their metabolites, known to promote and
arrest growth, respectively, are present. This compositional difference
is proposed to contribute to the slow multiplication and elongation of
human lens cells. Department of Chemistry, College of Arts and Sciences,
University of Louisville, Louisville, KY 40292, USA. mcyapper@louisville.edu
Allen, W.R.,
Mathias, S.S., Wooding, F.B., Skidmore, J.A., van Aarde, R.J., 2002.
Placentation in the African elephant, Loxodonta africana. I.
Endocrinological aspects. Reprod Suppl 60, 105-116.
Abstract: Placental and fetal tissues were recovered from the uteri of
59 pregnant elephant that ranged in estimated age from day 18 to month
21 of gestation. Incubation of placenta and fetal gonad, alone or in
combination, with tritium-labelled cholesterol, pregnenolone and
androstenedione failed to yield any labelled progestagens or oestrogens
from placenta, but did produce small amounts of labelled progesterone
and 5alpha-dihydroprogesterone from fetal gonad. Immunochemical staining
of tissues with four antisera specific for enzymes involved in the
steroidogenic pathway revealed no staining in sections of placenta but
positive labelling for P450 side chain cleavage enzyme (SCC450) and
3beta-hydroxysteroid dehydrogenase (3beta-HSD) of the interstitial cells
that comprise the bulk of the enlarged fetal gonads during the second
half of gestation. Saline extracts of placental tissue showed no
activity in three different gonadotrophin assays. In view of this
endocrinological inactivity in the zonary elephant placenta and the
probable reliance on maternal luteal sources of progestagens for
maintenance of the pregnant state, the argument is advanced that
uncomplicated abortion would probably follow a single administration of
a PGF analogue given at any stage of pregnancy. If so, the treatment
might constitute an efficacious method for controlling population
increases in elephants maintained in enclosed game parks in Africa.
Chandrasekharan, K., 2002. Elephant - an overview. Journal of Indian
Veterinary Association Kerala 7, 8-11.
Cheeran, J.V.,
2002. Elephant facts. Journal of Indian Veterinary Association Kerala 7,
12-14.
Endo, H.,
Akihisa, N., Sasaki, M., Yamamoto, M., Arishima, K., 2002. The renal
structure in an Asian elephant (Elephas maximus). Anat Histol Embryol 31,
269-272.
Abstract: The renal structure of a female Asian elephant (Elephas
maximus) was observed in both macroscopic and light microscopic levels.
The left kidney was elongated-ellipse in shape, whereas the right
appeared round. The left kidney was 31 cm in cranio-caudal length, 21 cm
in medio-lateral length, and 2950 g in weight. The right kidney was 34
cm in cranio-caudal length, 22 cm in medio-lateral length, and 3250 g in
weight. The external appearance showed the six separated renal lobes in
both sides of the kidney. The four pairs of the lobes were fused in the
deepest region in both sides of kidney, so we considered it as an
incompletely lobated kidney in this species. We observed the proximal
and distal urinary tubules in histological sections. Many renal
corpuscles consisted of the glomerulus and Bowman's capsule. Many
mesangial cells and some podocytes were confirmed in each glomerulus;
however, Bowman's capsules were larger than those in other mammalian
species.
Johnson,
E.W., Rasmussen, L., 2002. Morphological characteristics of the
vomeronasal organ of the newborn Asian elephant (Elephas maximus).
Anatomical Record 267, 252-259.
Abstract: The 6-week-old Asian elephant (Elephas maximus) has a
well-documented precocious flehmen response to pheromones, suggesting
that the pheromone-detecting vomeronasal organ (VNO) is functional very
early in the life of this species. To further document this, the VNOs of
two newborn elephants were examined in situ and analyzed by light
microscopy (LM) to ascertain their structural maturity at birth. A
tubular, cartilage-encased VNO was located along the anterior base of
each side of the nasal septum. Its rostral end was connected to a duct
to the roof of the mouth; the caudal end was attached to a well-defined
vomeronasal nerve projecting toward the brain. LM revealed distinctive
differences in the mucosae bordering the horseshoe-shaped lumen: a
concave, sensory mucosa, and a convex, nonsensory mucosa. Small groups
of receptor neurons were observed among ciliated columnar cells in the
sensory epithelium. Numerous unmyelinated nerve bundles and blood
vessels filled the underlying lamina propria (LP) and a small section of
the vomeronasal nerve was conspicuous at one edge. The nonsensory mucosa
manifested a thinner epithelium that principally consisted of ciliated
columnar cells, some of which showed a granular cytoplasm, and a
conspicuous row of basal cells. The LP was replete with acinar glands
and ducts that opened into the lumen. This study shows that the VNO of
the newborn elephant has reached an advanced stage of structural
maturity, closely resembling that of the adult. Its composition supports
the view that flehmen at 6 weeks delivers pheromones to a functional VNO.
Kim, C.S.,
Won, C.K., Cho, G.H., Cho, K.W., Park, J.S., Rho, G.J., 2002. A case of
fused thoracic vertebrae, and lumbar vertebrae, sacrum and ilium of
African elephant (Loxodonta africana). Korean Journal of Veterinary
Research 42, 131-136.
Kumar, G.A.,
Ghosh, K.N.A., Sreekumaran, T., Chandrasekharan, K., 2002. Reproduction
in elephants. Journal of Indian Veterinary Association Kerala 7,
38-40, 48-48.
Langman,
V.A., Rowe, M., Maloney, M., McQuire, R., Carrington, R. Obligatory
heterothermia a story of elephant radiators. Proceedings of the Elephant
Managers Association Conference. Journal of Experimental Biology, Lond.
22, 136. 2002.
Ref Type: Conference Proceeding
Rees, P.A.,
2002. Asian elephants (Elephas maximus) dust bathe in response to an
increase in environmental temperature. Journal of Thermal Biology 27,
353-358.
Abstract: (1) A captive herd of Asian elephants (Elephas maximus)
exhibited dusting behaviour when the maximum daily temperature exceeded
approximately 13°C, and dusting frequency increased directly with the
environmental temperature. (2) Individual animals showed variation in
dusting frequency but this was not related to body mass, suggesting that
the function of dusting is not primarily thermoregulatory. (3)
Synchronisation in the timing of dusting behaviour within the herd
suggests that it may have a function in the maintenance of social
cohesion. (4) The function of dusting behaviour could not be determined
from the data presented, but it may be involved in skin care,
protection from insects or other parasites, temperature control,
protection from radiation or some combination of these.
Saseendran,
P.C., Anil, K.S., Nair, A., Radhakrishnan, K., Prasad, A., 2002.
Elephants and work. Journal of Indian Veterinary Association Kerala 7,
41, 48-48.
Soltysiak,
Z., Barcikowska, M., Nieman, S., 2002. Specification patterns of amyloid-beta
deposits in old fish, reptile, bird and several old mammal brains.
Medycyna \Weterynaryjna 58, 74-76.
Abstract: The study was conducted to demonstrate whether there are
amyloid-beta deposits in old fish, reptiles, birds and some mammals. The
thick brain sections were stained with cresyl violet, Congo red,
tioflavin S and by immunocytochemistry using mAb 4G8. Amyloid-beta
deposits were not found in old fish, reptile and bird brains. Amyloid-beta
was found in old mammal brains in three forms: parenchymal amyloidosis,
congophilic angiopathy and diffuse amyloid deposits. Three types of
plaque were found in old mammal brain cortexes: diffuse, primitive, and
classic (neuritic). The neuritic plaque alveas consisted of three
components: degenerating neurites, amyloid, and reactive cells.
Parenchymal amyloidosis and congophilic angiopathy were found only in
five mammal brains, two from wolf, two from fox and one from elephant
brain. Congophilic angiopathy was discovered in all investigated
mammals.
Sreekumar,
K.P., 2002. Physiological features of Indian elephant. Journal of Indian
Veterinary Association Kerala 7, 35-36.
West, J.B.,
2002. Why Doesn't the Elephant Have a Pleural Space? News Physiol Sci 17,
47-50.
Abstract: The elephant is the only mammal whose pleural space is
obliterated by connective tissue. This has been known for 300 years but
never explained. The elephant is also the only animal that can snorkel
at depth. The resulting pressure differences require changes in the
pleural membranes and pleural space.
Witter, K., Matulova, P., Misek, I., 2002.
The lateral
enamel lamina--component of tooth primordia in selected mammalian
species. Connect Tissue Res 42, 134-137.
Abstract: The lateral enamel lamina (LEL) is a part of the enamel organ,
which is probably not involved in tooth formation. It represents,
besides the "stalk" of the tooth primordium, a second interconnection
between enamel organ and oral epithelium or vestibular lamina. We
detected the LEL in the sheep (Ovis aries), the dolphin (Stenella
attenuata), and the vole (Microtus agrestis) by light microscopy and
computer-aided three-dimensional reconstruction. The LEL could be found
in cap to bell stage tooth primordia, most clearly in slowly developing
tooth germs. LEL-like structures have been furthermore described or
depicted in tooth germs of the mouse, the elk (Alces alces), the dugong
(Dugong dugong), the elephant (Loxodonta africana), and the human.
Probably it is a part of all mammalian tooth primordia that undergoes
regression during morphogenesis of the enamel organ. As a reducing
structure, it should be considered in studies of tooth development.
Ball, R.L.
Ultrasound Evaluation of the Pleura Space and Associated Connective
Tissue in the Asian Elephant (Elephas maximus). A Research Update
on Elephants and Rhinos; Proceedings of the International Elephant and
Rhino Research Symposium, Vienna, June 7-11, 2001. 245. 2001. Vienna,
Austria, Schuling Verlag. 2001.
Ref Type: Conference Proceeding
Cozzi, B., Spagnoli, S., Bruno, L., 2001.
An overview
of the central nervous system of the elephant through a critical
appraisal of the literature published in the XIX and XX centuries. Brain
Res Bull 54, 219-227.
Abstract: The two species of elephants (Indian: Elephas maximus and
African: Loxodonta africana) possess the largest brain among land
mammals. Due to its size, the elephant brain is discussed in virtually
every paper dealing with the evolution of the central nervous system of
mammals and comparative brain size. Studies on the social habits of
elephants also deal with the skills and the "intelligence" and brain
size of these species. Yet most of the descriptions and conclusions
reported in comparative studies rely on second-hand data derived from
investigations performed several decades before, often dating as far
back as the XIX century. Furthermore, many of the original papers
actually describing gross and detailed features of the brain of
elephants are either no longer available, are written in languages other
than English, or are difficult to trace. The present study gives a short
description of the anatomy of the central nervous system of elephants,
with special attention to its distinctive features, reports all
available literature on the subject, and briefly discusses its origins
and rationale.
Dehnhard, M.,
Hildebrand, T., Rohleder, M., Strauss, G., Meyer, H.H.D., Goritz, F.,
2001. Application of an enzyme-immunoassay (EIA) for rapid screening of
5alpha-pregnane-3,20-dione (DHP) in blood plasma of the Asian elephant,
Elephas maximus. Berliner und Munchener Tierarztliche Wochenschrift. 114,
161-165.
Abstract: Populations of African (Loxodonta africana) and Asian
elephants (Elephas maximus) in zoos and safari parks are at risk due to
their low reproductive success. To extend the limited knowledge of their
reproductive physiology, easy and practical methods for the analysis of
relevant reproductive hormones must be developed to support assisted
reproduction, for instance. Blood samples from 2 nonpregnant and 2
pregnant Asian elephants were used in the following study. For the
measurement of 5alpha-pregnane-3,20-dione (DHP), the predominant ovarian
gestagen in both species, an enzyme-immunoassay (EIA) based on
commercial reagents was applied. Advantages of this EIA are the small
volume of plasma needed for evaluation (5 µl) and the possibility of
direct processing without an extraction stage. The lower limit of
detection was 0.16 ng/ml, mean recovery was 101% and the mean
coefficients of variation were 7.3 (intra-assay) and 9.9% (inter-assay).
In the Asian elephants, DHP levels reached 15 ng/ml during the luteal
phase and 21 ng/ml during pregnancy. Oestrous cycle lengths based on the
lowest DHP concentrations varied from 12 to 20 weeks (mean of 15.4±2.3).
In two Asian elephant cows, a calf was stillborn. Thereafter, ovarian
activity in the animals resumed after approximately 8 and 13 weeks,
respectively. In one animal, estradiol implants for hormonal
contraception caused a down regulation of ovarian function as
demonstrated by an irregular pattern of DHP secretion over a period of
48 weeks. It is proposed that the direct DHP-EIA is a suitable method
for reproductive monitoring in elephants, as it can be easily
established in laboratories.
Endo, H., Hayashi, Y., Komiya, T., Narushima, E., Sasaki, M., 2001.
Muscle
architecture of the elongated nose in the Asian elephant (Elephas
maximus). Journal of Veterinary Medical Science 63, 533-537.
Abstract: The architecture of the M. caninus in the elongated nose was
examined in the Asian elephant (Elephas maximus). The following
complicated musculature of the M. caninus was observed in the proximal
and distal regions of the nose: (1) Proximal region: In the superficial
layer, the longitudinal bundles are confirmed in the dorsal part, and
the obliquely-oriented ones in the ventral part. In the middle layer,
some bundles run ventro-distally, while other ones represent
longitudinally-oriented running. The deep layer consists of complicated
architecture of many bundles. Some muscle bundles run medio-laterally,
while the others extend proximo-distally in this space. (2) Distal
region: In the dorsal part of the M. caninus, the bundles run at
deep-superficial direction, while in the ventral part the bundles are
longitudinally arranged. The bundles run at lateral direction near the
septum of the nasal conduits. The N. facialis and N. infraorbitalis send
many branches in the lateral area of the M. caninus in the trunk. This
muscle architecture of multi-oriented bundles and well-developed
innervation to them suggest that they enable the elongated nose to act
as a refined manipulator in the Asian elephant.
Ganslober, U.
Behavioural Ecology, Social Relationships, Life History and Evolutionary
Constraints in Megaherbivores. A Research Update on Elephants and
Rhinos; Proceedings of the International Elephant and Rhino Research
Symposium, Vienna, June 7-11, 2001. 26-31. 2001. Vienna, Austria,
Schuling Verlag. 2001.
Ref Type: Conference Proceeding
Hinke, A.,
Wipplinger, J. A Case of Molar Anomalie in an Asian Elephant (Elephas
maximus). A Research Update on Elephants and Rhinos; Proceedings of
the International Elephant and Rhino Research Symposium, Vienna, June
7-11, 2001. 264. 2001. Vienna, Austria, Schuling Verlag. 2001.
Ref Type: Conference Proceeding
Lamps, L.W.,
Smoller, B.R., Rasmussen, L.E., Slade, B.E., Fritsch, G., Goodwin, T.E.,
2001. Characterization of interdigital glands in the Asian elephant
(Elephas maximus). Research in Veterinary Science 71, 197-200.
Abstract: In the Asian elephant, wetness akin to perspiration is
commonly observed on the cuticles and interdigital areas of the feet;
this observation has lead to speculation regarding the existence of an
interdigital gland. Our goal was to search for interdigital glands and
characterize them morphologically, histochemically, and
immunohistochemically. Necropsy samples of interdigital areas from two
Asian elephants were obtained. Multiple sections were fixed and
processed routinely, then stained with hematoxylin/eosin and
differential mucin stains. Immunohistochemistry was also performed for
cytokeratins 8 and 10. Interdigital glands resembling human eccrine
glands were detected deep within the reticular dermis. Histochemical
staining indicated neutral mucopolysaccharides and nonsulphated acid
mucopolysaccharides in glandular secretions, and the glandular
epithelium also showed immunoreactivity to cytokeratins 8 and 10. Both
the histochemical and immunohistochemical staining patterns are
analogous to human eccrine structures. This study shows with certainty
that Asian elephants possess sweat glands as they are defined
histologically.
Phillips, P.K.,
Heath, J.E., 2001. Heat loss in Dumbo: a theoretical approach. Heat loss
in Dumbo: a theoretical approach 26, 117-120.
Abstract: A flat plate model was used to calculate heat loss from the
pinnae of the animated elephant Dumbo. In conditions of high wind
velocity and large
gradients, Dumbo could potentially dissipate more heat than he produces.
This suggests that he may need the large ears to help lose the excess
heat produced while flying.
Ramsay, E.,
Henry, R., 2001. Anatomy of the Elephant Foot. In: Csuti, B., Sargent,
E.L., Bechert, U.S. (Eds.), The Elephant's Foot. Iowa State University
Press, Ames IA, USA, pp. 9-12.
Abstract: While elephants have played an important role in human ecology
throughout recorded history, their anatomy has been the subject of
relatively few studies, and these studies considered only a limited
number of specimens. This is especially true for the elephants' feet,
despite the common occurrence of foot disease in elephants (Evans 1961,
Mikota et al. 1994). One study that surveyed North American captive
elephants found that 50 percent had experience foot problems (Mikota et
al. 1994). Despite their phylogenetic differences, the components of
Asian (Elephas maximus) and African (Loxodonta africana)
elephants feet are remarkably similar. The major differences are the
shape of the rear foot and the number of phalanges and toenails. This
is not to say that the feet of the two species are the same. The
differences in their wild habitats and the more common occurrence of
foot lesions in captive Asian elephants suggest that the biology of the
two species' feet are quite different. The following describes
anatomical characteristics common to both species unless otherwise
identified.
Singer, M.A.,
2001. Of mice and men and elephants: metabolic rate sets glomerular
filtration rate. Am J Kidney Dis 37, 164-178.
Abstract: Allometric scaling deals with the functional consequences of
changes in size or scale among geometrically dissimilar animals (ie,
animals differing in proportions). For adult mammals ranging in size and
proportion from mouse to elephant, the data describe an interdependent
set of functions consisting of metabolism (measured as metabolic rate),
glomerular filtration rate (GFR), effective renal plasma flow, excretion
of nitrogenous waste products, cardiac output, and pulmonary
function-related variables. Within this set of functions, evidence
indicates that metabolic rate is the primary process. One important
design feature is given by the ratio of GFR to metabolic rate. Because
this ratio is independent of size, it can be generalized to all mammals
in this series. The numeric value of this ratio gives the optimal GFR
for each unit of metabolic rate. A simple hypothesis is proposed:
metabolic rate, the primary process, sets GFR. This relationship is
unidirectional. A decrease in GFR, for example, caused by nephron loss,
should not lead to a change in metabolic rate. This hypothesis was
tested in four natural experiments: human growth and development,
thyroid dysfunction, chronic renal failure, and hibernation. The results
are consistent with this hypothesis.
West, J.B.,
2001. Snorkel breathing in the elephant explains the unique anatomy of
its pleura. Respiratory Physiology 126, 1-8.
Abstract: It has been known for over 300 years that the anatomy of the
elephant lung is unique among mammals in that the pleural cavity is
obliterated by connective tissue. However no satisfactory explanation
has been advanced. Recent studies suggest that the elephant has an
aquatic ancestry and the trunk may have developed for snorkeling. In
addition, the modern day elephant is the only mammal that can remain
submerged far below the surface of the water while snorkeling. The
resulting differences of pressures within the thorax mean that the small
blood vessels of the pleura are in great danger of rupturing or causing
severe edema. The same distribution of pressures occurs when the animal
raises water inside its trunk prior to drinking although in this case
the pressure differences are relatively short-lived. Evolution has
provided a remarkable solution to this problem by replacing the normally
delicate parietal and visceral pleurae by dense connective tissue, and
separating the two pleurae by loose connective tissue to allow some
sliding movement.
Crossley,
D.A., 2000. Elephant tusks: where are the nerves? J. Vet. Dent. 17,
37.
Fritsch, G.,
Göritz, F., Hermes, R., Jewgenow, K., Maltzan, J., Hildebrandt, T.B.,
2000. Physiology of sexual maturity in male elephants. Reprod Dom Anim
35, 26.
Kitiyanant,
Y., Schmidt, M.J., Pavasuthipaisit, K., 2000. Evaluation of sperm
acrosome reaction in the Asiatic elephant. Theriogenology 53,
887-896.
Abstract: This study focuses on the effect of chemicals on acrosome
reaction in elephant spermatozoa. Semen was collected at the Washington
Park Zoo in Portland, Oregon, from an 11-yr-old Asian elephant by
artificial vagina (7 ejaculates) and transported to Mahidol University
in Bangkok in extender at 4 to 5 degrees C within 24 to 28 h. A total of
500 x 10(6) sperm/mL was used for the control and for each of the 4
treatment groups: 1) cAMP (0.1 mM); 2) caffeine (0.1 mM); 3)
Penicillamine hypotaurine and epinephrine, PHE (penicillamine 2 mM,
hypotaurine 1 mM, epinephrine 1 mM); and 4) heparin (10 microg/mL) at 39
degrees C for 2 h. Aliquots were removed and the sperm viability,
abnormal morphology, and acrosome status were evaluated by triple stain
technique. Transmission electron microscopy (TEM) was used to observe
changes of the sperm head membrane in all treatment groups. Trypan blue
reliably stained dead spermatozoa, while rose Bengal stained only the
spermatozoa with intact acrosomes. The concentration of dead sperm cells
was similar in the 4 groups. The percentages of live acrosome-reacted
spermatozoa in the control and in groups treated with caffeine, PHE,
cAMP and heparin were 19.5 +/- 4.3, 38.1 +/- 4.0, 34.8 +/- 3.7, 29.8 +/-
0.8 and 28.0 +/- 4.2, respectively. The acrosome reaction rate was
higher in the treatment groups than in the control (P<0.05). Caffeine
and PHE caused significantly higher acrosome reaction of the sperm head
than cAMP or heparin (P<0.05). The electron micrographs showed that the
acrosome reaction occurred by the presence of apical vesiculation. The
results indicated that 1) the triple stain technique allowed for
evaluation of both viability and acrosome reaction simultaneously in
elephant spermatozoa,2) acrosome reaction occurred at a high rate in all
3 treatment groups. 3) the effects of caffeine and PHE were
significantly higher (P<0.05) than of cAMP and heparin, and 4) the data
obtained from the triple stain technique corresponded to those from TEM.
Luikart, K.
Anatomy of the Elephant Forefoot. Elephants: Cultural, Behavioral, and
Ecological Perspectives; Program and Abstracts of the Workshop. 14-15.
2000. Davis, CA. 2000.
Ref Type: Conference Proceeding
Malik, M.R.,
Shrivastav, A.B., Jain, N.K., Vaish, R., 2000. Morphometry of kidney of
elephant. Indian Journal of Veterinary Anatomy 12 , 101-102.
Malik, M.R.,
Shrivastava, A.B., Jain, V.K., Rakhi, V., 2000. Lobar pattern of kidneys
of elephant. Indian Journal of Veterinary Anatomy 12, 18-22.
Malik, M.R.,
Shrivastava, A.B., Jain, V.K., Rakhi, V., 2000. Biometry of the cerebral
ventricles of elephant. Indian Journal of Veterinary Anatomy 12,
110-112.
Malik, M.R.,
Shrivastav, A.B., Jain, V.K., Rakhi, V., 2000. A note on encephalometry
of Asian elephant. Indian Journal of Veterinary Anatomy 12,
103-104.
Raubenheimer,
E.J., 2000. Early development of the tush and the tusk of the African
elephant (Loxodonta africana). Arch Oral Biol 45, 983-986.
Schmitt, D.L.,
Pace, L.W. Multiple Congenital Cardiac Anomalies in a Newborn Asian
Elephant (Elephas maximus). Proceedings of the Elephant Managers
Association Conference, Oct 6-9,2000 Syracuse, NY. 13-14. 2000. 2000.
Ref Type: Conference Proceeding
Abstract: Cardiac anomalies in humans occur in about 1% of human births.
Most are a developmental disorder of the vascular trunk and septum of
the heart, which result in reduced blood circulation to periphery. This
report of a cardiac anomaly in a neonatal elephant is first to the
author's knowledge. A congenital defect known as tetrology of Fallot is
described in a male Asian elephant who lived for 9 hours following
birth.
Singer, M.A.,
Morton, A.R., 2000. Mouse to elephant: biological scaling and Kt/V. Am J
Kidney Dis 36, 306-309.
Abstract: The construct Kt/V is used by the nephrology community in
prescribing dialysis dose. The concerns that have been raised as to what
value of V to use in the calculation of Kt/V touch on the more central
question of whether filtration rate should be normalized by a parameter
other than V. Within the animal kingdom, a number of physiological
variables scale to body size according to an equation of the form Y =
YoMb, where Yo is a constant, M is body mass, and b is a scaling
exponent. Glomerular filtration rate (GFR) in mammals weighing from 30 g
to 503 kg scales to body weight with an exponent of 0.77. Hence, GFR per
unit body weight (or Kt/V) decreases significantly with increasing body
size. Metabolic rate also scales to body size in a wide range of mammals
according to the same general equation and with a scaling exponent of
0.75. Because GFR and metabolic rate scale to body mass with virtually
the same exponent, a ratio of the two yields a constant independent of
body size. We propose that the ratio (filtration rate/metabolic rate)
replace Kt/V. Such a ratio would underscore the linkage between
filtration rate (and dialysis therapy) and the metabolic demands of the
body.
Valli, V.E.,
Jacobs, R.M., 2000. Structure and function of the hemopoietic system.
In: Feldman, B., Zinkl, J.G., Jain, N.C. (Eds.), Schalm's Veterinary
Hematology. Lippinicott, Williams & Wilkins, Baltimore, Maryland, USA,
pp. 225-239.
Victor, S.,
Nayak, V.M., 2000. Evolutionary anticipation of the human heart. Ann R
Coll Surg Engl 82, 297-302.
Abstract: We have studied the comparative anatomy of hearts from fish,
frog, turtle, snake, crocodile, birds (duck, chicken, quail), mammals
(elephant, dolphin, sheep, goat, ox, baboon, wallaby, mouse, rabbit,
possum, echidna) and man. The findings were analysed with respect to the
mechanism of evolution of the heart.
Weissengruber,
G.E., Kubber-Heiss, A., Forstenpointner, G., Riccaboni, P., 2000. On the
morphology of the temporal gland (Glandula temporalis) in the African
elephant (Loxodonta africana). Wiener Tierarztliche Monatsschrift 87,
303-308.
1999. Equine
Medicine and Surgery. Mosby, St. Louis MO USA.
Fagan, D.A.,
Benirschke, K., Simon, J.H., Roocroft, A., 1999. Elephant dental pulp
tissue: where are the nerves? J Vet Dent 16, 169-172.
Abstract: Dental pulp tissue from three elephants was examined
histologically with hematoxylin and eosin and s-100 protein stains. In
all specimens, normal pulp was found with the exception that no nerve
fibers (myelinated or non-myelinated) were demonstrable in any of the
numerous sections prepared.
Gaeth, A.P.,
Short, R.V., Renfree, M.B., 1999. The developing renal, reproductive,
and respiratory systems of the African elephant suggest an aquatic
ancestry. Proc Natl Acad Sci U S A 96, 5555-5558.
Abstract: The early embryology of the elephant has never been studied
before. We have obtained a rare series of African elephant (Loxodonta
africana) embryos and fetuses ranging in weight from 0.04 to 18.5 g,
estimated gestational ages 58-166 days (duration of gestation is
approximately 660 days). Nephrostomes, a feature of aquatic vertebrates,
were found in the mesonephric kidneys at all stages of development
whereas they have never been recorded in the mesonephric kidneys of
other viviparous mammals. The trunk was well developed even in the
earliest fetus. The testes were intra-abdominal, and there was no
evidence of a gubernaculum, pampiniform plexus, processus vaginalis, or
a scrotum, confirming that the elephant, like the dugong, is one of the
few primary testicond mammals. The paleontological evidence suggests
that the elephant's ancestors were aquatic, and recent immunological and
molecular evidence shows an extremely close affinity between present-day
elephants and the aquatic Sirenia (dugong and manatees). The evidence
from our embryological study of the elephant also suggests that it
evolved from an aquatic mammal.
Rasmussen, L.E.L., Perrin, T.E., 1999.
Physiological
correlates of musth: lipid metabolites and chemical composition of
exudates. Physiology and Behavior 67, 539-549.
Abstract: Physiological changes related to lipid metabolism, behaviour
and chemicals released in body exudates were studied during musth in the
Asian elephant (Elephas maximus) as a case study. During musth, changes
in serum testosterone and triglyceride concentrations followed similar
patterns, with the former increasing sooner than the latter. Deviant
behaviour increased during changing androgen levels. The observed high
concentrations of testosterone were positively and significantly
correlated with increased triglycerides. Lipase activity elevated
significantly immediately before and after musth. Blood pH increased
significantly in alkalinity. Urine and temporal gland secretions
released variable amounts of compounds, some of which may be chemical
signals. During musth, temporal gland and urinary exudates demonstrated
increased acetone and other ketones indicative of lipid metabolic
alterations. Large quantities of nonmethane hydrocarbons, especially
2-butanone, were released from the seemingly dry orifice of the temporal
gland before the start of over musth and before maximum blood elevations
were observed; isoprene release was similar. However, maximal acetone
levels occurred simultaneously in blood, temporal gland secretions, and
urine. Metabolically, musth is a series of interwoven, changing stages
of increasing and decreasing hormones and lipid-related constituents.
Released chemicals can be quantitatively related to these internal
physiological events; some observed behaviours appear to result from
altered chemical signals.
Silver, W.,
1999. Chemesthesis: The burning questions. Chemosense 2.
Abou-Madi,
N., Kollias, G.V., Sturmer, A.T., Hackett, R.P. Umbilical herniorrhaphy
in a juvenile Asian elephant (Elephas maximus). Proceedings AAZV
and AAWV Joint Conference. 212-216. 1998.
Ref Type: Conference Proceeding
Godagama, W.K.,
Wemmer, C., Ratnasooriya, W.D., 1998. The body condition of Sri Lankan
domesticated elephants (Elephas maximus maximus). Ceylon Journal of
Science, Biological Sciences 26, 1-5.
Abstract: The objective of this study was to evaluate the body condition
of domesticated elephants in Sri Lanka using an index based upon visual
assessment and numerical scoring of 6 criteria (temporal depression,
scapula, thoracic region, flank area, lumbar vertebrae and pelvic bone)
resulting in a scale of 0-11. The study was conducted between 1 April
1993 and 1 April 1994 in 13 administrative districts using 140
domesticated elephants. The mean body condition index of the elephants
was 6.95±0.26 points. Males had significantly lower body condition index
(6.63±0.22 points) than females (7.3±0.21 points) and there was no
significant correlation between age and body condition index. The index
was not significantly different between elephants which were owned by
private individuals or temples and dewales and maintained by mahouts or
their owners.
Godagama, W.K.,
Wemmer, C., Ratnasooriya, W.D., 1998. Spinal conformation of
domesticated Sri Lankan elephants (Elephas maximus maximus). Ceylon
Journal of Science, Biological Sciences 26, 7-11.
Abstract: The study investigated whether the 5 spinal conformations
previously described for the Burmese elephant (Elephas maximus
birmanicus) are also present in the Sri Lankan elephant. 140
domesticated elephants were examined according to Gale's
five-description system. The 5 spinal conformation types described for
the Burmese elephant are also present in the Sri Lankan elephant. Out of
the 140 elephants, 23 (16%) had Type 1, 48 (34%) had Type 2, 5 (4%) had
Type 3, 50 (36%) had Type 4 and 14 (10%) had Type 5 spinal conformation.
There was a significant variation in the spinal conformation of male and
female elephants.
Patil, V.A.,
Bhamburkar, V.R., Dalvi, R.S., Banubakode, S.B., Kale, M.A., 1998.
Morphometrical study of pelvis in some animals. Journal of Bombay
Veterinary College 6, 45-46.
Abstract: The morphometric study of the pelvis in buffaloes, cattle,
goats, horses, pigs, dogs, panthers, sambar and elephants was carried
out. The pelvic index, obturator foramen index, greater sciatic notch
index and lesser sciatic notch index were calculated. It is concluded
that these indices are useful in species differentiation.
Rasmussen,
L.E.L., 1998. Chemical communication: An integral part of functional
Asian elephant (Elephas maximus) society. Ecoscience 5,
410-426.
Abstract: The matriarchally organized Asian elephant society is
characterized by long-term stability and continuity. Flux within this
society results from changing ecological conditions and the dynamics of
its population. Its structure is influenced by age composition and
physiological states within the female herd and by impinging influences
of the peripheral males, especially during reproductive times. Recent
behavioral studies of captive populations have substantiated older field
studies and have demonstrated that chemical signals play a significant
role in elephant society. Chemical investigations, based on previously
substantiated behavioral interactions, have identified specific
compounds or combinations of compounds in elephant emissions (especially
urine, temporal gland secretions and breath) that retain bioactivity
throughout chemical extractions and playback experiments, based on
behavioral and/or chemosensory responses. Chemosensory neuroreceptive
systems in Asian elephants are reviewed, as well as behavioral and
chemosensory effects of whole exudate chemical signals on lifestyles,
especially related to mating. Several discrete and composite chemical
signals have been deciphered in elephants, one of which is a
preovulatory female-to-male pheromone, (Z)-7-dodecen-1-yl acetate. This
pheromone and other recently described or potential chemical signals are
compared to compounds in insect pheromone blends. Such knowledge of the
chemical ecology of the Asian elephant has potentially important
implications for conservation.
Raubenheimer,
E.J., Bosman, M.C., Vorster, R., Noffke, C.E., 1998. Histogenesis of the
chequered pattern of ivory of the African elephant (Loxodonta africana).
Arch Oral Biol 43, 868-977.
Abstract: This study aimed to propose a hypothesis on the events which
lead to the development of the characteristic chequered pattern of
elephant ivory. Twenty fragments of ivory and six elephant tusks were
obtained through the National Parks Board of South Africa. Polished
surfaces were prepared in sagittal and longitudinal planes and the
characteristics of the distinctive chequered pattern described. Light-
and electron-microscopical techniques and image analyses were employed
to determine the morphological basis of the pattern and to describe the
spatial distribution, density and morphology of the dentinal tubules.
These investigations showed that the distinctive pattern was the result
of the sinusoidal, centripetal course followed by dentinal tubules. The
apical, slanted part of the sinusoidal curve is the result of the
centripetally moving odontoblast, which, during formation of ivory,
progresses towards the centre of the tusk on a decreasing circumference.
It is suggested that this leads to cell crowding, increased pressure
between odontoblasts and subsequent apical movement of their cell
bodies, cell degeneration and fusion. Odontoblastic degeneration and
fusion probably relieve the pressure between the crowded odontoblasts by
reducing their numbers and the remaining odontoblasts now orientate
their centripetal course towards the tip of the tusk, thereby forming
the anterior-directed part of the sinusoidal path of the tubule. As
odontoblasts progress centripetally the diameter of the pulpal cavity
decreases further and the processes of apical movement, fusion and
degeneration of odontoblasts are repeated. This occurs until the pulpal
cavity is obliterated.
Tada, T.,
Watanabe, Y.H., Matsuoka, A., Ikeda-Saito, M., Imai, K., Ni-hei, Y.,
Shikama, K., 1998. African elephant myoglobin with an unusual
autoxidation behavior: comparison with the H64Q mutant of sperm whale
myoglobin. Biochim Biophys Acta 1387, 165-176.
Abstract: Elephant myoglobins both from Asian and African species have a
glutamine in place of the usual distal (E7) histidine at position 64. We
have isolated native oxymyoglobin directly from the skeletal muscle of
African elephant (Loxodonta africana), and examined the autoxidation
rate of oxymyoglobin (MbO2) to metmyoglobin (metMb) as a function of pH
in 0.1 M buffer at 25 degreesC. As a result, African elephant MbO2 was
found to be equally resistant to autoxidation as sperm whale myoglobin.
However, the elephant myoglobin exhibited a distinct rate saturation
below pH 6. Kinetic analysis of the pH profiles for the autoxidation
rate has disclosed that African elephant MbO2 does not show any
proton-catalyzed process, such as the one that can play a dominant role
in the autoxidation reaction of sperm whale myoglobin by involving the
distal histidine as its catalytic residue. Such a greater stability of
African elephant MbO2 at low pH could be explained almost completely by
the single H64Q mutation of sperm whale myoglobin. In African elephant
aqua-metmyoglobin the Soret band was considerably broadened so as to
produce another peak in the pentacoordinate 395 nm region. This unique
spectral feature was therefore analyzed to show that the myoglobin is in
equilibrium between two species, depending upon the presence or absence
of a water molecule at the sixth coordinate position.
Welsch, U.,
Feuerhake, F., van Aarde, R., Buchheim, W., Patton, S., 1998. Histo- and
cytophysiology of the lactating mammary gland of the African
elephant(Loxodonta africana). Cell Tissue Res 294, 485-501.
Abstract: The lactating mammary gland of the African elephant (Loxodonta
africana) has been studied with a panel of morphological techniques
focusing on (1) the functional changes during the secretory process, (2)
proliferative process [by application of proliferating cell nuclear
antigen (PCNA) immunohistochemistry] and apoptotic phenomena [by use of
the TUNEL technique] in the individual lobules, and (3) components of
milk and milk-fat-globule membrane. In the lactating gland, the lobules
are variably differentiated; within a lobule, however, the alveoli are
usually similarly differentiated. The morphology of their alveoli
suggests a classification of the lobules into types 1-3. Lobules of type
1 are composed of immature tubular alveoli with mitotic figures and
numerous PCNA-positive nuclei; advanced type 1 alveoli contain abundant
glycogen and specific secretory granules. Lobules of type 2 are further
subdivided. In type 2a lobules, the epithelial cells of the alveoli form
tall apical protrusions, which in part are occupied by small lipid
droplets and which are pinched off in an apocrine fashion. The number of
lysosomes varies considerably. Type 2b is the most common type, with
striking basal membrane foldings, abundant rough endoplasmic reticulum
cisterns, large Golgi apparatus, numerous mitochondria, lipid droplets,
and protein vesicles with 30- to 90-nm-wide casein micelles. The lipid
droplets are pinched off with minimal amounts of cytoplasm. Type 2c is
composed of alveoli with a cuboidal epithelium and few signs of
secretory activity. Increasing expression of peanut-agglutinin-binding
sites parallels the maturation and differentiation of the glandular
cells. Type 3 lobules are marked by numerous TUNEL-positive nuclei and
large lipid droplets and are apparently degenerating structures.
Cytokeratin (CK) 14 is usually present in the myoepithelial cells; CK 19
and CK 7 mark ductal and immature alveolar epithelia. Milk protein
content varies between 2.6% and 6.3%, and casein micelles range from 35
to 90 nm in diameter. The diameter of intra-alveolar milk fat globules
ranges from 5 to 25 micrometer and the membranes bear a filamentous
surface coat composed of membrane-anchored mucins; gel-electrophoretic
analysis of these mucins from different individuals demonstrates the
presence of mucin MUC 1, which is expressed with considerable genetic
heterogeneity.
Brown, R.E.,
Butler, J.P., Godleski, J.J., Loring, S.H., 1997. The elephant's
respiratory system: adaptations to gravitational stress. Respiratory
Physiology 110, 67.
Abstract: Elephants have had to adapt to gravitational stresses imposed
on their very large respiratory structures. We describe some unusual
features of the elephant's respiratory system and speculate on their
functional significance. A distensible network of collagen fibers fills
the pleural space, loosely connects lung to chest wall but appears not
to constrain lung-chest wall movements. Myriad spaces within the network
and its rich supply of capillaries suggest effective local sources and
sinks for pleural fluid that may replace the gravity-dependent flows of
smaller mammals. The lung is partitioned into approximately equal to 1
cm3 parenchymal units by a system of thick, elastic septa that ramify
throughout the lung from origins on the lung's elastic external capsule.
Parenchymal units suspended upon the elastic septal system protect
dependent alveoli from compression, thereby reducing the usual
gravitational gradient of lung expansion. Intra-pulmonary airways are
devoid of cartilage, instead they appear to derive resistance to
collapse from tethering forces of the attached septa.
Keet, D.F.,
Grobler, D.G., Raath, J.P., Gouws, J., Carstens, J., Nesbit, J.W., 1997.
Ulcerative pododermatitis in free-ranging African elephant (Loxodonta
africana) in the Kruger National Park. Onderstepoort Journal of
Veterinary Research 64, 25-32.
Abstract: The occurrence of severe lameness in adult African elephant
bulls in a shrub Mopane (Colophospermum mopane) ecosystem was
investigated. Large ulcers in the soles of at least one front foot were
seen in each of the recorded cases. Microscopically, the lesion can be
described as a severe, chronic-active, ulcerative, bacterial
pododermatitis (complicated by hypersensitivity/septic vasculitis). A
variety of bacteria were isolated from these lesions as well as from
regional lymph nodes. Streptococcus agalactiae was the most
consistent isolate, while Dichelobacter nodosus, the only
organism known to be involved with foot disease in domestic ruminants,
was isolated from two cases. Contributory factors such as body mass,
portal of entry and origin of potential pathogens may have predisposed
to the development of the lesions.
Pribe, C.,
Grossberg, S., Cohen, M.A., 1997. Neural control of interlimb
oscillations. II. Biped and quadruped gaits and bifurcations. Biol
Cybern 77, 141-152.
Abstract: Behavioral data concerning animal and human gaits and gait
transitions are simulated as emergent properties of a central pattern
generator (CPG) model. The CPG model is a version of the
Ellias-Grossberg oscillator. Its neurons obey Hodgkin-Huxley type
equations whose excitatory signals operate on a faster time scale than
their inhibitory signals in a recurrent on-center off-surround anatomy.
A descending command or GO signal activates the gaits and triggers gait
transitions as its amplitude increases. A single model CPG can generate
both in-phase and anti-phase oscillations at different GO amplitudes.
Phase transitions from either in-phase to anti-phase oscillations or
from anti-phase to in-phase oscillations can occur in different
parameter ranges, as the GO signal increases. Quadruped vertebrate
gaits, including the amble, the walk, all three pairwise gaits (trot,
pace, and gallop), and the pronk are simulated using this property.
Rapid gait transitions are simulated in the order--walk, trot, pace, and
gallop--that occurs in the cat, along with the observed increase in
oscillation frequency. Precise control of quadruped gait switching uses
GO-dependent modulation of inhibitory interactions, which generates a
different functional anatomy at different arousal levels. The primary
human gaits (the walk and the run) and elephant gaits (the amble and the
walk) are simulated, without modulation, by oscillations with the same
phase relationships but different waveform shapes at different GO signal
levels, much as the duty cycles of the feet are longer in the walk than
in the run. Relevant neural data from spinal cord, globus pallidus, and
motor cortex, among other structures, are discussed.
Sarma, K.K., Dutta, B., 1997.
Preputial
diverticulum in an Asian elephant (Elephas maximus) - a case report.
Indian Veterinary Journal 74, 59-60.
Shoshani, J.,
1997. Origins and evolution. In: Eltringham, M.A. (Ed.), The illustrated
encyclopedia of elephants. Salamander Books Ltd., London, pp. 12-29.
Ullrey, D.E.,
Crissey, S.D., Hintz, H.F. Elephants: Nutrition and Dietary Husbandry:
Nutrition Advisory Group Handbook Fact Sheet 004 September 1997.
Nutrition Advisory Group Handbook , 1-18. 1997.
Ref Type: Electronic Citation
Bezuidenhout,
A.J., Seegers, C.D., 1996. The osteology of the African elephant (Loxodonta
africana): vertebral column, ribs and sternum. Onderstepoort Journal
of Veterinary Research 63, 131-147.
Abstract: The vertebral column, sternum and ribs of the African elephant
were studied and illustrated. In the cervical series, the vertebrae are
characterized by very short (compressed) vertebral bodies and short
spinous processes. There are 20-21 thoracic vertebrae that carry ribs,
and three lumbar vertebrae. The neural arches of the five sacral
vertebrae fuse with each other as well as with the wings of the ilium,
while the intervertebral discs do not ossify and the vertebral bodies
remain separate. There are 19-21 caudal vertebrae. In the latter, the
neural arches of only the first five to six vertebrae fuse dorsally, the
vertebral foramens of the other vertebrae as well as the vertebral canal
remain open dorsally.The body of the first rib is greatly expanded while
that of the last three to four ribs are reduced. The cartilages of the
first six ribs articulate with the sternum, the last five to six ribs do
not bear costal cartilages and are not attached to the costal arch.The
sternum consists of five sternabrae that form three approximately equal,
but separate, segments. The first segment is formed by the first
sternabra, the second segment is formed by the second to fourth
sternabrae and the last segment is formed by the fifth sternabra. The
first and second sternabrae articulate with each other by means of a
synovial joint, the second to fourth sternabrae are fused to each other
and the fourth and fifth sternabrae are loosely attached to each other
by connective tissue.
Foged, N.T.,
Delaisse, J.M., Hou, P., Lou, H., Sato, T., Winding, B., Bonde, M.,
1996. Quantification of the collagenolytic activity of isolated
osteoclasts by enzyme-linked immunosorbent assay. J Bone Miner Res 11
, 226-237.
Abstract: Difficulties in the geometrical definition and measurement of
resorption pits is a major problem for the quantitative analysis of bone
resorption by isolated osteoclasts cultured on bone or dentin
substrates. In this study we developed an enzyme-linked immunosorbent
assay (ELISA) for quantification of bone resorption in vitro, which
specifically quantifies type I collagen fragments released into the
culture medium by the resorptive action of bone cells cultured on slices
of bone or dentin. A consistently high correlation between the formation
of resorption pits and the release of antigenic collagen fragments was
observed for isolated rabbit osteoclasts seeded at various densities and
cultured for various periods on bovine, elephant, and human substrates.
In a further support of the osteoclastic nature of the collagenolytic
effects, a high consistency between pit formation and collagenolysis was
also observed when the rabbit bone cells were cultured in the presence
of very differently acting but typical inhibitors of pit formation,
i.e., the carbonic anhydrase inhibitor acetazolamide, the cysteine
proteinase inhibitor epoxysuccinyl-L-leucylamido-(4-guanodino)butane
(E-64), the phosphatidyl-inositol 3-kinase inhibitor wortmannin, and the
bisphosphonate ibandronate (BM 21.0955). In conclusion, the ELISA
represents a simple, precise, and objective way to dynamically monitor
bone resorption in vitro through quantification of the collagenolytic
activity of isolated osteoclasts.
Kaufman, M.H.,
1996. Observations on Barclay's elephant. J R Coll Surg Edinb 41,
75-81.
Abstract: This account attempts to trace the fate of the skeleton of an
elephant that was gifted by George Ballingall to Dr John Barclay, one of
the most important teachers of Anatomy in Edinburgh during the early
19th century. In his will, elephant, to the Royal College of Surgeons of
Edinburgh on two conditions, that a hall should be built to house the
collection, and that it should be associated with his name in
perpetuity. In the 1830s, the comparative collection, but particularly
the skeleton of the elephant, was the pride of the College.
Unfortunately, interest in the comparative material rapidly diminished,
and, due to constraints on space, while the elephant's skull was
retained the rest of the skeleton was disposed of. An unpublished poem
written at the time of the Burke trial, in 1829, testifies to the fact
that Barclay's elephant was closely associated in the minds of the
public with the activities of Dr Robert Knox, the then Conservator of
the College museum.
Lewandowski,
K., Busch, T., Lewandowski, M., Keske, U., Gerlach, H., Falke, K.J.,
1996. Evidence of nitric oxide in the exhaled gas of Asian elephants
(Elephas maximus). Respiratory Physiology 106, 91-98.
Abstract: Nitric oxide (NO) produced in the respiratory tract is
released into the respiratory gases of humans, rabbits, guinea-pigs, and
rats. We analysed the NO concentrations in the exhaled gas of four awake
Asian elephants. Two methods were employed: (1) exhaled gas was sampled
from the elephants' trunks with a 1 L syringe and analysed for NO
concentrations by chemiluminescence; (2) respiratory gas was
continuously aspirated via a thin plastic tube positioned within the
trunk and on-line analysed for NO concentrations by chemiluminescence.
Syringe sampling (n = 4), when corrected for dilution by ambient air
using linear regression analysis, revealed a mean NO concentration of 31
parts per billion (ppb); highest exhalatory concentrations measured
during continuous suctioning were 27 and 28 ppb (n = 2). The exhaled NO
concentrations in elephants are similar to those found in humans
measured with a comparable technique. This supports the hypothesis that
a size-independent 'normal value' of endogenous NO is provided in the
airways which may contribute to regulation of pulmonary ventilation and
perfusion by autoinhalation in some mammals.
Soltysiak,
Z., 1996. Age-related changes in the brain of an Indian elephant.
Zycie-Weterynaryjne 71, 309-311.
Van Aswegen,
G., Van Noorden, S., Kotze, S.H., de Vos, V., Schoeman, J.H., 1996. The
intestine and endocrine pancreas of the African elephant: a
histological, immunocytochemical and immunofluorescence study.
Onderstepoort Journal of Veterinary Research 63, 335-340.
Abstract: Histological, immunocytochemical and immunofluorescence
methods were employed to study the intestine and endocrine pancreas of
the elephant. The histological findings were in line with those in
monogastric animals. In the mucosa of intestine, endocrine cells were
immunoreactive to somatostatin, gastrin, CCK, GIP, secretin, motilin,
glucagon and NPY. Nerve cells immunoreactive to somatostatin, substance
P, VIP, PHI, NPY, bombesin and CGRP were detected. No immunoreactivity
to neurotensin was observed. Islets of the pancreas had insulin cells in
their cores and glucagon and somatostatin cells in their mantles. The
antisera employed failed to demonstrate PP cells in the pancreas, but
NPY-immunoreactive cells were present.
Bisig, D.A., Di Iorio, E.E., Diederichs, K., 1995.
Crystal
structure of Asian elephant (Elephas maximus) cyanometmyoglobin
at 178-A resolution. Phe29(B10) accounts for its unusual ligand binding
properties. Journal of Biological Chemistry 270, 20752-20754.
Abstract: The crystal structure of Asian elephant cyano-metmyoglobin
which has a glutamine instead of the usual distal site histidine has
been determined to high resolution. In addition to this replacement, the
substitution of a conserved leucine residue in position 29(B10) at the
distal side by a phenylalanine was unambiguously identified based on the
available electron density. The suspicion, that there were errors in the
original sequence which has caused some confusion, is thus confirmed.
Comparison with other myoglobin structures in various ligated forms
reveals an essentially unchanged tertiary structure in elephant
myoglobin despite the two amino acid substitutions in the heme pocket.
Our current structural model shows that the N epsilon 2 atom of
Gln64(E7) has moved with respect to the corresponding nitrogen position
of His64(E7) in the CO complex of sperm whale myoglobin. The newly
assigned residue Phe29(B10) penetrates into the distal side of the heme
pocket approaching the ligand within van der Waals distance and causing
a much more crowded heme pocket compared to other myoglobins. Kinetic
properties of Asian elephant myoglobin, wild type, and recombinant sperm
whale myoglobins are discussed in relation to the structural
consequences of the two amino acid substitutions H64Q and L29F.
Coetzee,
H.L., Kotze, S.H., Lourens, N., 1995. Characterization of mucus
glycoproteins in the intestinal mucosa of the African elephant
(Loxodonta africana) following lectin histochemistry. Onderstepoort
Journal of Veterinary Research 62, 187-192.
Abstract: The glycoproteins of the small intestines, caecum and colon of
three adult elephants and one recently weaned elephant calf were
examined by means of lectin histochemistry. Tissue sections were
histochemically stained with peroxidase-labelled concanavalin A (Con A),
asparagus-pea (TPA), peanut (PNA) and wheat-germ (WGA) lectins. Con A
and TPA showed no binding activity in the intestinal tract of the adult
elephants or the duodenum and ileum of the elephant calf, but did show a
small amount of binding activity in the caecum and colon of the calf.
WGA bound very intensely throughout the intestinal tracts of the adults
and of the calf--especially with the goblet cells located in the crypts
of Lieberkuhn and the glands of Brunner--decreasing in intensity towards
the luminal surface of the intestinal tract. PNA stained the glands of
Brunner of the duodenum faintly and the goblet cells of the ileum
moderately, with no staining of the caecum and faint staining of the
colon. These results show the distribution of Con A-, WGA-, PNA- and TPA-binding
sites, and the changes that take place in the type of glycoprotein
secreted after a change in the diet of the animal.
Endo, H.,
Yamada, T.K., Suzuki, N., Suwa, G., Uetsuka, K., Hashimoto, O.,
Kurohmaru, M., Hayashi, Y., 1995. Ultrastructure of cardiac myocyte in
the Asian elephant (Elephas maximus). Journal of Veterinary Medical
Science 57, 1035-1039.
Abstract: Cardiac myocytes of an Asian elephant (Elephas maximus) were
observed by transmission electron microscopy. Typical ultrastructural
features of cardiac myocytes are exhibited in the musculature of both
the left and right atria, and left ventricle of the heart. Myofibrils,
mitochondria, T-system and sarcoplasmic reticulum are well-developed
within the cytoplasm. Many mitochondria are characteristically
concentrated is some myocytes. Cardiac musculature is also distributed
in the root of the caudal vena cava. Many atrial granules are detected
not only in atrial myocytes, but also in the myocytes of the caudal vena
cava. Atrial natriuretic polypeptide may be secreted from the caval
venous wall in the elephant.
Kramer, B.,
Hattingh, J., 1995. The neuromuscular junction in the African elephant
Loxodonta africana and African buffalo Syncerus caffer.
South African Journal of Wildlife Research 25, p14, 3p, 2bw.
Abstract: Differences in the physiological response to the drug
succinyldicholine occur between the African elephant Loxodonta
africana and African buffalo Syncerus caffer, irrespective of
the route of administration of the drug. The response in elephants has
suggested the presence of unique acetylcholine receptors in their
respiratory muscles. In this paper the first observations of the
neuromuscular junction in the African elephant and African buffalo are
reported. While the basic structure of the junction was found to be
typically mammalian in both species, differences were found in the
morphology of the postjunctional area where these receptors reside.
Elucidation of the structure and function of this junction in these
animals is important in the selection of drugs that act as neuromuscular
blockers.
Langman,
V.A., Roberts, T.J., Black, J., Maloiy, G.M.O., Heglund, N.C., Weber,
J.M., Kram, R., Taylor, C.R., 1995. Moving cheaply: energetics of
walking in the African elephant. J Exp Biol 198 (Pt 3 ),
629-632.
Abstract: Large animals have a much better fuel economy than small ones,
both when they rest and when they run. At rest, each gram of tissue of
the largest land animal, the African elephant, consumes metabolic energy
at 1/20 the rate of a mouse; using existing allometric relationships, we
calculate that it should be able to carry 1 g of its tissue (or a load)
for 1 km at 1/40 the cost for a mouse. These relationships between
energetics and size are so consistent that they have been characterized
as biological laws. The elephant has massive legs and lumbers along
awkwardly, suggesting that it might expend more energy to move about
than other animals. We find, however, that its energetic cost of
locomotion is predicted remarkably well by the allometric relationships
and is the lowest recorded for any living land animal.
Maluf, N.S.R.,
1995. Kidney of elephants. Anatomical Record 242, 491-514.
Abstract: BACKGROUND: Elephants are an important and isolated order.
Their kidneys need substantial investigation and hitherto have not been
portrayed even by a pyelogram. METHODS: Pyelograms and injection of
vessels with colored acrylic emulsions were done initially. Dissection
was under fiberoptics using a dissecting microscope with frequent
measurements. Special areas were cut for microscopy (light and electron)
and photography. Glomerular counts were done by macerating weighted
pieces of cortex and later finding the cortical fraction of the renal
parenchyma. RESULTS: The elephant kidney is devoid of dorsoventral
symmetry. It is composed of 8 +/- 2 lobes separated by fine interlobar
septa. There is no reduction of lobes with maturity. The pelvis
bifurcates at the sinus into primary branches or infundibula which
dispatch a secondary branch or infundibulum into every lobe. Interlobar
arteries and veins, nerves, fat, and connective tissue generally
accompany every secondary infundibulum into its lobe. A major branch of
the renal artery may perforate the renal capsule and course to the
cortico-medullary (C-M) border independently of the secondary
infundibulum to that lobe. The number of glomeruli per kidney is
approximately 15 x 10(6). In adults the glomerular mass is 4.9 +/- 0.5%
of the renal parenchyma and 6.7 +/- 0.3% of the cortex. Areae cribrosae
occur generally at low papillae. They are the outlets of numerous
terminal collecting ducts which may be accompanied by a tubus maximus (T.M.)
A T.M. of diameter 1.6 mm and length 10 mm may act as the only
substitute for an area cribrosa. Wide anastomoses between the two main
renal veins occur within the renal sinus. Intralobar arteries and veins
often course right through the outer medulla to and from, respectively,
the C-M border. CONCLUSIONS: Anatomically, an elephant's kidneys appear
to be able to concentrate urine only moderately. Their kidneys tend to
resemble those of the manatee but not of the dugong.
Nummela, S.,
1995. Scaling of the mammalian middle ear. Hear Res 85, 18-30.
Abstract: This study considers the general question how animal size
limits the size and information receiving capacity of sense organs. To
clarify this in the case of the mammalian middle ear, I studied 63
mammalian species, ranging from a small bat to the Indian elephant. I
determined the skull mass and the masses of the ossicles malleus, incus
and stapes (M, I and S), and measured the tympanic membrane area, A1.
The ossicular mass (in mg) is generally negatively allometric to skull
mass (in g), the regression equation for the whole material (excluding
true seals) being y = 1.373 x(0.513). However, for very small mammals
the allometry approaches isometry. Within a group of large mammals no
distinct allometry can be discerned. The true seals (Phocidae) are
exceptional by having massive ossicles. The size relations within the
middle ear are generally rather constant. However, the I/M relation is
slightly positively allometric, y = 0.554 x(1.162). Two particularly
isometric relations were found; the S/(M + I) relation for the ossicles
characterized by the regression equation y = 0.054 x(0.993), and the
relation between a two-dimensional measure of the ossicles and the
tympanic membrane ares, (M + I)2/3 /A1. As in isometric ears the sound
energy collected by the tympanic membrane is linearly related to its
area, the latter isometry suggests that, regardless of animal size, a
given ossicular cross-sectional area is exposed to a similar
sound-induced stress. Possible morphological middle ear adaptations to
particular acoustic environments are discussed.
Raubenheimer,
E.J., van Heerden, W.F., van Niekerk, P.J., de Vos, V., Turner, M.J.,
1995. Morphology of the deciduous tusk (tush) of the African elephant
(Loxodonta africana). Arch Oral Biol 40, 571-576.
Abstract: The tusk of the African elephant is preceded by a deciduous
tooth generally known as the tush. Tushes from nine elephant fetuses and
six calves younger than 1 year were exposed by dissection and described
morphologically. All tushes consisted of a crown, root and pulpal
cavity, the formation of which is completed soon after birth. They
reached a maximum length of 5 cm, appeared not to erupt through the skin
and were pushed aside and resorbed during enlargement of the distally
located primordium of the tusk. Dental enamel, which covered the crown,
could easily be removed and consisted of rods with an interwoven
arrangement; the dentine-enamel junction was flat. Cellular cementum
extended for variable distances over the crown and the dentine was
tubular in nature. Although the tush apparently has no function, it
provides the anlage and orientation for the development of its permanent
successor.
Van-der-Merwe,
N.J., Bezuidenhout, A.J., Seegers, C.D., 1995. The skull and mandible of
the African elephant (Loxodonta africana). Onderstepoort Journal of
Veterinary Research 62, 245-260.
Abstract: In the present study the bones of the skull, excluding the
hyoid apparatus, are described. All the bones are aerated by sinuses. In
the occipital bone the squamous part is aerated from the sinus of the
parietal bone, the lateral part is aerated from the tympanic bulla and
the basal part from the sinus of the basisphenoid bone. Condylar
foramens and hypoglossal canals are absent. A small interparietal bone
is present at birth. At an early age it fuses with the surrounding
cranial bones. The squamous part of the temporal bone lies sagittally in
young animals, but moves progressively to a transverse plane as the
animals age. A foramen lacerum is represented by jugular and oval
foramens and the carotid canal. The body of the basisphenoid bone is
excavated by the massive maxillary tuberosity. The latter extends to the
oval foramen and contains the developing molar teeth. The ethmoturbinate,
nasal and lacrimal bones are exceptionally small. In old bulls the
palatine process of the incisive bones and their sinuses are gradually
displaced by the palatine process of the maxillae.
Kotze, S.H.,
Coetzee, H.L., 1994. A histocytochemical study of mucus glycoproteins or
mucins in the intestinal tract of the African elephant (Loxodonta
africana). Onderstepoort Journal of Veterinary Research 61,
177-181.
Abstract: The distribution of neutral mucins, sialomucins and
sulphomucins was determined histochemically in the duodenum, jejunum,
ileum and colon of the African elephant (Loxodonta africana). The
techniques used were periodic acid-Schiff (PAS), alcian blue/periodic
acid-Schiff (AB-PAS), high-iron-diamine/alcian blue (HID-AB), alcian
blue at varying pH solutions and alcian blue at high temperature after
methylation and saponification. Acid mucins appear to dominate neutral
mucins, the latter decreasing toward the large intestine. Sulphomucins
and sialomucins occurred in almost equal amounts throughout the
intestinal tract, with a slight decrease of sialomucins toward the
colon.
Ringo, J.L.,
Doty, R.W., Demeter, S., Simard, P.Y., 1994. Time is of the essence: a
conjecture that hemispheric specialization arises from interhemispheric
conduction delay. Cereb Cortex 4, 331-343.
Abstract: Tomasch (1954) and Aboitiz et al. (1992) found the majority of
the fibers of the human corpus callosum are under 1 micron in diameter.
Electron microscopic studies of Swadlow et al. (1980) and the detailed
study of LaMantia and Rakic (1990a) on macaques show the average size of
the myelinated callosal axons also to be less than 1 micron. In man, the
average-sized myelinated fiber interconnecting the temporal lobes would
have a one-way, interhemispheric delay of over 25 msec. Thus, finely
detailed, time-critical neuronal computations (i.e., tasks that strain
the capacity of the callosum and hence could not be handled by just the
larger fibers) would be performed more quickly via shorter and faster
intrahemispheric circuits. While one transit across the commissural
system might yield tolerable delays, multiple passes as in a system
involving "setting" would seem prohibitively slow. We suggest that these
temporal limits will be avoided if the neural apparatus necessary to
perform each high-resolution, time-critical task is gathered in one
hemisphere. If the, presumably overlapping, neural assemblies needed to
handle overlapping tasks are clustered together, this would lead to
hemispheric specialization. The prediction follows that the large brains
of mammals such as elephants and cetaceans will also manifest a high
degree of hemispheric specialization.
Shoshani, J.,
1994. Skeletal and other basic anatomical features of elephants. In:
Shoshani, J., Tassy, P. (Eds.), The proboscidea: evolution and
paleoecology of elephants and their relatives. Oxford University Press,
Oxford, pp. 9-20.
Smuts, M.M.S.,
Bezuidenhout, A.J., 1994. Osteology of the pelvic limb of the African
elephant (Loxodonta africana). Onderstepoort Journal of
Veterinary Research 61, 51-66.
Abstract: The pelvic girdle was characterized by large,
transversely-placed ilial wings. The femur was the longest bone of the
skeleton and its fovea capitis was situated caudomedially between the
epiphyseal line and the articular surface of the femoral head. A
wedge-shaped patella articulated with the femoral trochlea. The bones of
the crus were approximately half as long as the femur and consisted of
the sturdy tibia and slender fibula. The condyles of the tibia were
concave and the femoro-tibial joint was congruent with rudimentary
menisci. The tarsus consisted of seven bones which were arranged in
three rows. There were five metatarsal bones. Only four digits were
present, the third and fourth consisted of three phalanges each while
the second and fourth digits were smaller and consisted of two phalanges
each. The first digit was represented by one proximal sesamoid bone
only. A large, cartilagenous rod or pre-hallux was attached to the first
tarsal and metatarsal bones. Proximal sesamoid bones were present on the
plantar aspect of the trochleae of metatarsal bones 1-V. The pes was
found to be digitigrade and the digits rested on a thick pad of elastic
connective tissue and fat.
Van-Aswegen, G., Schoeman, J.H., De-Vos, V., Van-Noorden, S., 1994.
The
oesophagus and stomach of the African elephant: a histological,
immunocytochemical and immunofluorescence study. Onderstepoort Journal
of Veterinary Research 61, 223-229.
Abstract: Histological, immunocytochemical and immunofluorescence
methods were employed to study the oesophagus and stomach of the
elephant. The histological findings were similar to those in monogastric
species like pigs and humans. In the mucosa of the stomach, endocrine
cells were immunoreactive to gastrin, somatostatin, chromogranin A and
serotonin. Nerve cells immunoreactive to somatostatin, bombesin, VIP,
PHI and CGRP were detected in the submucosal and myenteric plexus of the
stomach. In the stomach, the absence of glucagon cells and the presence
of endocrine cells immunoreactive to PYY, are in contrast to the
situation in other mammals and need further investigation. Small gastric
ulcers were observed in some of the specimens.
Bechert,
U.S., 1993. Morphology and physiology. Animal Keepers' Forum 20,
111-115.
Cupane, A.,
Leone, M., Vitrano, E., Cordone, L., Hiltpold, U.R., Winterhalter, K.H.,
Yu, W., DiIorio, E.E., 1993. Structure-dynamics-function relationships
in Asian elephant (Elephas maximus)myoglobin. An optical spectroscopy
and flash photolysis study on functionally important motions. Biophys J
65, 2461-2472.
Abstract: In this work we report the thermal behavior (10-300 K) of the
Soret band lineshape of deoxy and carbonmonoxy derivatives of Asian
elephant (Elephas maximus) and horse myoglobins together with their
carbon monoxide recombination kinetics after flash photolysis; the
results are compared to analogous data relative to sperm whale myoglobin.
The Soret band profile is modeled as a Voigt function that accounts for
the coupling with high and low frequency vibrational modes, while
inhomogeneous broadening is taken into account with suitable
distributions of purely electronic transition frequencies. This analysis
makes it possible to isolate the various contributions to the overall
lineshape that; in turn, give information on structural and dynamic
properties of the systems studied. The optical spectroscopy data point
out sizable differences between elephant myoglobin on one hand and horse
and sperm whale myoglobins on the other. These differences, more
pronounced in deoxy derivatives, involve both the structure and dynamics
of the heme pocket; in particular, elephant myoglobin appears to be
characterized by larger anharmonic contributions to soft modes than the
other two proteins. Flash photolysis data are analyzed as sums of
kinetic processes with temperature-dependent fractional amplitudes,
characterized by discrete pre-exponentials and either discrete or
distributed activation enthalpies. In the whole temperature range
investigated the behavior of elephant myoglobin appears to be more
complex than that of horse and sperm whale myoglobins, which is in
agreement with the increased anharmonic contributions to soft modes
found in the former protein. Thus, to satisfactorily fit the time
courses for CO recombination to elephant myoglobin five distinct
processes are needed, only one of which is populated over the whole
temperature range investigated. The remarkable convergence and
complementarity between optical spectroscopy and flash photolysis data
confirms the utility of combining these two experimental techniques in
order to gain new and deeper insights into the functional relevance of
protein fluctuations.
Kern, T.J.,
Murphy, C.J., Howland, H.C. Physiological optics and ocular anatomy of
the Asian elephant (Elephas maximus). Proceedings of the American
Association of Zoo Veterinarians. 355. 1993.
Ref Type: Conference Proceeding
Rasmussen,
L.E.L., Johnson, E.W., Jafek, B.W. Preliminary observations on the
morphology of the vomeronasal organ of a newborn Asian elephant.
Chemical Senses 18, 618. 1993.
Ref Type: Abstract
Abstract: Abstract. Full-text. Adult Asian elephants have an
apparently typical mammalian vomeronasal organ (VNO). Presumably,
flehmen responses aid in the presentation of bioactive molecules to
vomeronasal neuroreceptors. Young Asian elephants do not exhibit
flehmen responses until 6-17 weeks after birth. Histological studies of
VNO in newborn elephants have not been available. Recently, at the
light microscopic level, we have observed a structure that in gross
appearance is similar to the VNO of other mammals; there is a lumen
surrounded by a convex and a concave epithelial border, those borders
join at both ends. Based on previous studies, we presume that the
concave border would be the neuroepithelium with the receptor cells. The
epithelia of both surfaces are pseudostratified. Within these epithelia
are cells with different nuclear morphologies. Some of the nuclei are
euchromatic and oval. Other appear heterochromatic. Round basal cells
are also apparent. At the surfaces of the epithelia some ciliated cells
can be seen. To our knowledge, ciliated cells have been identified in
the VNO neuroepithelium of only one other mammalian species. To further
document the cell types found in the newborn elephant VNO and to attempt
to identify receptor cells, we will do electron microscopy on
representative regions.
Smuts, M.M.S.,
Bezuidenhout, A.J., 1993. Osteology of the thoracic limb of the African
elephant (Loxodonta africana). Onderstepoort Journal of Veterinary
Research 60, 1-14.
Abstract: The forelimb bones of 8 elephants (7 adults, 1 juvenile) were
studied. In addition, the bones of the digits were dissected and studied
in situ in a mature specimen. The scapula, humerus and bones of the
antebrachium (particularly the ulna) are massive in comparison to the
short, relatively small bones of the manus. There are 8 carpal bones, 5
metacarpal bones and 5 digits. Digits 2-4 consist of 3 phalanges each.
The 5th digit consists of 2 phalanges, while the 1st is represented by a
single phalanx which is tusk-like and pointed. The distal phalanges of
digits 2-4 are very small and do not articulate with the middle
phalanges. The proximal sesamoids are well developed and are present on
the palmar aspect of all 5 metacarpophalangeal joints. All the bones are
illustrated from at least 2 aspects.
Vyas, K.,
Rajarathnam, K., Yu, L.P., Emerson, S.D., La Mar, G.N., Krishnamoorthi,
R., Mizukami, H., 1993. 1H NMR investigation of the heme cavity of
elephant (E7 Gln)met-cyano-myoglobin. Evidence for a B-helix
phenylalanine interaction with bound
ligand. J Biol Chem 268, 14826-14835.
Abstract: A combination of one- and two-dimensional NMR experiments has
been used to identify and spatially locate the heme pocket residues in
the paramagnetic, low spin, met-cyano complex of elephant myoglobin. In
addition to assigning resonances of the conserved residues, we have also
assigned Gln64 (E7) and an aromatic ring designated PheA whose side
chain is inserted into the heme pocket, as found earlier for elephant
carbonmonoxy-myoglobin and oxy-myoglobin (Yu, L. P., La Mar, G. N., and
Mizukami, H. (1990) Biochemistry 29, 2578-2585). The assigned conserved
proximal side residues (Leu89(F4), Ala90(F5), His93(F8), His97(FG3),
Ile99(FG5), Leu104(G5), Phe138(H15), and Tyr146(H23)) and conserved
distal side residues (Phe43(CD1), Thr67(E10), Val68(E11), and
Ala71(E14)) in elephant met-cyano-myoglobin are found to have
orientations similar to those in sperm whale met-cyano-myoglobin. The
observed dipolar connectivities and dipolar shift pattern for the
substituted Gln64(E7) place the Gln in the heme pocket oriented toward
the iron, as found for His64(E7). The conserved structural elements
demand that the inserted PheA originate from the B-helix (i.e. Phe27 or
Phe33). Dipolar contacts between the inserted PheA and the conserved
residues Phe43(CD1), Val68(E11), Ile107(G8), and Gln64(E7), place PheA
in the position occupied by the B10 residue in sperm whale myoglobin
(Mb), with the larger size of the PheA side chain as compared to the
replaced Leu being accommodated by the vacancy that occurs in sperm
whale Mb. The paramagnetic induced relaxation places PheA in van der
Waals contact with the bound ligand. Hence we conclude that the B10
position of elephant Mb is occupied by a Phe, and this substitution
relative to sperm whale Mb is responsible for the low autoxidation rate
and low reduction potential of elephant Mb. A reduced autoxidation rate
has been reported for a sperm whale synthetic point mutant Leu29(B10)
--> Phe (Carver, T. E., Brantley, R. E., Jr., Singleton, E. W., Arduini,
R. M., Quillin, M. L., Phillips, G. N., and Olson, J. S. (1992) J. Biol.
Chem. 267, 14443-14450). The published sequence of elephant Mb places
B-helix Phe residues at position 27(B8) and 33(B14), but a Phe at
neither of these positions can account for the observed NMR properties.
Since a large proportion of the substitutions in elephant relative to
sperm whale Mb, and some of the least conservative, occur in the
B-helix, neither a structurally perturbed B-helix nor an error in the
sequence can be discounted.
Chungath, J.J.,
Paily, L., Ommer, P.A., 1992. Anatomy of the vertebral column of the
Indian elephant (Elephas maximus). In: Silas, E.G., Nair, M.K., Nirmalan,
G. (Eds.), The Asian Elephant: Ecology, Biology, Diseases, Conservation
and Management (Proceedings of the National Symposium on the Asian
Elephant held at the Kerala Agricultural University, Trichur, India,
January 1989). Kerala Agricultural University, Trichur, India, pp.
43-45.
Harshan, K.R.,
Chungath, J.J., Paily, L., Ommer, P.A., 1992. Histology of the temporal
gland of the Indian elephant (Elephas maximus). In: Silas, E.G., Nair,
M.K., Nirmalan, G. (Eds.), The Asian Elephant: Ecology, Biology,
Diseases, Conservation and Management (Proceedings of the National
Symposium on the Asian Elephant held at the Kerala Agricultural
University, Trichur, India, January 1989). Kerala Agricultural
University, Trichur, India, pp. 46-48.
Hattingh, J.,
Petty, D., 1992. Comparative physiological responses to stressors in
animals. Comparative Biochemistry and Physiology
A-Comparative-Physiology 101, 113-116.
Abstract: The species-specific experimental response to stressors (SSERTS)
analysis was applied to a number of species under varied short and long
term conditions. The measure provides quantitative data relating to the
physiological responses of animals when exposed to stressors and results
are presented comparing these for different methods of immobilization,
euthanasia, etc. at intra- and inter-species level. It is suggested that
the SSERTS measure is of greater value for measuring the responses of
animals to stressors than is the measurement of the concentration of
single blood variables.
Murphy, C.J.,
Kern, T.J., Howland, H.C., 1992. Refractive state, corneal curvature,
accommodative range and ocular anatomy of the Asian elephant (Elephas
maximus). Vision Res 32, 2013-2021.
Abstract: The resting refractive state of six mature, female, Asian
elephants (Elephas maximus) was determined using streak retinoscopy and
neutralizing video retinoscopy. The amplitude of accommodation was also
measured by neutralizing video retinoscopy of two animals and the
corneal curvatures of three animals was measured by photokeratoscopy.
The net spherical refraction was found to be +0.23 D. No difference was
observed between cyclopleged and non-cyclopleged eyes (data from three
animals), nor was there any difference between right and left eyes. Nine
of the twelve eyes refracted had > or = 0.5 D astigmatism. The mean
corneal power, as measured by photokeratometry was 21.3 D (SD = 1.8 D).
There was a tendency towards with-the-rule corneal astigmatism in our
sample (mean value: 1.2 D), though it did not reach statistical
significance (P = 0.06). Two elephants were examined using neutralizing
video photoretinoscopy. They were able to accommodate through 3 D. Three
fixed eyes from three different elephants were obtained for gross and
microscopic examination. The mean axial length of the eye was 38.75 mm
and the lens had an axial diameter of approx. 10 mm. The posterior
sclera was thick (8.0-8.5 mm). Histologically, the cornea was comprised
of five distinct layers. A thin, meridionally oriented smooth ciliary
muscle was identified. Individual muscle fibers were also observed
associated with the posterior trabeculae of the uveal meshwork.
Ommer, P.A.,
Harshan, K.R., Chungath, J.J., Paily, L., 1992. Histology of the adrenal
gland of the Indian elephant (Elephas maximus). In: Silas, E.G., Nair,
M.K., Nirmalan, G. (Eds.), The Asian Elephant: Ecology, Biology,
Diseases, Conservation and Management (Proceedings of the National
Symposium on the Asian Elephant held at the Kerala Agricultural
University, Trichur, India, January 1989). Kerala Agricultural
University, Trichur, India, pp. 49-50.
Phillips, P.K.,
Heath, J.E., 1992. Heat exchange by the pinnae of the African elephant
(Loxodonta africana). Comparative Biochemistry and Physiology [A] 101,
693-699.
Abstract: 1. Surface temperatures of the pinnae of four female African
elephants were measured at ambient temperatures between 14 and 32
degrees C using infrared thermography. Instantaneous heat losses
calculated using those values ranged from 10.67 to 76.2 W under the
observed conditions. 2. Using a value of 17 kcal/kg/day, those heat
losses account for 0.65-4.64% of the animals' standard metabolic rates,
considering one side of one ear only. 3. A model of heat flow across a
flat vertical plate was constructed and compared to the actual values.
Up to 100% of an African elephant's heat loss needs can be met by
movement of its pinnae and by vasodilation. 4. Thermography indicates
that the temperature distribution pattern across the pinna changes with
ambient temperature and that areas of specialized motor control exist
Shoshani, J.,
1992. Anatomy and physiology. In: Shoshani, J. (Ed.), Elephants.
Majestic creatures of the wild. Rodale Press, Emmaus, Pennsylvania, pp.
66-81.
Teunissen, M.J., de Kort, G.V., Op den Camp, H.J., Huis in 't Veld,
J.H., 1992.
Production of
cellulolytic and xylanolytic enzymes during growth of the anaerobic
fungus Piromyces sp. on different substrates. J Gen Microbiol 138 (Pt 8),
1657-1664.
Abstract: Piromyces sp. strain E2, an anaerobic fungus isolated from an
Indian elephant (hindgut fermenter) was tested for its ability to
ferment a range of substrates. The fungus was able to use bagasse,
cellobiose, cellulose, fructose, glucose, lactose, mannose, starch,
wheat bran, wheat straw, xylan and xylose. Formate and acetate were the
main fermentation products after growth on these substrates. The amount
of carbon found in the fermentation products of cultures, in which
substrate digestion was complete averaged 88.5 mM, or 59% of the carbon
offered as substrate. No growth was observed on other substrates tested.
Lactose, starch, cellobiose and filter paper cellulose were good
inducers of cellulolytic and xylanolytic enzymes. Cellulolytic and
xylanolytic enzymes were produced constitutively by Piromyces strain E2,
although enzyme activities were generally lower after growth on glucose
and other soluble sugars. Complex substrates (bagasse, wheat bran, and
wheat straw) were good inducers for xylanolytic enzymes but not for
cellulolytic enzymes. The extracellular protein banding pattern after
SDS-PAGE was therefore only slightly affected by the growth substrate.
Identical beta-glucosidase and endoglucanase activity patterns were
found after growth on different substrates. This indicated that
differences in enzyme activities were not the result of secretion of
different sets of isoenzymes although it remains possible that the
relative amount of each isoenzyme produced is influenced by the growth
substrate.
Wiesner, H.,
1992. Occurrence of Arcus scleralis in elephants.
Zoologische Garten 62, 287-293.
Cheng, H.C., Yamashiro, D., 1991.
Synthesis and
receptor binding activity of elephant beta- endorphin, a beta-endorphin
homolog with highly potent analgesic activity. International Journal of
Peptide and Protein Research 38, 66-69.
Abstract: Elephant beta-endorphin and its analog, elephant beta-
endorphin(6-31) were synthesized by standard solid phase method.
Receptor binding activity showed that elephant beta-endorphin was five
to six times more potent than human beta-endorphin in its ability to
bind to opiate receptors on rat brain membrane. In a previous study
(Wong, C.-L., Wai, M.-K., Cheng, H.-C., Chung, D. & Yamashiro, D (1990)
Clinical and Experimental Pharmacology and Physiology 16, 33-37), tail
flick test for intracerebroventricularly administered beta-endorphin
showed that the antinociceptive potency of elephant beta-endorphin was
seven to eight times higher than that of human beta-endorphin in mice.
Results from both studies suggest that elephant beta-endorphin was a
much more potent antinociceptive agent than human beta- endorphin in
tail flick test and its higher analgesic activity might be due to its
higher affinity for opiate receptors in the brain.
John, M.C.,
Suramanian, R., 1991. The elephant. Zoos' Print Journal 1-4.
Kozaki, M.,
Oura, R., Sekine, J., 1991. Studies on digestion physiology of
herbivorous feral animals. 2. The comparison of intake of total
digestible nutrients among diverse sizes of ruminant and monogastric
animals. Journal of the Faculty of Agriculture -Tottori-University 27,
61-68.
Abstract: Digestion trials were carried out on elephant, zebra, giraffe,
eland, blackbuck, zebu cattle, Japanese serow, sika deer, muntjac and
Japanese Black steer during 3 different seasons of the year.
Digestibility of organic matter was about 0.6 for all animals except
elephant, muntjac and blackbuck. Crude protein (CP) digestibility
correlated (P<0.01) with CP concentration in the feed ration. Acid
detergent fibre digestibility ranged from 0.3 to 0.4 in ruminants
compared with 0.1 to 0.2 in monogastric animals. No seasonal effects on
digesta were observed.
Kramer, B.,
Teixeira, M., Hattingh, J., 1991. The histology of the adrenal gland of
the African elephant, Loxodonta africana. South African Journal
of Zoology 26, 193-198.
Abstract: The histology, particularly the ultrastructural cytology, of
the adrenal gland of the African elephant, Loxodonta africana, is
virtually unknown. Tissue from 14 adult male and female elephants was
processed for light and transmission electron microscopy. The gland is
surrounded by a thick capsule composed of an outer layer of dense
connective tissue and an inner layer in which smooth muscle fibres
predominate. Below the layer of smooth muscle, a continuous layer of
relatively undifferentiated "capsular" cells occur. Where the capsular
cells abut on the zona glomerulosa, they appear to be differentiating
into glomerulosa cells, as small lipid droplets are present in their
cytoplasm. The cortex is divided into three zones as is found in the
adrenal glands of other mammals. Large amounts of collagenous and
reticular tissue support the secretory cells, which have a marked lipid
content. With electron microscopy, the cortical cells show features
typical of steroid-producing cells. The medulla is characterized by an
outer region of pale-staining chromaffin-positive (adrenaline) cells and
an inner region of intensely staining chromaffin-positive (noradrenaline)
cells. The latter cells contain granules of different sizes and
structure.
Kroll, W. The
straight-tusked elephant of Crumstadt. A contribution to the osteology
of Elephas (Palaeoloxodon) antiquus Falconer & Cautley (1847). Der
Waldelefant von Crumstadt. Ein Beitrag zur Osteologie des Waldelefanten,
Elephas (Palaeoloxodon) antiquus Falconer & Cautley (1847). 1-106.
1991. Munchen, Germany, Tierarztliche Fakultat, Ludwig-Maximilians-Universitat.
Ref Type: Thesis/Dissertation
Ratnasooriya,
W.D., Fernando, S.B.U., Manatunga, A.N.V.R., 1991. Presence of an arcus
senilis-like structure in the eyes of Sri Lankan elephants (Elephas
maximus maximus). Med. Sci. Res. 19, 715-716.
Teunissen,
M.J., Smits, A.A.M., Op den Camp, H.J.M., Huis in't Veld, J.H.J., Vogels,
G.D., 1991. Fermentation of cellulose and production of cellulolytic and
xylanolytic enzymes by anaerobic fungi from ruminant and non- ruminant
herbivores. Arch. Microbiol. 156, 290-296.
Abstract: Four anaerobic fungi were grown on filter paper cellulose and
monitored over a 7-8 days period for substrate utilization, fermentation
products, and secretion of cellulolytic and xylanolytic enzymes. Two of
the fungi (N1 and N2) were Neocallimastix species isolated from a
ruminant (sheep) and the other two fungi were Piromyces species (E2 and
R1) isolated from an Indian Elephant and an Indian Rhinoceros,
respectively. The tested anaerobic fungi degraded the filter paper
cellulose almost completely and estimated cellulose digestion rates were
0.25, 0.13, 0.21 and 0.18 g.l-1.h-1 for strains E2, N1, N2, R1,
respectively. All strains secreted cellulolytic and xylanolytic enzymes,
including endoglucanase, exoglucanase, beta-glucosidase and xylanase.
Strain E2 secreted the highest levels of enzymes in a relatively short
time. The product formation on avicel by enzymes secreted by the four
fungi was studied. Both in the presence and absence of
glucurono-1,5-delta-lactone, a specific inhibitor of beta-glucosidase,
mainly glucose was formed but no cellobiose. Therefore the exoglucanase
secreted by the four fungi is probably a glucohydrolase
Welsch, B.B.,
1991. Elephant dentition. Proceedings American Association of Zoo
Veterinarians 9.
Wilson, J.F.,
Mahajan, U., Wainwright, S.A., Croner, L.J., 1991. A continuum model of
elephant trunks. J Biomech Eng 113, 79-84.
Abstract: A continuum model is presented that relates the trunk
parameters of loading, geometry, and muscle structure to the necessary
conditions of static equilibrium. Linear theory for stress-strain
behavior is used to describe an elephant trunk for an incremental
displacement as the animal slowly lifts a weight at the trunk tip. With
this analysis and experimental values for the trunk parameters, the
apparent trunk stiffness Ea is estimated for the living animal. For an
Asian elephant with a maximum compression strain of 33 percent, Ea is of
the order of 10(6) N/m2. The continuum model is quite general and may be
applied to similar nonskeletal appendages and bodies of other animals.
Cole, G.,
Neal, J.W., 1990. The brain in aged elephants. Journal of Neuropathology
and Experimental Neurology 49, 190-192.
Fischer,
M.S., 1990. The unique ear of elephants and manatees (Mammalia): A
phylogenetic paradox. C. R. Acad. Sci. Ser. III Sci. Vie 311,
157-162.
Hattingh, J.,
Pitts, N.I., Ganhao, M.F., Moyes, D.G., de Vos, V., 1990. Blood
constituent responses of animals culled with succinyldicholine and
hexamethonium. Journal of the South African Veterinary Medical
Association 61, 117-118.
Abstract: Blood constituent responses of elephants and buffaloes culled
in the Kruger National Park, using a mixture of succinyldicholine and
hexamethonium, were compared to those of animals culled with
succinyldicholine only. The results show a decreased physiological
response in the animals culled with the mixture, characterized by lower
total catecholamine, cortisol and glucose concentrations. Neither a
delay of up to 30 min in obtaining blood samples from culled animals,
nor a delay of up to 30 min in processing samples obtained immediately
after cessation of respiration, gave any significant difference in the
blood constituents which were measured.
Rasmussen,
L.E.L., Hultgren, B., 1990. Gross and microscopic anatomy of the
vomeronasal organ in the Asian elephant. In: McDonald, D.W., Muller-Schwarze,
D., Natynczuk, S.E. (Eds.), Chemical signals in vertebrates 5. Oxford
University Press, New York, pp. 154-161.
Rasmussen,
L.E.L., Munger, B. Micro-anatomy of the trunk tip of Elephas maximus.
Chemical Senses 15, 629. 1990.
Ref Type: Abstract
Abstract: Full-text: This study documents the characteristics of the
sensory innervation and cutaneous receptors in the dermal and epidermal
skin of the extreme trunk tip (finger) and adjacent skin of the Asian
elephant Elephas maximus by light microscopy. During the flehmen
response the elephant moistens the trunk tip with liquids of interest
and apparently uses this tip for transport of such substances to the
mucous-filled openings of the incisive ducts, which lead to the
vomeronasal organ. We expected to find this region of the trunk tip
richly innervated, perhaps with specialized nerve endings, especially in
the epidermis. Unexpectedly, our light microscopic examinations
demonstrated three distinctive features. First, a uniquely high density
of free nerve endings are apparent in the superficial layers of the
trunk tip skin. Second, in the skin closely associated with the trunk
tip unusual tiny short vibrissal hairs surrounded by hundreds of axons
were interspersed with more conventional vibrissal hairs. Third, unique
complex branched encapsulated corpuscles were abundant in the
superficial layer of the dermis in the area of the tip and in the
closely associated skin. This study provides basic histological
information about the trunk tip region as the initial part of our
investigation of the innervation, cutaneous sensory receptors,
especially possible chemosensory receptors of the trunk and its
orifices.
Raubenheimer,
E.J., Dauth, J., Dryer, M.J., Smith, P.D., Turner, M.L., 1990. Structure
and composition of ivory of the African elephant (Loxodonta africanus).
South African Journal of Science 86, 192-193.
Roskosz, T.,
Kobrynczuk, F., 1990. Some reflexions on the shape of foramen magnum in
Proboscidea. Annals of Warsaw Agricultural University SGGW AR,
Veterinary-Medicine 15, 3-6.
Sreekumar,
K.P., Nirmalan, G., 1990. Estimation of the total surface area in Indian
elephants (Elephas maximus indicus). Vet. Res. Commun. 14, 5-17.
Abstract: Twenty-four adult Indian elephants (Elephas maximus indicus)
of both sexes and different ages and weights, belonging to the Temple
Devaswoms, the Forest Department of the Government of Kerala and the
Gemini Circus formed the experimental subjects from which formulae were
derived to predict the total surface area from either body measurements
or areas of individual regions. Several models, using the parameters
studied either singly or in combination, were tried independently for
males and females and also for adults irrespective of sex. The best
prediction of total surface area (S) in m2 was obtained for adults
irrespective of sex by using the two parameters, the height at the
shoulders (H) in m and forefoot pad circumference (FFC) in m in the
formula S = -8.245 + 6.807H + 7.073FFC. No significant improvement in
the accuracy of prediction resulted from the use of the independent best
fit formulae for males and females. The conventional method of using the
exponential of body weight (kg) for predicting surface area was not
found to yield an equivalent accuracy in these animals
Stephanos,
J.J., Addison, A.W., 1990. Spectroscopic and kinetic aspects of
Elephas maximus hemoglobin. Eur. J Biochem. 189, 185-191.
Abstract: In comparison with myoglobin and human and Glycera
dibranchiata hemoglobins, the heme distal side amino acid exchanges
within the heme environment of elephant tetrameric hemoglobin (Hbe) only
slightly affect the electronic and ESR spectra of Hbe(III) and Hbe(II)
derivatives, several of which were prepared and characterized by optical
and ESR spectroscopy. Addition of 2,3- bisphosphoglycerate or inositol
hexakisphosphate to Hbe(II)NO causes tension in the Fe-N(proximal His)
bond, although the behaviour differs in detail from that of HbA(II)NO.
There are two equilibrium states of Hbe having significantly different
kinetics for the Hbe(III)----Hbe(II) reaction of Hbe(III)NO. This
autoreduction occurs in the form of two parallel processes, which
collapse into one intermediate rate in the presence of Gri(2, 3)P2. The
temperature dependences of the rates enable deduction of delta H0 and
delta S0 for the linked equilibrium, and yield linear Eyring plots for
Hbe(III)NO, from which activation parameters were estimated on the basis
of a previously described mechanism
Williams, T.M.,
1990. Heat transfer in elephants: thermal partitioning based on skin
temperature profiles. Journal of Zoology (Lond) 222, 235-245.
Abstract: The elephant with its low surface-to-volume ratio presents an
interesting problem concerning heat dissipation. To understand how such
large mammals remain in thermal balance, we determined the major avenues
of heat loss for an adult African elephant and an immature Indian
elephant. Because conventional physiological measurements are difficult
for these animals, the present study used a non-invasive technique,
infrared thermography, to measure skin temperatures of each elephant.
Detailed surface temperature profiles and surface area measurements of
each elephant were used in standard equations for convective, conductive
and radiant heat transfer. Results demonstrated that heat transfer by
free convection and radiation accounted for 86% of the total heat loss
for the elephants at Ta = 12.6 degrees C. Heat transfer
across the ears, an important thermal window at high ambient
temperatures, represented less than 8% of the total heat loss. Surface
area of the animals, and metabolic heat production calculated from total
heat loss of the African elephant, scaled predictably with body mass.
In contrast, the thermal conductance of the elephants (71.6 W/degree
C, African; 84.5 W/degree C, Indian) was three to five times
higher than predicted from an allometric relationship for smaller
mammals. The high thermal conductance of elephants is attributed to the
absence of fur and appears to counteract reduced heat transfer
associated with a low surface-to-volume ratio.
Wong, C.L.,
Wai, M.-K., Cheng, H.-C., Chung, D., Yamashiro, D., 1990. Preliminary
study on the antinociceptive effect of elephant beta-endorphin. Clinical
and Experimental Pharmacology and Physiology 17, 33-37.
Abstract: 1. Intraventricular administration of human beta-endorphin and
elephant beta-endorphin significantly prolonged the tail flick response
tested 30 min later. However, elephant beta-endorphin was about 7-8
times more potent than human beta-endorphin in the tail flick test. 2.
beta-Endorphin antagonized the antinociceptive effect of both human
beta-endorphin and elephant beta-endorphin by the same extent. Naloxone
also antagonized the antinociceptive effects of the beta-endorphins but
it was less effective than beta-endorphin. 3. Human beta-endorphin and
elephant beta-endorphin were of equal potency in inhibiting the
abdominal constriction response induced by intraperitoneal (i.p.) acetic
acid. Both beta-endorphin and naloxone antagonized these effects of the
beta-endorphins with naloxone being more effective. 4. The present study
showed that different opioid receptor subtypes may be involved in the
tail flick test and the abdominal constriction test. Furthermore,
elephant beta-endorphin was a better antinociceptive agent than human
beta-endorphin in the tail flick test.
Yu,
L.P., La Mar, G.N., Mizukami, H., 1990.
Rearrangement
of the distal pocket accompanying E7 His----Gln substitution in elephant
carbonmonoxy- and oxymyoglobin: 1H NMR identification of a
new aromatic residue in the heme pocket. Biochemistry 29,
2578-2585.
Abstract: Two-dimensional 1H NMR methods have been used to assign side-
chain resonances for the residues in the distal heme pocket of elephant
carbonmonoxymyoglobin (MbCO) and oxymyoglobin (MbO2). It is shown that,
while the other residues in the heme pocket are minimally perturbed, the
Phe CD4 residue in elephant MbCO and MbO2 resonates considerably upfield
compared to the corresponding residue in sperm whale MbCO. The new NOE
connectivities to Val E11 and heme-induced ring current calculations
indicate that Phe CD4 has been inserted into the distal heme pocket by
reorienting the aromatic side chain and moving the CD corner closer to
the heme. The C zeta H proton of the Phe CD4 was found to move toward
the iron of the heme by approximately 4 A relative to the position of
sperm whale MbCO, requiring minimally a 3-A movement of the CD helical
backbone. The significantly altered distal conformation in elephant
myoglobin, rather than the single distal E7 substitution, forms a
plausible basis for its altered functional properties of lower
autoxidation rate, higher redox potential, and increased affinity for CO
ligand. These results demonstrate that one-to-one interpretation of
amino acid residue substitution (E7 His----Gln) is oversimplified and
that conformational changes of substituted proteins which are not
readily predicted have to be considered for interpretation of their
functional properties
Bianchi, M.,
1989. The thickness, shape and arrangement of elastic fibres within the
nuchal ligament from various animal species. Anatomischer Anzeiger 169,
53-66.
Abstract: From studies of the nuchal ligament from several species of
ruminant (including cattle, sheep, goats, giraffe, dromedary, buffalo),
equids (horses, mules, donkeys), carnivores (12 dogs of different breeds
and body size) and an elephant, it was concluded that the thickness of
the elastic fibres of the ligament was not directly correlated with the
size. During postnatal growth the following structural changes were
identified: increase in thickness and length of preexisting elastic
fibres; progressive increase in the nuber of fibre splittings and of
collaterals given off by individual fibres; neoformation of elastin
fibres and their addition to existing ones. In bovines, the thickest
elastic fibres had attained their full size by 6 months of age.
de
Villiers, D.J., Skinner, J.D., Hall-Martin, A.J., 1989.
Circulating
progesterone concentrations and ovarian functional anatomy in the
African elephant (Loxodonta africana). Journal of Reproduction
and Fertility 86, 195-201.
Abstract: Mean plasma progesterone concentrations measured in pregnant
and non-pregnant elephants did not differ significantly from each other
because of considerable variation, particularly for stage of pregnancy.
Maximum progesterone values were recorded during early pregnancy (5-8
months) and declined towards term (22 months). The numbers of corpora
lutea or total luteal tissue volume were not critical in maintaining
progesterone secretion. An increase in plasma progesterone
concentrations with the luteal phase of the ovarian cycle was evident.
A possible role of the placenta in the second half of gestation is
indicated by an increase in fetal progesterone concentrations towards
term.
Fujikura, T.,
Oura, R., Sekine, J., 1989. Comparative morphological studies on
digestion physiology of herbivores. 1. Digestibility and particle
distribution of digesta and feces of domestic and feral animals. Journal
of the Faculty of Agriculture -Tottori-University 25, 87-93.
Abstract: Digesta was collected from a Japanese Black steer 30 months
old and feed and faeces samples were collected from a sheep, goat,
camel, wallaby, elephant, horse and koala. The composition of feeds and
intakes for each animal is given in tables. Digestibilities of particle
distribution of DM and acid detergent fibre are discussed and compared
between animals.
Harris, C.R.
In search of a cervix. Proc.Ann.Elephant Workshop 10. 43-50. 1989.
Ref Type: Conference Proceeding
Langman,
V.A., Maloiy, G.M.O., 1989. Passive obligatory heterothermy of the
giraffe. J. Physiol. Lond. 415, 89.
Richter, P.
Comparative morphology of the thyroid gland of mammals: shape, size,
position, blood supply, innervation and histology. Vergleichende,
morphologische Studie an der Glandula thyreoidea der Mammalia unter
Berucksichtigung von Form, Grosse, Lage, Gefassversorgung, Innervation
und histologischem Aufbau. 1-274. 1989. Giessen, Fachbereich
Veterinarmedizin, Justus-Liebig-Universitat .
Ref Type: Thesis/Dissertation
Abstract: Literature concerning the thyroid gland in primates, rodents,
insectivores, carnivores, artiodactyles, perissodactyles, elephants,
lagomorphs, bats and other classes of mammals is reviewed.
Sreekumar, K.P., Nirmalan, G., 1989.
Mineral
composition of elephant tusks. Indian Journal of Animal Science 59,
1561-1562.
Stone, J.,
Halasz, P., 1989. Topography of the retina in the elephant Loxodonta
africana. Brain,Behavior and Evolution 34, 84-95.
Abstract: The distribution of neurones in the ganglion cell layer of the
retina of an African elephant is described. The eye was obtained
post-mortem from an infant animal, which died of an unknown disease. It
is assumed that most of the neurones observed in the ganglion cell layer
are ganglion cells. Ganglion cells concentrate along a horizontal axis
extending across the retina inferior to the optic disc, as in the visual
streak described in the retina of many mammals. They also concentrate in
the upper temporal retina, in a pattern distinctive to elephants. We
suggest that this latter concentration has evolved to monitor the
animal's trunk. Features of the eye, including its size, orientation and
fundal pigmentation, are also described.
Balke, J.M.E.,
Boever, W.J., Ellersieck, M.R., Seal, U.S., Smith, D.A., 1988. Anatomy
of the reproductive tract of the female African elephant (Loxodonta
africana) with reference to development of techniques for artificial
breeding. Journal of Reproduction and Fertility 84, 485-492.
Abstract: Complete reproductive tracts of 30 female African elephants
(5-53 years), obtained during a population reduction procedure, were
examined. The reproductive tracts were palpated in situ via the
urogenital canal. A plastic speculum (1.3 X 170 cm) was introduced into
the canal and dye was injected to simulate the procedure for artificial
insemination. The lengths of the reproductive tracts (from the vulva to
the ovary) ranged from 120 to 358 cm. The length increased with the
size and age of the animal. There was a membranous constriction
(hymen) with an orifice, <2cm in diameter, between the urogenital canal
and the vagina, in 4 primigravid and in all 13 nulliparous elephants.
The vaginal orifice of 13 multiparous elephants consisted of ragged
folds of mucous membrane surrounding a single opening, 5-19cm in
diameter. The ages at first conception of 4 pregnant elephants with
intact hymenal membranes were 10, 12, 13 and 14 years. The hymen was
not penetrated as a result of intromission and therefore the site of
ejaculation would have been in the urogenital canal of the 4 primigravid
elephants.
Balke, J.M.E.,
Barker, I.K., Hackenberger, M.K., McManamon, R., Boever, W.J., 1988.
Reproductive anatomy of three nulliparous Asian elephants: the
development of artificial breeding techniques. Zoo Biology 7,
99-113.
Abstract: Detailed gross examinations of the reproductive tracts of
three mature female nulliparous Asian elephants were conducted to
develop artificial insemination (AI) techniques. Of primary concern was
the determination of length characteristics and the size and
configuration of the foramina between segments of the tract. The
elephants were 13, 28, and 40 years of age and had been maintained in
captivity for most of their lives. One elephant died naturally and two
were euthanized for health reasons. The reproductive tracts of two of
the elephants were manually palpated in situ via the urogenital
canal. A fibreoptoscope was used to visualize the internal structures
of the terminal reproductive tract of one elephant and to deposit dye
into the vagina. The reproductive organs were removed from the body
cavity, dissected, measured, and photographed. The major anatomical
obstacles to overcome for standard AI procedures (the passage of an AI
pipette into the reproductive tract) were the length of the urogenital
canal (85-97 cm), the constriction at the urogenital-vaginal junction,
and the tight cervix. The reproductive anatomy was compared to that of
previous dissections reported in the literature.
Crelin, E.S.,
1988. Ligament of the head of the femur in the orangutan and Indian
elephant. The Yale Journal of Biology and Medicine 61, 383-389.
Abstract: A literature search revealed that for over 100 years there has
been a consensus that the ligament of the head of the femur (LHF) is
absent in the orangutan and elephant. A dissection of the hip joints of
an adult orangutan and an adult Indian elephant exposed, in each joint,
a robust LHF that is functionally important. These LHFs are easily
overlooked during a cursory examination of the hip joints because of the
way they differ from the human LHF.
Grussen, B.
Comparative survey of all literature findings about the anatomy of
Indian and African elephants as a basis for practicing veterinary
surgeons. Vergleichende Zusammenstellung der Literaturbefunde uber die
Anatomie des Indischen und Afrikanischen Elefanten als Grundlage fur
tierartzliches Handeln. 1-276. 1988. Hanover.
Ref Type: Report
Henry, R.W.,
Orosz, S.E., 1988. The muscles of the crus of the African elephant
(Loxodonta africana). Anatomia Histologia Embryologia. 17, 370.
Raubenheimer,
E.J., Dauth, J., Dreyer, M.J., de Vos, V., 1988. Parotid salivary gland
of the African elephant (Loxodonta africana): structure and composition
of saliva. Journal of the South African Veterinary Medical Association
59, 184-187.
Abstract: Specimens from parotid salivary glands of full-grown elephant
(Loxodonta africana) a (n=6) and saliva aspirated from their main
excretory ducts were examined macroscopically and microscopically and
analyzed biochemically. The composition of the saliva was compared to
that of the blood. The parotids (n=12; mean = 7.4 kg) are homocrine and
of a seromucous nature. Myoepithelial cells are well-developed along
intercalated ducts and their processes extend to proximal portions of
allied acini. The saliva is hypotonic and contains relatively low
concentrations of sodium and glucose and high concentrations of
potassium, urea, calcium and phosphorus. Absence of detectable levels of
alpha-amylase negates a digestive role and the voluminous secrete
evidently aids swallowing by moisturizing and lubricating the large mass
of ingested leaves, grass and bark.
Easa, P.S.,
1987. Chemical composition of the temporal gland secretion of an Asian
elephant (Elephas maximus). Elephant 2(3), 67-68.
Abstract: The non-volatile chemical constituents of a temporal gland
secretion of a male Asian elephant are reported for the first time, and
they seem to be different, in part, from those of African elephant.
Fischer,
M.S., 1987. The trunk of elephants. Zeitschrift fur Saugetierkunde 52,
262-263.
Fischer,
M.S., Trautmann, U., 1987. Fetuses of African elephants (Loxodonta
africana) in photographs. Elephant 2, 40-45.
Abstract: Noticing that almost nothing has been published on the early
ontogenetic development in elephants, we want to start to fill this gap
by presenting pictures of elephant fetuses. All fetuses are African
elephants (Loxodonta africana). Unfortunately, we do not know the
age of the fetuses except for that largest one whichis about 8 months
old. All specimens were fixated in 4% formalin. The legends will point
to the peculiarities in the external morphology of each fetus.
Hackenberger,
M.K. Diet digestibilities and ingesta transit times of captive Asian (Elephas
maximus) & African (Loxodonta africana) elephants. 1987.
Guelph, University of Guelph.
Ref Type: Thesis/Dissertation
Haug, H.,
1987. Brain sizes, surfaces, and neuronal sizes of the cortex cerebri: a
stereological investigation of man and his variability and a comparison
with some mammals (primates, whales, marsupials, insectivores, and one
elephant). American Journal of Anatomy 180, 126-142.
Abstract: This study deals with the stereological estimation of
macroscopic sizes of brain and cortex, i.e., volume, surface, and
folding, and of microscopic neuronal sizes, i.e., density, mean size,
size distribution, and number of neurons. The results show that the
degree of variability in man amounts to about 15%. A decrease in volume
of the different gray structures can be observed in man after the age of
65 years. The surface, folding index, and length of convolution do not
alter with aging. The comparison with mammals of various sizes allows
the conclusion that there is a high correlation to brain size for nearly
all macroscopic values. Man and elephant, however, have a cortical
surface which is, in comparison with whales, relatively small. In
contrast, whales have very small cortices compared with man. At the
cytoarchitectonic level, the neuronal density has a correlation to brain
size. Contrary to other mammals, the primates and man have a high
fraction of small granular neurons, especially in layer 4. The
assumption that the number of cortical neurons beneath a given surface
area of cortex is the same in all mammals cannot be verified, especially
in those with large brains. The allometric connection between brain size
and parameters is not valid for all measurements (e.g., thickness of
cortex, mean size of neurons, perikaryal size distribution, and glial
density). Yet some other measurements are well correlated.
Lillywhite,
H.B., Stein, B.R., 1987. Surface sculpturing and water retention of
elephant skin. Journal of Zoology (Lond) 211, 727-734.
Sharma, V.S.,
Traylor, T.G., Gardiner, R., Mizukami, H., 1987. Reaction of nitric
oxide with heme proteins and model compounds of hemoglobin. Biochemistry
26, 3837-3843.
Abstract: Rates for the reaction of nitric oxide with several ferric
heme proteins and model compounds have been measured. The NO combination
rates are markedly affected by the presence or absence of distal
histidine. Elephant myoglobin in which the E7 distal histidine has been
replaced by glutamine reacts with NO 500-1000 times faster than do the
native hemoglobins or myoglobins. By contrast, there is no difference in
the CO combination rate constants of sperm whale and elephant myoglobins.
Studies on ferric model compounds for the R and T states of hemoglobin
indicate that their NO combination rate constants are similar to those
observed for the combination of CO with the corresponding ferro
derivatives. The last observation suggests that the presence of an axial
water molecule at the ligand binding site of ferric hemoglobin A
prevents it from exhibiting significant cooperativity in its reactions
with NO.
Hackenberger,
M.K., Burton, J.H., Atkinson, J.L., Dickson, K.M. Rate of ingesta
passage within captive African elephants (Loxodonta africana).
Proc.Ann.Elephant Workshop. 7, 48-58. 1986.
Ref Type: Conference Proceeding
Jongeward,
K.A., Marsters, J.C., Mitchell, M.J., Magde, D., Sharma, V.S., 1986.
Picosecond geminate recombination of nitrosylmyoglobins. Biochem.
Biophys. Res. Commun. 140, 962-966.
Abstract: The kinetics of NO geminate recombination to sperm whale and
elephant myoglobins has been studied on the picosecond time scale using
an amplified colliding-pulse mode-locked ring dye laser. The dynamics of
ligand rebinding are shown to be affected by the distal structure of the
protein surrounding the heme pocket.
Mariappa, D.,
1986. Anatomy and Histology of the Indian Elephant. Indira Publishing
House, Oak Park, MI.
Abstract: This book deals with all aspects of gross anatomy of the
Indian elephant. The chapter on histology covers 35 organs. Apart from
detailed information on the anatomy and histology of the Indian
elephant, the book provides information on many other species of mammals
to cater to the needs of veterinarians and comparative anatomists.
contemporary thoughts on phylogeny of elephants are also discussed in
the introduction.
Meijler, F.L., van der Tweel, L.H., 1986.
Electrocardigrams of 10 elephants and a killer whale in Harderwijk. Ned
Tijdschr Geneeskd 130, 2344-2348.
Mizukami, H.,
Bartnicki, D.E., 1986. Unusual myoglobin of elephant. Elephant 2,
80-81.
Abstract: Myoglobins are proteins found in muscle fibers and they store
and carry oxygen. They also bind carbon monoxide (CO). Myoglobins of
Loxodonta africana and Elephas maximus are different from
myoglobins of most other animals. Most significantly, elephant
myoglobins react with CO nearly eight times more strongly than other
myoglobins. This means that elephants housed close to expressways
(where emission of CO from motor vehicles is greatest) would be affected
by the toxic gas more than other animals would. On the other hand,
elephant myoglobin resists oxidation to a greater extent and, thus, is
more stable to the actions of certain toxins.
Mordenti, J.,
1986. Man versus beast: pharmacokinetic scaling in mammals. J Pharm Sci
75, 1028-1040.
Abstract: Land mammals range in size from the 3-g shrew to the 3000-kg
elephant. Despite this 10(6) range in weight, most land mammals have
similar anatomy, physiology, biochemistry, and cellular structure. This
similarity has allowed interspecies scaling of physiologic properties
such as heart rate, blood flow, blood volume, organ size, and longevity.
The equation that is the basis for scaling physiologic properties among
mammals is the power equation Y = aWb, where Y is the physiologic
variable of interest, W is body weight, and log a is the y-intercept and
b is the slope obtained from the plot of log Y versus log W. Animals
commonly used in preclinical drug studies (i.e., mice, rats, rabbits,
monkeys, and dogs) do not eliminate drugs at the same rate that humans
eliminate drugs; small mammals usually eliminate drugs faster than large
mammals. Since drug elimination is intimately associated with
physiologic properties that are well described among species, it seems
reasonable to surmise that drug elimination can be scaled among mammals.
Analysis of drug pharmacokinetics in numerous species demonstrates that
drug elimination among species is predictable and, in general, obeys the
power equation Y = aWb. Early papers on interspecies pharmacokinetic
scaling normalized the x- and y-axes to illustrate the
superimpossibility of pharmacokinetic curves from different species.
More recently, the x- and y-axes have been left in the common units of
concentration and time, and individual pharmacokinetic variables have
been adjusted to predict pharmacokinetic profiles in an untested
species, usually humans.
Rasmussen, L.E., Schmidt, M.J., Daves, G.D., 1986.
Chemical
communication among Asian elephants. In: Duvall, D., Silverstein, M.,
Muller-Schwarze, D. (Eds.), Chemical Signals in Vertebrates:
Evolutionary, Ecological, and Comparative Aspects. Plenum Press, pp.
627-646.
Yu, N.T.,
Thompson, H.M., Mizukami, H., Gersonde, K., 1986. The cobalt-nitrosyl
stretching vibration as a sensitive resonance Raman probe for distal
histidine-nitrosyl interaction in monomeric hemoglobins. Eur. J Biochem.
159, 129-132.
Abstract: The Co-NO stretching vibration has been assigned in the
resonance Raman spectra of various cobalt-substituted monomeric
hemoglobins by employing isotope-labeling of nitrosyl (14N16O, 15N16O,
14N18O). Monomeric hemoglobins with a distal histidine (sperm whale
myoglobin and leghemoglobin) exhibit this vibration at 573-575 cm-1,
whereas hemoglobins without distal histidine (elephant myoglobin and
insect hemoglobin from Chironomus thummi thummi, CTT III) show this
vibration in the range of 553-558 cm- 1. The Fe-NO stretching vibration
which occurs in the range of 554-556 cm-1 does not reflect the distal
histidine-ligand interaction. Therefore, the Co-NO moiety which is
isoelectronic with the Fe-O2 moiety is a good monitor for distal effects
on the exogenous ligand of hemoglobins, especially due to the fact that
in hemoglobins with distal histidine the Fe-O2 stretching vibration
(567-572 cm-1) is similar to the Co-NO stretching vibration
Acharjyo, L.N.,
Patnaik, S.K., 1985. Appearance of tusks in male Indian elephants (Elephas
maximus). Pranikee 6, 86-87.
Alexander,
R.M., 1985. The maximum forces exerted by animals. J Exp Biol 115,
231-238.
Abstract: This paper reviews the maximum forces exerted by animals in a
wide range of activities including running, jumping, swimming and
biting. Most of the data refer to vertebrates and arthropods, ranging in
size from 0.5-mg fleas to 3-tonne elephants. Maximum forces exerted on
the environment give values of (force/body weight) which lie, in most
cases, between 0.5 body mass-1/3 (kg) and 20 body mass-1/3. Maximum
forces exerted by major muscle groups give values of (force/body weight)
in most cases between 10 body mass-1/3 and 50 body mass-1/3.
Croner, L.J.,
Wainwright, S.A. Elephant trunks: morphology and motion. American
Zoologist 25[4], 12A. 1985.
Ref Type: Abstract
Abstract: Full Text. Soft tissue appendages are biomechanically
interesting because they utilize mechanical principles different from
those used in appendages with bony frameworks, and because they are
versatile. An elephant's trunk is a long tapering structure, nearly
circular in cross-section, pierced by two nostrils running up its
center, and consisting entirely of soft tissue. Investigation of an
embalmed trunk of an Asian elephant confirms that it has four distinct
muscle masses -- a radial, a longitudinal, and two oblique layers.
Analysis of films taken of an elephant as it lifted a payload with the
tip of its trunk indicates that the trunk is capable of shortening at
least 30% of its maximum length, and that it has three sections, each of
which shortens at a predictable time during a lift. Work in progress
analyzes the sequential strain patterns at different parts of a trunk
during the performance of other tasks.
Hildebrand,
M., Hurley, J.P., 1985. Energy of the oscillating legs of a fast-moving
cheetah, pronghorn, jackrabbit, and elephant. J. Morphol. 184,
23-31.
Abstract: Lifelike models of the oscillating legs treated as
three-segment systems show the course of kinetic and potential energy
over the locomotor cycle for a cheetah, pronghorn, jackrabbit, and
elephant running at speeds approaching their maxima. The models can be
adjusted to eliminate differences among the animals in time intervals,
mass or length of limb, and joint angles. This facilitates analysis of
the influence on total energy of each of these variables and of the
distribution of mass among leg segments. Fast-cycling legs of the
carnivore type have significantly more energy than those of the hoofed
type. This may contribute to the lesser endurance that is usual for
carnivores that hunt using a high-speed dash
Kerr, E.A.,
Yu, N.T., Bartnicki, D.E., Mizukami, H., 1985. Resonance raman studies
of CO and O2 binding to elephant myoglobin (distal
His(E7)----Gln). Journal of Biological Chemistry 260, 8360-8365.
Abstract: Carbon monoxide and dioxygen were employed as resonance Raman-
visible ligands for probing the nature of the heme-binding site in
elephant myoglobin, which has glutamine in the distal position (E7)
instead of the usual histidine. The distal histidine (E7) residue has
been thought to be responsible for weakening carbon monoxide binding to
hemoproteins. It is of interest to see how the His(E7)----Gln
replacement affects such parameters as nu(Fe-N epsilon), nu(Fe-CO),
delta(Fe-C-O), nu(C-O), delta(Fe-O-O), and nu(O-O) vibrational
frequencies and relative intensities. Elephant myoglobin has a CO
affinity approximately 6 times higher than that for human/sperm whale
myoglobin (Mb). If this enhanced affinity were solely due to the removal
of some of the steric hindrance that normally tilts the CO off the heme
axis, one would expect the nu(Fe-CO) frequency to decrease and the nu(C-O)
frequency to increase relative to the corresponding values in sperm
whale Mb. However, the opposite was found. In addition, strong
enhancement of the Fe-C-O bending mode was observed. These results
suggest that the Fe-C-O linkage remains distorted. In elephant Mb, new
interactions resulting from the conformational change accompanying
ligand binding may be responsible for the increased CO binding. Similar
spectra were obtained for elephant and sperm whale oxymyoglobin. This
suggests that the interactions of bound O2 are not markedly affected by
the glutamine replacement
Meijler, F.L.,
1985. Atrioventricular conduction versus heart size from mouse to whale.
J Am Coll Cardiol 5 (Pt 2), 363-365.
Scarborough,
J., 1985. Galen's dissection of the elephant. Korot 8, 123-134.
Sher, A.V.,
Garutt, V.E., 1985. New data on the molar morphology of the elephants.
Doklady Acad. Nauk SSSR 285, 221-225.
Baranga, J.,
1984. The adrenal gland weights of the African elephant, Loxodonta
africana. Zeitschrift fur Saugetierkunde 49, 341-348.
Braunitzer,
G., Stangl, A., Schrank, B., Krombach, C., Weisner, H., 1984. Phosphate-haemoglobin
interaction. The primary structure of the haemoglobin of the African
elephant (Loxodonta africana, Proboscidea): asparagine in position 2 of
the beta-chain. Hoppe-Seyler's Z. Physiol. Chem. 365, 743-749.
Abstract: The primary structure of the haemoglobin of the African
Elephant (Loxodonta africana) is reported. The sequence was
determined by means of a sequenator. The haemoglobin differs in 26
amino acids in the alpha-chains in and 27 in the beta-chains from that
of adult human hemoglobin. The haemoglobin of the African Elephant,
like that of the Indian Elephant and the llama, has only 5 binding sites
for polyphosphate. This finding explains the low p(O2)50
value in whole blood as a result of the lower
2,3-bisphosphoglycerate-haemoglobin interaction. This is discussed in
relation to aspects of respiratory physiology; some points are also of
interest with regard to the Second Punic War and Hannibal's crossing of
the Alps.
Buys, D.,
Keogh, H.J., 1984. Notes on the microstructure of hair of the
Orycteropodidae, Elephantidae, Equidae, Suidae and Giraffidae. South
African Journal of Wildlife Research 14, 111-119.
Abstract: The microstructure of hair of seven species of African mammals
is described. Distribution notes and micrographs are presented to
assist in hair identification.
Hildebrand,
M., 1984. Rotations of the leg segments of three fast-running cursors
and an elephant. Journal of Mammalogy 65, 718-720.
Krishnamoorthi, R., La Mar, G.N., Mizukami, H., Romero, A., 1984. A
proton NMR investigation of the influence of distal glutamine on
structural and dynamic properties of elephant metmyoglobin. Journal of
Biological Chemistry 259, 265-270.
Abstract: The proton NMR spectra of metmyoglobin from the Asian
elephant, which has the replacement of glutamine for the usual distal
histidine, are reported and analyzed. In the low pH region, we detect
two interconvertible forms of the met-aquo-protein whose relative
stabilities are independent of pH, but depend strongly on both
temperature and solvent isotope composition. As the pH is raised, both
species convert to the met-hydroxy form, as found for other myoglobins.
The temperature dependence of the heme methyl shifts for both acidic
protein forms indicates essentially high spin character for the iron,
and the mean heme methyl shifts are interpreted as indicating one form
with a very slightly weaker, and the other with a significantly
stronger, axial ligand field than for the unique sperm whale met-aquo-myoglobin.
The thermodynamic data for the equilibrium between the two species are
consistent with differences of one hydrogen bond between coordinated
water and the distal glutamine. Models are proposed where one form of
the protein has not only the glutamine carboxyl oxygen acting as a
hydrogen-bond acceptor, but also the amine group. We conclude that a
distal glutamine can act both as a stronger and as a weaker
hydrogen-bond acceptor towards coordinated water than the usual distal
histidine. The relative rates of conversion of the two met-aquo-myoglobin
forms to MetMbOH is found to be consistent with the proposed structures
for the two forms.
Krishnamoorthi, R., La Mar, G.N., Mizukami, H., Romero, A., 1984. A
1H NMR comparison of the met-cyano complexes of elephant and sperm
whale myoglobin. Assignment of labile proton resonances in the heme
cavity and determination of the distal glutamine orientation from
relaxation data. Journal of Biological Chemistry 259, 8826-8831.
Abstract: The met-cyano complex of elephant myoglobin has been
investigated by high field 1H NMR spectroscopy, with special emphasis on
the use of exchangeable proton resonances in the heme cavity to obtain
structural information on the distal glutamine. Analysis of the distance
dependence of relaxation rates and the exchange behavior of the four
hyperfine shifted labile proton resonances has led to the assignment of
the proximal His-F8 ring and peptide NHs and the His-FG3 ring NH and the
distal Gln-E7 amide NH. The similar hyperfine shift patterns for both
the apparent heme resonances as well as the labile proton peaks of
conserved resonances in elephant and sperm whale met-cyano myoglobins
support very similar electronic/molecular structures for their heme
cavities. The essentially identical dipolar shifts and dipolar
relaxation times for the distal Gln-E7 side chain NH and the distal
His-E7 ring NH in sperm whale myoglobin indicate that those labile
protons occupy the same geometrical position relative to the iron and
heme plane. This geometry is consistent with the distal residue hydrogen
bonding to the coordinated ligand. The similar rates and identical
mechanisms of exchange with bulk water of the labile protons for the
three conserved residues in the elephant and sperm whale heme cavity
indicate that the dynamic stability of the proximal side of the heme
pocket is unaltered upon the substitution (His----Gln). The much slower
exchange rate (by greater than 10(4] of the distal NH in elephant
relative to sperm whale myoglobin supports the assignment of the
resonance to the intrinsically less labile amide side chain
Krishnamoorthi, R., La Mar, G.N., 1984.
Identification of the titrating group in the heme cavity of myoglobin.
Evidence for the heme-protein pi-pi interaction. Eur. J Biochem. 138,
135-140.
Abstract: The pH dependence of the proton NMR chemical shifts of met-cyano
and deoxy forms of native and reconstituted myoglobins reflects a
structural transition in the heme pocket modulated by a single proton
with pK 5.1-5.6. Comparison of this pH dependence of sperm whale and
elephant myoglobin and that of the former protein reconstituted with
esterified hemin eliminates both the distal histidine as well as the
heme propionates as the titrating residue. Reconstitution of sperm whale
met-cyano myoglobin with hemin modified at the 2,4-positions leads to a
systematic variation in the pK for the structural transition, thus
indicating the presence of a coupling between the titrating group and
the heme pi system. The results are consistent with histidine FG3
(His-FG3) being the titrating group, and a donor-acceptor pi- pi
interaction between its imidazole and the heme is proposed.
Poupa, O.,
Brix, O., 1984. Cardiac beat frequency and oxygen supply: a comparative
study. Comp Biochem Physiol A 78, 1-3.
Abstract: The length of diastole in mammals varies between approx 1 s
(elephant) and 38 ms (shrew) which makes oxygen supply in high speed
cardiac pumps in very small mammals precarious. High capillary density
and high blood P50 are reported in mammals with high frequency cardiac
cycle. Both are probably insufficient when cardiac frequency is
exceedingly high (shrew: 1000 min-1). High respiratory efficiency due to
large relative mitochondrial volume per cell (greater than 50%) seems to
be preferential solution to maintain sufficient O2-gradient. Similar
strategy, i.e. high relative cardiac mitochondrial volume was reported
in analogous situation in ice-fish (Chaenocephalus aceratus) where O2
cardiac cell supply is difficult due to the absence of hemoglobin and
cardiac myoglobin.
Rowlands, I.W.,
Weir, B.J., 1984. Mammals: non-primate eutherians. In: Lamming, G.E.
(Ed.), Marshall's physiology of reproduction. Churchill Livingstone, New
York, pp. 455-658.
Rubin, C.T.,
Lanyon, L.E., 1984. Dynamic strain similarity in vertebrates; an
alternative to allometric limb bone scaling. Journal of Theoretical
Biology 107, 321-327.
Abstract: Galileo (1638) observed that "nature cannot grow a tree nor
construct an animal beyond a certain size, while retaining the
proportions which suffice in the case of a smaller structure". However,
subsequent measurement has shown that limb bone dimensions are scaled
geometrically with body size (Alexander et al., 1979a), and that the
material properties of their constituent bone tissue are similar in
animals over a wide range of body weight (Sedlin & Hirsch, 1966; Yamada,
1970; Burstein et al., 1972; Biewener, 1982). If, as suggested in
previous scaling arguments (McMahon, 1973; Biewener, 1982), vigorous
locomotion involved the same proportional forces over a wide range of
animal size, this would create a paradox since large animals would be in
far greater danger of skeletal failure than small ones. However, in vivo
strain gauge implantations have shown that, during high speed running,
axial force as a proportion of body weight (G) in the limb bones of
animals decreases as a function of body size from 6.9 G in a 7 kg turkey
to 2.8 G in a small (130 kg) horse. Estimates of axial force in larger
animals suggest that this is further reduced to 0.8 G in a 2500 kg
elephant. Nevertheless, it appears that, regardless of animal size or
locomotory style, the peak stresses in the bones of these animals are
remarkably similar. Therefore, throughout the range of animals
considered (350 times differences in mass), we suggest that similar
safety factors to failure are maintained, not by allometrically scaling
bone dimensions, but rather by allometrically scaling the magnitude of
the peak forces applied to them during vigorous locomotion.(ABSTRACT
TRUNCATED AT 250 WORDS)
Wright, P.G.,
Luck, C.P., 1984. Do elephants need to sweat? South African Journal of
Zoology 19, 270-274.
Wright, P.G.,
1984. Why do elephants flap their ears? South African Journal of Zoology
19, 266-269.
Bartnicki, D.E., Mizukami, H., Romero-Herrera, A.E., 1983.
Interaction
of ligands with the distal glutamine in elephant myoglobin. Journal of
Biological Chemistry 258, 1599-1602.
Abstract: The effects of distal glutamine (E7) replacement in elephant
myoglobin were studied by comparing the temperature-dependent nitrosyl
electron spin resonance spectra, redox potentials, and the acid-alkaline
equilibria of elephant and human myoglobins. For myoglobins containing a
distal histidine, the nitrosyl ESR spectra do not exhibit superhyperfine
splitting until near liquid helium temperatures (Yoshimura, T., Ozaki,
T., Shintani, Y., and Watanabe, H. (1979) Arch. Biochem. Biophys. 193,
301-313). Studies presented here show that the ESR spectra of nitrosyl
elephant myoglobin exhibit 9-line superhyperfine splitting well above
liquid nitrogen temperatures, similar to the temperature profiles of
isolated heme complexes (Morse, R.H. (1980) Fed. Proc. 39, 2006). It is
concluded that the shift in the spectral equilibrium to higher
temperature indicates a diminished interaction between NO and the distal
position in elephant myoglobin. In addition, the redox potential of
elephant myoglobin was found to be nearly 100 mV greater than that of
human myoglobin, and the pKa of the acid-alkaline equilibrium (oxidized
myoglobin) was 8.5, being 0.4 unit less than that of other vertebrate
myoglobins. These different reactivities between elephant and human
myoglobins are discussed based on the nature of charge interactions
between polar ligands and distal glutamine and histidine
Clemens, E.T.,
Maloiy, G.M.O., 1983. Nutrient digestibility and gastrointestinal
electrolyte flux in the elephant and rhinoceros. Comparative
Biochemistry and Physiology [A] 75, 653-658.
Abstract: 1. Nutrient digestibility and absorption-secretion were
studied in elephants and rhinoceros. 2. Prehension and diet selection
are discussed. 3. Rhinoceros select less fiber, which may account for
their greater digestive efficiency. 4. Foregut digestion and
fermentation are most evident in the rhinoceros, while elephants
possessed greated caecal-colonic digestion. 5. Relative to rhinoceros,
elephants demonstrated greater intestinal VFA absorption and less
sodium-potassium flux.
Dmytriw, R.
Further discussion of an ankle deformity in a young African elephant at
the Indianapolis Zoo. AAZPA Annual Conference Proceedings. AAZPA Annual
Conference Proceedings , 455-458. 1983.
Ref Type: Conference Proceeding
Heath, E.,
Jeyendran, R.S., Graham, E.F., 1983. Ultrastructure of spermatozoa of
the Asiatic elephant (Elephas maximus). Zbl. Vet. Med. C. Anat.
Histol. Embryol. 12, 245-252.
Abstract: A scanning and transmission electron microscopic study of
semen collected with the aid of an artificial vagina was carried out.
The ultrastructural characteristics of Asiatic bull elephants is
compared to that of other mammalian species.
Ruedi, D.,
Kupfer, U., Girard, J., Gutzwiller, A., 1983. Untersuchungen zur
fortflanzungsphysiologie biem Afikanischen elefanten (Loxodonta
africana): Samengewihhung bei wildbullen, weitere schritte
hinsichtlich kunstlicher besamung. Erkrankungen der Zootiere 341-381.
Valente, A.,
1983. Hair structure of the woolly mammoth, Mammuthus primigenius
and the modern elephants, Elephas maximus and Loxodonta
africanus. Journal of Zoology (Lond) 199, 271-274.
Abstract: The structure of overhairs from a Wooly mammoth, Mammuthus
primigenius, 10-13 thousand years old,is compared with that of its
living relatives, Elephas maximus and Loxodonta africana.
The hair profile, cross-sectional appearance, wholemount and cuticular
scale cast of the hairs of the three species were examined and a
selected array of photographs representing the hair structure of each
species is presented. In general there is little variation between the
three species in the gross structure of the overhairs.
Wallach,
J.D., Boever, W.J., 1983. Diseases of Exotic Animals. W.B.Saunders,
Philadelphis.
Wallach,
J.D., Boever, W.J., 1983. Perissodactyla (equids, tapirs, rhinos),
Proboscidae (elephants), and Hippopotamidae (hippopotamus). In: Wallach,
J.D., Boever, W.J. (Eds.), Diseases of exotic animals. W.B. Saunders
Company, Philadelphia, pp. 761-829.
Braunitzer,
G., Jelkmann, W., Stangl, A., Schrank, B., Krombach, C., 1982.
Hemaglobins, XLVIII: the primary structure of hemoglobin of the Indian
elephant (Elephas maximus, Proboscidae): beta 2 = Asn. Hoppe.
Seylers. Z. Physiol. Chem. 363, 683-691.
Abstract: The primary structure of the hemoglobin of the Indian Elephant
(Elephas maximus) is given. The sequence was determined automatically in
a sequenator. By homologous comparison with adult human HbA, the
alpha-chains differ by 24 exchanges and the beta-chains by 27 exchanges.
Furthermore, we report p(O2)50 values with regard to altered contact
sites with 2,3- bisphosphoglycerate in Indian elephant hemoglobin. Our
findings explain the low p(O2)50 and the reduced interaction with 2,3-
bisphosphoglycerate. Elephant hemoglobin has, like that of the Llama,
only five phosphate binding sites. In addition, we have made an attempt
to relate these results to aspects of respiratory physiology. Some
implications of these biochemical and physiological results, concerning
the Second Punic War and Hannibal's Alp transition, are given.
Clemens, E.T.,
Maloiy, G.M.O., 1982. The digestive physiology of three East African
herbivores: the elephant, rhinoceros and hippopotamus. Journal of
Zoology (Lond) 198, 141-156.
Abstract: Studies were conducted to compare structural and physiological
differences in the digestive functions of three 0. species of large
ungulates; the elephant (Loxodonta africana), the Black
rhinoceros (Diceros bicornis) and the Hippopotamus (Hippopotamus
amphibius). Major differences were noted in the composition of
ingesta and the sites of bacterial fermentative activity. Comparisons
are also made as to the influence of feeding behaviour on digestive
functions, and as to the similarities of their digestive systems to that
of domestic animals.
Eltringham,
S.K., 1982. Elephants. Blandfort Books,Ltd., United Kingdom.
Foose, T.J.
Trophic strategies of ruminant versus nonruminant ungulates. 1982.
Chicago, University of Chicago.
Ref Type: Thesis/Dissertation
Hackenberger,
M.K., Atkinson, J.L. Digestibility studies with captive Asiatic and
African elephants. AAZPA Reg.Conf.Proc. 129-137. 1982.
Ref Type: Conference Proceeding
Harvey, P.H.,
1982. On rethinking allometry. Journal of Theoretical Biology 95,
37-41.
Abstract: Analysis of sets of intra-specific and inter-specific
allometric relationships reveals than the inter-specific data generally
fit an exponential model better than a linear model. The intra-specific
data seem equally suited to either model. Skewness of the data and the
effect of logarithmic transformations on correlation coefficients are
examined in the light of these findings. Inter-species data are
approximately lognormally distributed and logarithmic transformations
are necessary to produce linear relationships. As a consequence,
correlation coefficients usually increase after logarithmic
transformation of inter-species data.
Rees, P.S.,
1982. Gross assimilation efficiency and food passage time in the African
elephant. African Journal of Ecology 20, 193-198.
Abstract: The amount of food consumed and dung voided by two captive
African elephants was measured over a period of 7 days. The mean gross
assimilation efficiency of the two elephants was calculated to be
22.4%. The food passage time was 21.4 and 46 h for one elephant.
Previous estimates of food consumption by wild elephants, based on an
earlier, higher estimate of assimilation efficiency, are considered to
be too high and have been recalculated.
Shoshani, J.,
Alder, R., Andrews, K., Baccala, M.J., Barbish, A., Barry, S., Battiata,
R., Bedore, M.P., Berbenchuk, S.A., Bielaczyc, R., Booth, G., Bozarth,
N., Bulgarelli, M.A., Church, I., Cosgriff, J.W.Jr., Crowe, H., DeFauw,
S.L., Denes, L., Efthyvoulidis, E., Ekstrom, M., Engelhard, J.G.,
English, P., Fairchild, D.Jr., Fisher, C., Frahm, K., Frederick, D.,
Fried, J., Gaskins, T., Gatt, J., Gentles, W., Goshgarian, H.G.,
Grabowski, S., Haase, D., Hajj, K., Hall, G., Hawkins, D., Heberer, C.,
Helinski, A., Henry, S.R., Heyka, C., Hurt, M., Kemppainen, M., Kendra,
C., Koenig, J., Konarske, P., Konwinski, S., Kopacz, S., Lakits, V.T.,
Jr., Lash, S.S., Laughlin, D.C., Meyers, S., Mizeres, N.J., Morehead,
K.M., Muraski, A., Murphy, S., Niebala, J., Overbeck, G., Powitz, R.,
Rafols, J.A., Raymer, S.L., Rezzonica, L., Rossmoore, H.W., Sabo, D.,
Schwikert, P.J., Shy, E., Skoney, J., Smith, D., Spodarek, K.L., Sujdak,
P.J., Tarrant, T., Thielman, R., Tisch, F., Wolowicz, L., Williams, J.,
Yehiel, D., 1982. On the dissection of a female Asian elephant (Elephas
maximus maximus Linnaeus, 1758) and data from other elephants.
Elephant 2, 3-93.
Abstract: A 46-year-old female Asian elephant (Elephas maximus
maximus Linnaeus, 1758), named "Iki", died on July 8, 1980, at the
Ringling Brothers and Barnum & Bailey Circus, Circus World, Haines City,
Florida, USA. She was transported to Detroit and was dissected by the
Elephant Interest Group (EIG) and friends, Department of Biological
Sciences, Wayne State University. The purpose of this continuing study
has been to collect data supplemental to that of previous workers, and
to enrich knowledge of elephant anatomy, particularly in areas not
thoroughly investigated in the past. Some of these findings were
compared to those observed in other elephants: "Shirley", "Tulsa", and
"Toose" and to the organs of "Ole Diamond" and "Hazel" (see Appendix
II).
Jones, R.C.,
Brosnan, M.F., 1981. Studies of the deferent ducts from the testis of
the African elephant, Loxodonta africana. I. Structural
differentiation. Journal of Anatomy 132, 371-386.
Jones, R.C.,
Holt, W.V., 1981. Studies of the deferent ducts from the testis of the
African elephant, Loxodonta africana. III. Ultrastructure and
cytochemistry of the ductuli efferentes. J Anat 133 (Pt 3),
247-255.
Abstract: The epithelium of the ductuli efferentes is composed of
ciliated, principal, halo and basal cells. The supranuclear cytoplasm of
ciliated cells is penetrated by particularly long cilial rootlets which
are surrounded by numerous elongate mitochondria. Microtubules are
arranged along the longitudinal axis of the cells. The spaces between
the microvilli of principal cells form canaliculi which penetrate the
apical cytoplasm and appear to be involved in endocytotic activity. The
supranuclear cytoplasm contains oval mitochondria and numerous vacuoles.
Both ciliated and principal cells contain poorly developed Golgi and
endoplasmic reticulum, but numerous supranuclear dense bodies are
usually present. Supranuclear and basal accumulations of dense bodies
were identified as lipofuscin; they were the source of brown
pigmentation in the proximal two thirds of the ductuli efferentes. The
halo cells were probably macrophages. They occurred quite frequently and
contained crescent shaped nuclei and large
accumulations of lipofuscin material.
Paladino, F.V.,
Spotila, J.R., Pendergast, D. Respiratory variables of Indian and
African elephants. American Zoologist 21[4], 1043. 1981.
Ref Type: Abstract
Abstract: Full Text. End expiratory gas samples of Indian and African
Elephants were analyzed for O2 and CO2. At rest
the mean measured O2 deficit for Adult Indian Elephants was
3.0% O2 with a CO2 increment of 3.18% CO2
(R.Q.=1.06). Immediately after 10 minutes of exercise the 3 adult Indian
Elephants had a mean 4.75% O2 deficit and 5.2% CO2
increment (R.Q.=1.1). One juvenile Indian Elephant had a resting O2
deficit of 4.12% and a 4.6% CO2 increment (R.Q.=1.12)
indicating a slightly higher metabolic rate. One adult African Elephant
had a resting 4.2% O2 deficit and a 4.33% CO2
increment (R.Q.=1.03).
Van
Hoven, W., Prins, R.A., Lankhorst, A., 1981.
Fermentative
digestion in the African elephant. South African Journal of Wildlife
Research 11, 78-86.
Abstract: In an investigation into the nature of gastrointestinal
fermentation in adult African elephant ( Loxodonta africana L.),
the following parameters were determined in various intestinal
compartments: volume, pH, concentrations of sugars, bicarbonate,
volatile fatty acids (VFA), lactic acid and protozoa. The composition
of the digesta was determined by the proximate analysis and the
procedure of van Soest. Concentrations of minerals were analyzed in the
caecal and colonic fluids. Rates of gas production, composition of the
fermentation gas, rates of lactate breakdown, and cellulolytic and
amylolytic activity in the gut contents were measured using in vitro
incubations. The results show that there is microbial fermentation of
sugars, starch and protein from the food in different compartments of
the gastrointestinal tract, with most activity occurring in the caecum
and colon. Cellulose digestion, however, is surprisingly small. Despite
the low rate of fermentation in the gut the elephant is likely to cover
a large part of its energy requirement from the metabolism of VFA
arising from the hindgut fermentation. In English with Afrikaans
summary.
Fowler, M.E.,
1980. Hoof, claw, and nail problems in nondomestic animals. Journal of
the American Veterinary Medical Association 177, 885-893.
Holt, W.V.,
Jones, R.C., Skinner, J.D., 1980. Studies of the deferent ducts from the
testis of the African elephant, Loxodonta africana. II.
Histochemistry of the epididymis. Journal of Anatomy 130,
367-379.
Abstract: The three main segments of the elephant epididymis were
examined for the occurrence, in the spermatozoa and lining epithelium,
of carbohydrates, neutral lipids and phospholipids, ATPase, alkaline
phosphatase, succinic dehydrogenase, glucose-6-phosphate dehydrogenase,
diaphorases, hydroxysteroid dehydrogenases, acid phosphatase and
non-specific esterase. The most distinct feature of the carbohydrate
content of the epididymis was a layer of acidic, alcian blue-positive
glycoprotein over the luminal surface of the epithelium, particularly in
the terminal segment. PAS-positive, diastase-resistant inclusions were
also found throughout the epididymis. Neutral lipid occurred as droplets
above and below the nucleus in the epithelium of the middle segment, and
as supranuclear accumulations in the terminal segment. All the enzymes
except the steroid dehydrogenases were detected in the epididymal
epithelium, and all except the steroid dehydrogenases and acid
phosphatase were detected in the spermatozoa. There was considerable
variation in the intensity of the cytochemical reactions in the
epithelium, but not in the spermatozoa, in different regions of the
epididymis. In general, the enzymes involved in active transport showed
strongest reactions in the initial and terminal segments, the reactions
in the stereocilia being the most intense. The enzymes involved in
energy metabolism showed strongest reactions in the middle and terminal
segments, with the activity being fairly evenly distributed throughout
the cytoplasm of the principal cells. However, the two lysosomal enzymes
which were studied showed quite different distributions: the reactions
for acid phosphatas were strongest in the initial and middle segments,
whilst the reactions for non-specific esterase were strongest in the
middle and terminal segments. It is suggested that the initial segment
is involved in absorptive and anabolic activity, the middle segment in
anabolic activity, and the terminal segment (where spermatozoa are
stored ready for ejaculation) in considerable metabolic activity and
active transport of substrates across the epithelium.
Hooijer,
D.A., 1980. Remarks on the dentition and tooth replacement in elephants.
Netherlands Journal of Zoology 30, 510-515.
Abstract: It has often been stated that in the modern elephant there is
a special kind of forward-moving tooth succession, which would have come
in the place of the ordinary vertical tooth replacement in other
mammals. This is a mistaken view. In the modern elephant with its
disproportionately large cheek teeth vertical tooth replacement has been
eliminated because of lack of space, whereas the "horizontal tooth
replacement" is more apparent than real. It is basically the same
phenomenon that is known in many mammals, Man included, as "closing of
the ranks", teeth drifting together so as to assure continuous contact
within the functional series. The "horizontal replacement" is not a
substitute for the vertical, and is not peculiar to the elephant.
Johnson, D.L.,
1980. Problems in the Land Vertebrate Zoogeography of Certain Islands
and the Swimming Powers of Elephants. Journal of Biogeography 7,
383-398.
Abstract: The presence of fossil elephants on certain islands off
California, in the Mediterranean, in Indonesia, and off China has led to
two widely accepted assumptions: (1) that elephants, being poor
swimmers, could not have swum to the islands and therefore must have
walked to them, which indicates that (2) land bridges once joined the
islands to the mainland. These two assumptions have profoundly
influenced various insular biogeographic and geologic reconstructions on
and around these islands. New evidence, however, shows unequivocally
that living elephants are excellent distance swimmers. They swim in a
lunging, porpoise-like fashion while using their trunk as a snorkel.
Elephant swimming speeds have been measured up to 2.70 km/h, and maximum
distances estimated at 48 km. Their chief motives for swimming seem to
be that they can see the islands and smell food on them. Because
elephants are excellent distance swimmers, we must re-appraise the
origin of land vertebrates on all the islands that held elephants, as
well as reappraise the geologic reconstructions that assumed land
bridges once connected these islands to the mainland.
1979. "Motty"
-- Birth of an African/Asian elephant at Chester Zoo. Elephant 1,
36-40.
Alexander,
R.M., Jayes, A.S., Maloiy, G.M.O., Wathuta, E.M., 1979. Allometry of the
limb bones of mammals from shrews (Sorex) to elephants (Loxodonta).
Journal of Zoology (Lond) 189, 305-314.
Abstract: Measurements have been made of the principal leg bones of 37
species representing almost the full range of sizes of terrestrial
mammals. The lengths of corresponding bones tend to be proportional to
(body mass)0.35 and the diameters to (body mass)0.36
except in the family Bovidae in which the exponents for length are much
nearer the value of 0.25 predicted by McMahon's (1973) theory of elastic
similarity. Comparisons are made between mammals of similar size
belonging to different orders.
Alexander,
R.M., Maloiy, G.M.O., Hunter, B., Jayes, A.S., Nturibi, J., 1979.
Mechanical stresses in fast locomotion of buffalo (Syncerus caffer)
and elephant (Loxodonta africana). Journal of Zoology (Lond) 189,
135-144.
Abstract: Films of buffalo and elephant running, and detailed
measurements on dissected legs, have been used to estimate the maximum
stresses which occur in locomotion, in certain muscles, tendons and
bones. These stresses are similar to stresses previously determined for
some other, smaller mammals.
Folk, G.E.,
Folk, M.A., 1979. Physiology of large mammals by implanted radio
capsules. In: Amlaner, Jr.C.J., Macdonald, D.W. (Eds.), A handbook on
biotelemetry and radio tracking. Pergamon Press, New York, pp. 33-43.
Ommer, P.A.,
Radhakrishnan, K. Anatomical peculiarties of elephants. State Level
Workshop on Elephants. 13-19. 1979. India, College of Veterinary and
Animal Sicences, Kerala Agricultural University.
Ref Type: Conference Proceeding
Vendan, C.,
1979. The trunk, hand of the elephant. Study of its prehensile and
tactile termination. Ann. Chir. Plast. 24, 392-396.
Whitehill,
N., 1979. Suggested mechanical model of elephant trunk muscle tissue and
its sheer conjecture. Elephant 1, 34-35.
Adams, J.,
Garcia III, A., Foote, C.S., 1978. Some chemical constituents of the
secretion from the temporal gland of the African elephant (Loxodonta
africana). Journal of Chemical Ecology 4, 17-25.
Abstract: The temporal glands of African elephants were examined
microscopically and histologically, and were found to be modified
apocrine sweat glands. The secretion from thse glands was analyzed by
gas chromotography and mass spectrometry, and some of the major volatile
components have been identified as phenol and m- and p-cresol.
Hass, G.,
1978. Behavioural disorders in a female Indian elephant (Elephas
maximus bengalensis) with bony structures on the intermediofacial
and statoacoustic nerves. Zoologische Garten 48(4,S.), 297-298.
Kozawa, Y.,
1978. Comparative histology of proboscidean molar enamel. Kokubyo Gakkai
Zasshi 45, 585-606.
De Jong,
W.W., Nuy-Terwindt, E.C., Versteeg, M., 1977. Primary structures of
alpha crystallin A chains of elephant, whale, hyrax and rhinoceros.
Biochim. Biophys. Acta 491, 573-580.
Abstract: As part of a study of the evolutionary development of the eye
lens protein alpha-crystallin the 173 residue A chain of this protein
has been studied in elephant, whale, hyrax and rhinoceros. The primary
sturctures were inferred mainly from amino acid compositions of peptides
obtained by enzymatic digestions and CNBr cleavage. The positions of
substitutions, as compared to known bovine A chain, were confirmed by
Edman degradation. In accordance with the previously observed slow rate
of evolution of the A chain only a small number of substitutions were
found among these species. Elephant and hyrax share a number of unique
substitutions, strongly indicating a common ancestry of these two
species within the mammalian class.
Shoshani, J.,
1977. General information on elephants with emphasis on tusks. Elephant
1, 20-34.
Bartels, H.,
1976. Comparative aspects of respiration and circulation in mammals.
Pneumonologie Supplement 1-9.
Dropp, J.J.,
1976. Mast cells in mammalian brain. Acta Anat (Basel) 94, 1-21.
Abstract: Mast cells, which had until recently been believed to be not
present in the mammalian brain, were studied in the brains of 29
mammalian species. Although there was considerable intraspecific and
interspecific variation, mast cells were most numerous within the
leptomeninges (especially in those overlying the cerebrum and the dorsal
thalamus - most rodents, most carnivores, chimpanzees, squirrel monkeys
and elephant), the cerebral cortex (most rodents, tiger, fox,
chimpanzee, tarsier, and elephant) and in many nuclei of the dorsal
thalamus (most rodents, tiger, lion, and fox). In some mammals, mast
cells were also numerous in the stroma of the telencephalic choroid
plexuses (chimpanzee, squirrel monkey), the putamen and the claustrum
(chimpanzee), the subfornical organ (pack rat, tiger, chimpanzee), the
olfactory peduncles (hooded rat, albino rat), the stroma of the
diencephalic choroid plexus (lion, chimpanzee, squirrel monkey), the
pineal organ (chimpanzee, squirrel monkey), some nuclei of the
hypothalamus (tiger), the infundibulum (hooded rat, tiger, fox) the area
postrema (pack rat, chinchilla, lion, spider monkey, chimpanzee, fox)
and some nuclei and tracts of the metencephalon and the myelencephalon
(tiger). Neither the sex of the animal nor electrolytic lesions made in
the brains of some of the animals at various times prior to sacrifice
appeared to effect the number and the distribution of mast cells.
Age-related changes in mast cell number and distribution were detected
in the albino rat.
Estes, J.A.,
Buss, I.O., 1976. Microanatomical structure and development of the
African elephants' temporal gland. Mammalia 40, 429-436.
Abstract: The microanatomical structure of temporal glands from thirteen
adult African elephants and one fetus, approximately five months old,
were examined. The temporal gland consists of compound tubular alveoli
interspersed within a loose connective tissue matrix, which is separated
into numerous lobes by septa of dense connective tissue. Structurally
the gland is nearly identical with the temporal gland of the Asiatic
elephant. Metachromatic granules are numerous around the lumenal
border of glandular cells suggesting an acid mucopolysaccharide
secretory product. Fibroblasts and macrophages are numerous along with
occasional plasma cells and mast cells in the loose connective tissue
matrix. Mallory's azan indicated that glandular cytoplasm adjacent to
the basement membrane was acidophilic whereas the secretion was always
basophilic. Frozen sections of temporal glands stained with oil red-O
confirmed the presence of lipids throughout the glandular cytoplasm.
The presence of myoepithelial cells was suggested, but not confirmed.
Histogenesis of the temporal gland at the five month fetal stage
indicates epithelial primordia forming downward projections into the
connective tissue. Development at this point is similar to that of
mammary gland further confirming a common origin with apocrine sweat
glands.
Nevill, G.F.,
Crompton, W.G., Hennessy, M.A., Watson, P.F., 1976. Instrumentation for
artificial insemination in the African elephant Loxodonta africana.
International Zoo Yearbook 16, 166-171.
1975. Sisson
and Grossman's the anatomy of the domestic animals. W.B. Saunders
Company, Philadelphia.
Caldwell, J.,
French, M.R., Idle, J.R., Renwick, A.G., Bassir, O., Williams, R.T.,
1975. Conjugation of foreign compounds in the elephant and hyaena. FEBS
Lett 60, 391-395.
Cave, A.J.E.,
1975. Postcava structure in the elephant and rhinoceros. Journal of
Zoology (Lond) 176, 559-565.
Abstract: The mammalian postcava is vulnerable to lumen diminution or
collapse under sudden increase of intra-abdominal pressure. Against
such collapse its dorsal wall receives an extrinsic protection from the
abdominal parietes. Its ventral wall, however, develops an intrinsic
protective mechanism in the form of a specialization of its histological
architecture. This specialization is most readily noticeable in
large-bodied mammals and the details of it are given for four such
forms, viz., Asiatic elephant (Elephas), Sumatran rhinoceros (Didermocerus),
Black rhinoceros (Diceros) and White rhinoceros (Ceratotherium).
Elder, W.H.,
Rodgers, D.H., 1975. Body temperature in the African elephant as related
to ambient temperature. Mammalia 39, 395-399.
Hiley, P.G.,
1975. How the elephant keeps its cool. Natural History 84, 34-41.
Huber, D.,
Kardum, P., Gomercic, H., 1975. Blood vessels of the fore limb in Indian
elephant, Elephas maximus. Veterinarski Arhiv 45, 311-320.
Markowitz,
H., Schmidt, M., Nadal, L., Squier, L., 1975. Do elephants ever forget?
Journal of Applied Behavior Analysis 8, 333-335.
Abstract: The adult female elephants (Elephas maximus) were
tested on a light-dark discrimination problem with an eight year
intertrial interval. The first subject took only six minutes to reach
criterion and made only 2 errors, suggesting remarkable retention. The
other 2 subjects were identified to have visual anomalies which would
have gone undetected without this research.
McCullagh,
K.G., 1975. Arteriosclerosis in the African elephant: Part 2. Medial
sclerosis. Atherosclerosis 21, 37-59.
Abstract: Summary: A type of spontaneous arteriosclerosis, described as
medial sclerosis and quite distinct from atherosclerosis, was found in
the aortas, coronary arteries and aortic branch arteries of free-living
elephants (Loxodonta africana) in Uganda and Kenya. The lesions took the
form of calcified fibrotic plaques in the inner tunica media. The
calcification appeared to commence in the internal elastic lamina and
was associated with atrophy of medial smooth muscle fibres and their
replacement by fibrous tissue. In the aorta, medial sclerosis was found
to be associated with aortic dilatation, decreased wall thickness and
decreased extensibility. These changes were shown to result in
substantial increases in the tangential stresses carried by the tissues
of the aorta and coronary arteries. As with atherosclerosis, medial
sclerosis increased progressively with age; and the approximate
involvement of the aorta at different ages could be predicted from
linear regression equations. There was no difference in the severity of
lesions between male and female animals. Biochemically, the lesions of
medial sclerosis were associated with decreased amounts of elastin and
increased amounts of collagen in arterial walls. Arterial tissue showing
medial calcification always contained less than 30% elastin by weight.
In addition, the severity of medial sclerosis in individual elephants
was found to be positively correlated with the concentration of calcium
in their sera. The pathogenesis of these lesions is discussed and it is
suggested that mechanical stress, medial anoxia and high serum calcium
levels all contribute to the aetiology of medial sclerosis.
Super, S.J.,
1975. Optometric examination of the African elephant, Loxodonta
africana africana, in south west Africa. Madogua 9, 45-51.
Abstract: Twenty-one immobilized elephants, optometrically examined in
the Etosha National Park, exhibited very little refractive error.
"Super Retinoscopy," applying sunlight for external illumination, was
used for the first time as a refractive technique. Etorphine
hydrochloride (M 99), the immobilizing agent instilled, caused
non-reacting miotic pupils. Gross anatomical observations were made on
immobilized elephant's eyes as well as on enucleated eyes.
Vogel, J.J., Ennever, J., 1975.
Lipid-dependent calcification of elephant tusk matrix. J Dent Res 54,
416.
Walker, E.P.,
1975. Order Proboscidea. Mammals of the World. John Hopkins University
Press, Baltimore, pp. 1319-1324.
Cmelik, S.,
Ley, H., 1974. Fatty acid composition of some cellular and subcellular
elements of the elephant adrenal gland. Hoppe-Seyler's Z. Physiol. Chem.
355, 797-802.
Abstract: Lipids from the cortex and medulla of the elephant adrenal
gland were extracted with chloroform/methanol, and purified over
Sephadex G-25. The total lipids, excluding gangliosides were
fractionated by a combination of Unisil columns and preparative silica
gel G plates and various fractions analyzed by gas-liquid chromatography
for their fatty acid components. Results show that nearly 70% of the
total lipids in both parts of the gland consist of cholesterol esters
differing in the content of polyunsaturated fatty acids. Phospholipids
from the cortex and medulla show an identical fatty acid pattern and are
characterized by a considerable amount of arachidonic acid.
Mitochondrial and microsomal lipids of the whole adrenal gland were
extracted, purified and fractionated in the same way. 35% of the
mitochondrial lipids consisted of cholesterol esters with C18:1, C16:0
and C20:3(omega 6) as predominant fatty acids. Triglycerides did not
contain any higher polyunsaturated fatty acids. In the phospholipids
the predominant fatty acids were C18:0, C18:1, C20:4(omega 6) and
C16:0. Microsomal lipids yielded 13% cholesterol esters with very few
polyunsaturated fatty acids and a considerable amount of C12 and C14
acids. Unlike the mitochondria, microsomes did not contain any
triglycerides. Phospholipids of the microsomes were rich in arachidonic
acid and contained polyunsaturated acids not present in other
fractions. The presence of larger quantities of C16:1 and C16:2 acids
in the adrenal gland suggests the possible existence of the omega 7
pathway, although no other metabolites were identified. The fatty acid
pattern excludes the possibility of an essential fatty acid deficiency.
Cmelik, S.,
Ley, H., 1974. Composition of the lipids from the cell sap of the
elephant adrenal cortex. Hoppe-Seyler's Z. Physiol. Chem. 355,
1463-1465.
Elder, W.H.,
Rodgers, D.H., 1974. Immobilization and marking of African elephants and
the prediction of body weight from foot circumference.
Mammalia 38, 33-53.
Jones, R.C., Skinner, J.D., Rowlands, I.W., 1974.
The role of
the urogenital ducts of the African elephant, Loxodonta africana.
Journal of Reproduction and Fertility 36, 441-442.
Perry, J.S.,
1974. Implantation, foetal membranes and early placentation of the
African elephant, Loxodonta africana. Philos. Trans. R. Soc. Lond.
[Biol] 269, 109-135.
Fawcett, D.W.,
Neaves, W.B., Flores, M.N., 1973. Comparative observations on
intertubular lymphatics and the organization of the interstitial tissue
of the mammalian testis. Biology of Reproduction 9, 500-532.
Hanks, J.,
1973. Growth and development of the ovary of the African elephant,
Loxodonata africana. Puku 7, 126-131.
Abstract: Aspects of growth and development of the ovary of the African
elephant are described. There was a pronounced hypertrophy of foetal
ovarian interstitial tissue in the second half of gestation. The left
ovary was larger than the right in the majority of prepubertal and
foetal elephants. There was a gradual increase in the mean number of
macroscopically visible follicles from the age of six years up to the
mean age of first ovulation at 14 years.
McCullagh,
K.G., 1973. Studies on elephant aortic elastic tissue. I. The
histochemistry and fine structure of the fiber. Experimental Molecular
Pathology 18, 190-201.
Abstract: Elephant arterial elastic laminae were shown to be refractory
to staining by orcein or the resorcin dyes, both normally regarded as
routine elastic tissue stains. To investigate this more thoroughly,
elastin was isolated from the arterial tissue by alkaline hydrolysis and
studied in vitro. Compared to elastin from other species,
elephant elastin was found to resist alkaline hydrolysis to a greater
extent, to possess a greater UV absorption at 275 nm, and to shown an
unusual fluorescence at 415 nm. Electron micrographs of elastic fibers
in situ demonstrated the presence of large amounts of
microbibrillar sheath surrounding the amorphous core. These results are
interpreted to indicate the presence, in elephant arterial elastic
tissue, of unusually large amounts of a nonelastin component which
interferes with the normal staining reactions.
McCullagh,
K.G., Derouette, S., Robert, L., 1973. Studies on elephant aortic
elastic tissue. II. Amino acid analysis, structural glycoproteins and
antigenicity. Experimental Molecular Pathology 18, 202-213.
Siegel, I.M.,
1973. Orthotic treatment of tibiotarsal deformity in an elephant.
Journal of the American Veterinary Medical Association 163,
544-545.
Dhindsa,
D.S., Sedgwick, C.J., Metcalfe, J., 1972. Comparative studies of the
respiratory functions of mammalian blood. VIII. Asian elephant (Elephas
maximus) and African elephant (Loxodonta africana africana).
Respiratory Physiology 14, 332-342.
Abstract: Respiratory characteristics of blood from four Asian and three
African elephants were studied. Oxygen dissociation curves of whole
blood were constructed at 37 C and corrected to a plasma pH of 7.40.
The mean blood P50 values were 25.2 ± 0.5 and 23.2 ± 1.3 mm for Asian
and African elephants, respectively, and these values are significantly
different (p< 0.01). The Bohr factors for both species were similar and
averaged -0.351 ± 0.029 log PO2/ pH. The Haldane effect was similar in
both species (5.5 vol% C CO2 at PCO2 = 40 mmHg). The concentration of
2,3-diphosphoglycerate in elephant blood is similar to that found in
normal human blood. The blood morphology of both species was similar
except that the leukocyte count was significantly higher in Asian
elephants. Starch gel electrophoresis showed that hemoglobin of Asian
elephants travels at a slower rate than hemoglobin of African elephants,
but both migrate faster than human A hemoglobin.
Hanks, J.,
Short, R.V., 1972. The formation and function of the corpus luteum in
the African elephant, Loxodonta africana . Journal of
Reproduction and Fertility 29, 79-89.
Abstract: The uterus and ovaries of 617 elephants shot in Zambia were
examined. Corpora lutea seem to be necessary for the development of
endometrial glands, and before conception can occur, a certain critical
mass of luteal tissue has to be achieved by accumulating crops of CL
from successive cycles. The elephant can be either monovular or
polyovular, and ovulation is spontaneous. New ovulations do not occur
during pregnancy, and the presence of an embryo prolongs the life of the
CL. There is great variability in luteal size, small CL being commonest
in non-pregnant animals and large ones in pregnant animals. The CL do
not enlarge during gestation, and some of the smaller ones may regress.
The number of CL in pregnant elephants varied with the age of the cow,
the younger elephants having a significantly higher number. Larger CL
(>20mm in diameter) predominated in older animals. Very little
progesterone appears to be secreted by the corpora lutea, and the
hormone could not be detected in the peripheral blood during gestation.
If progesterone is necessary for pregnancy, the elephant must be
extremely sensitive to it, and may be forced to accumulate a large mass
of relatively inactive CL before sufficient hormone is available to
enable the animal to become pregnant.
Hattingh, J.,
1972. A comparative study of transepidermal water loss through the skin
of various animals. Comp Biochem Physiol A 43, 715-718.
Haug, H.,
1972. The epiphysis and the circumventricular structures of the
epithalamus in the brain of the elephant (Loxodonta africana).
Zellforsch Mikrosk Anat 129, 533-547.
Maglio, V.J.,
1972. Evolution of mastication in the Elephantidae. Evolution 26,
638-658.
McCullagh,
K.G., 1972. Arteriosclerosis in the African elephant. I. Intimal
artherosclerosis and its possible causes. Atherosclerosis 16,
307-335.
Albl, P.,
1971. Studies on assessment of physical condition in African elephants.
Biological Conservation 3, 134-140.
Abstract: Series of external measurements were taken from 240 carcasses
of African Elephants during the dry season of 1967 in Zambia, in order
to investigate fluctuations of subcutaneous fat and muscles. In
addition, the ratio of the weight of the kidneys to kidney-fat, and the
contents of fat in the bone-marrow, were determined. From these
investigations are deduced and described simple criteria for assessment
of the physical condition of African Elephants, which criteria allow
objective classification of representative population samples. Extensive
individual variations of external anatomical features complicate
assessment of the condition. Most of the investigated external physical
features are more age- than nutrition-dependent. Only the shape of the
lumbar region and the kidney-fat index give a fairly reliable indication
of the physical condition of the African elephant.
Buss, I.O., Estes, J.A., 1971.
The
functional significance of movements and position of the pinnae of the
African elephant Loxodonta africana. Journal of Mammalogy 52,
21-27.
Abstract: Observations of wild African elephants (Loxodonta africana)
in Uganda indicated that flapping and spreading the highly vascularized
ears are probably important functions for heat dissipation. Ear
flapping increased as ambient temperatures rose and decreased or ceased
during cold or rainy weather. Rate of ear flapping was inversely
related to wind velocity. Spreading the ears reduced ear flapping,
particularly when an elephant faced downwind. Stimuli that elicited
alertness, excitement or hostility caused elephants to raise their heads
and spread their ears widely and rigidly, and large elephants
occasionally flapped their ears loudly and sharply. Flapping and
spreading the ears for heat dissipation are generally not interpreted as
danger signals by other elephants.
Hanks, J. The
reproductive physiology of the African elephant, Loxodonta africana.
1971. University of Cambridge.
Ref Type: Thesis/Dissertation
Lange, W.,
1971. Comparative studies on the cerebellum of man, the elephant and
certain toothed whales. Verhandlungen der Anatomischen Gesellschaft 65,
137-138.
Montagna, W.,
1971. Cutaneous comparative biology. Archives of Dermatology 104,
577-591.
Abstract: This article reports the biological properties and adaptive
patterns of structure and function of mammalian skin. There is an
inverse relation between the richness of pelage and the thickness and
complexity of epidermal undersurface of the epidermis. Active
melanocytes are numerous in the viscera and must have other functions
than making melanin. The dermis follows a stereotypical structural
pattern, but shows many species differences; no animal has the amounts
of elastic tissue, vascularity, and nerves as does the human. Hair
follicles differ in different species and in various parts of the body,
and are parts of the cutaneous sensory system. Sebaceous and apocrine
glands secrete pheromones. Except for horses, only man sweats in
response to heat stimulation. Thermal sweating, therefore, can be
studied only in man.
Pavelka, R.,
1971. The peripheral conduction systems in the hindlimb of Elephas
maximus. Anatomischer Anzeiger 128, 150-169.
Sikes, S.K.,
1971. The Natural History of the African Elephant. American Elsevier
Publishing Company, Inc., New York.
Singh, B.S.,
1971. Umbilical hernia in an elephant calf. Indian Veterinary Journal 48,
533-536.
Dellenback,
R.J., Chien, S., 1970. The extinction coefficient of fibrinogen from
man, dog, elephant, sheep and goat at 280 micrometers. Procedings of the
Society for Experimental Biology and Medicine 134, 353-355.
Estes, J.A.
Observations on the temporal gland of the African elephant. 1970.
Washington, USA, Washington State University.
Ref Type: Thesis/Dissertation
Haug, H.,
1970. The macroscopic structure of the cerebrum. Qualitative and
quantitative studies on the brain of humans, dolphins, and the elephant.
Ergebnisse der Anatomie und Entwicklungsgeschichte 43, 3-70.
Haug, H.,
1970. Comparative studies of the brains of men, elephants and toothed
whales. Verhandlungen der Anatomischen Gesellschaft 64 , 191-195.
Spearman,
R.I.C., 1970. The epidermis and its keratinization in the African
elephant (Loxodonta africana). Zoologica Africana 5,
327-338.
Elias, H.,
Haug, H., Lange, W., Schlenska, G., Schwartz, D., 1969. Surface area
determination of the cerebral cortex of mammals with special reference
to humans, Cetacea, elephants and Marsupialia]. Verh Anat Ges 63,
461-462.
Friant, M.,
1969. Brain development and morphology in a proboscidian, the African
elephant (Loxodonta africana Blum.). Acta Neurol Psychiatr Belg 69,
20-32.
Haug, H.,
1969. On myelinated nerve fibers and myelinated Herring bodies in the
neurohypophysis of the elephant. Z Zellforsch Mikrosk Anat 96,
134-141.
Haug, H.,
1969. Comparative quantitative studies on brains of man, elephants and
some tooth whales. I. Size of the brain cortex. Med Monatsschr 23,
201-205.
Krumrey, W.A.,
Buss, I.O., 1969. Observations on the adrenal gland of the African
elephant. Journal of Mammalogy 50, 90-101.
Abstract: Forty-nine female and 32 male African elephants (Loxodonta
africana) were collected from July 19558 to May 1959 in Bunyoro
District, Uganda. Reproductive status, body weight, and measurements
were recorded and ages estimated. Gross morphology and histology of the
adrenal gland are described: histology of the elephant adrenal
corresponds with generalized descriptions for those of other eutherian
mammals. The fetal cortex is well developed in an elephant 2 months of
age, but gradually degenerates and is completely absorbed by the fourth
year of postnatal life without giving rise to another transitory zone.
No significant increase in relative adrenal weight related to Uganda's
December-to-March dry season was detected. Relative adrenal weight of
elephants is higher in females than males of comparable age, in immature
males that mature males, and in immature females than nonpregnant or
nonlactating females. Pronounced increase in relative adrenal weight is
related to pregnancy and lactation.
Poczopko, P.,
1969. Self-defense against hyperthermia in animals. Acta Physiologica
Polonica 20, 893-905.
Duncan, W.R.,
Garton, G.A., 1968. The fatty acid composition and intramolecular
structure of triglycerides from adipose tissue of the hippopotamus and
the African elephant. Comp Biochem Physiol 25, 319-325.
Buss, I.O.,
Johnson, O.W., 1967. Relationships of Leydig cell characteristics and
intratesticular testosterone levels to sexual activity in the African
elephant. Anatomical Record 157, 191-196.
Abstract: Histological characteristics of testis tissues from 25 African
elephants (Loxodonta africana) collected in Uganda, showed no consistent
relationships among the following variables: Leydig cell size,
cytoplasmic characteristics, and abundance; testicular testosterone
content; and age. From these findings, plus field observations of
sexual behavior, emerges the hypothesis that individual cyclicity in
Leydig cell function was inherent in the elephant population studied.
Testosterone content of testes from 32 elephants (including the 25
studied histologically) suggested that lone bulls were not of a senile
nature since they contained relatively large quantities of testosterone
and were relatively young (from about 12 to 25 years of age). Also,
lone bulls were observed searching out estrous females. Among bulls
collected from family units and herds, testosterone levels and behavior
differed conspicuously. Behavior appeared to be directly related to
testosterone content in several instances. Non-aggressive behavior
among members of bull herds, plus the high proportion of such
individuals with low testosterone content, suggest that some of these
animals were in a depressed phase of sexual activity whereas others were
undergoing pubertal development.
Johnson, O.W.,
Buss, I.O., 1967. The testis of the African elephant (Loxodonta
africana). II. Development, puberty and weight. Journal of
Reproduction and Fertility 13, 23-30.
Johnson, O.W.,
Buss, I.O., 1967. The testis of the African elephant (Loxodonta
africana). I. Histological features. Journal of Reproduction and
Fertility 13, 11-21.
Koikegami,
H., Ozaki, N., 1967. Studies on the paralimbic brain structures. 3. On
the nucleus accumbens and on the olfacto-tegmental tract in the Indian
elephant. Acta Med Biol (Niigata) 15, 131-140.
Kubota, K.,
1967. Comparative anatomical and neurohistological observations on the
tongues of elephants (Elephas indicus and Loxodonta africana).
Anatomical Record 157, 505-515.
Abstract: Frozen sections from Indian and African elephant tongues were
investigated neurohistologically. On the dorsum there are 3 to 5
vallate papillae. Foliate papillae consisting of 18 to 27 clefts are
observed in the posterolateral region of the tongue. Wart-like papillae
are distributed along the lateral border of the tongue from the foliate
papillae region to the apex. Vallate and foliate papillae contain
serous glands but have no taste buds. They are supplied with abundant
lamellated corpuscles of Pacinian type in their upper mucosa. The
wart-like papillae are composed of two or more papillae, each of which
has many secondary papillae supplied with plexiform thin and thick
nerves. They bear a few taste buds and contain lamellated corpuscles of
Pacinian type. From these neurohistologic characteristics wart-like
papillae should be regarded as a receptive organ for secretion of the
lingual glands. Lamellated corpuscles of Pacinian type are widely
distributed over the whole surface of the tongue. The histologic
location of these two structures is of interest in suggesting than they
together play important roles as receptors of taste and tactile
sensations during mastication of food. Double motor end plates are
fround on single muscle fibers. The mixed glands which are plentiful in
the inferolateral area of the tongue are in close topographic relation
with the wart-like papillae.
Kunzel, E.,
Luckhaus, G., 1967. Comparative anatomical studies of the soft palate of
mammals: the palatal cartilage and the "M. uvulae" of the India elephant
(Elephas maximus). Anatomischer Anzeiger 120, 318-322.
Laws, R.M.,
Parker, I.S.C., Archer, A.L., 1967. Estimating live weights of elephants
from hindleg weights. East African Wildlife Journal 5, 106-111.
O'Donoghue,
P.N., Sikes, S.K., Turvey, A., 1967. Notes on the adrenal of the African
elephant. Journal of Zoology (Lond) 152, 281-286.
Abstract: Sections of the adrenals of two male specimens of Loxodonta
africana were examined. Apart from the dimensions of the gland and
the amount and disposition of connective tissue in it, the most
characteristic features were the very high lipid content of the cortical
secretory cells, the large size of these cells, and the occurrence of
dark cells in the zona fasciculata.
Rooney, J.R.,
II, Sack, W.O., Habel, R.F., 1967. Guide to the dissection of the horse.
Wolfgang O. Sack, Ithaca, New York.
Short, R.V.,
Mann, T., Hay, M.F., 1967. Male reproductive organs of the African
elephant, Loxodonta africana. Journal of Reproduction and
Fertility 13, 517-536.
Young, E.,
Lombard, C.O., 1967. Physiological values of the African elephant (Loxodonta
africana). The Veterinarian 4, 169-172.
Abstract: The following physiological values of African elephants
determined in the Kruger National Park are recorded in this article: Red
cell count, hematocrit, mean corpuscular volume, mean corpuscular
hemoglobin, mean corpuscular hemoglobin concentration, total hemoglobin,
erythrocyte sedimentation rate, total white cell count, differential
white cell count, blood urea nitrogen, body temperature, and pH of the
blood plasma, saliva, urine and faeces.
Haug, H.,
1966. Cyto-architectural studies on the cerebral cortex of the elephant.
Verh Anat Ges 61, 331-337.
Horstmann,
E., 1966. The epidermis of the elephant. Z. Zellforsch. Mikrosk. Anat.
75, 146-59.
Hungerford,
D.A., Chandra, H.S., Snyder, R.L., Ulmer, F.A., 1966. Chromosomes of
three elephants, two Asian (Elephas maximus) and one African (Loxodonta
africana). Cytogenetics 5, 243-246.
Abstract: Cultured somatic cells of three elephants, male and female
Asian (Elephas maximus) and female African (Loxodonta africana),
had 56 chromosomes. Karyotypes of the Asian specimens were
morphologically identical, except for the sex chromosomes, and that of
the African specimen closely similar. Identification of the African X
was made by inference.
Kamiya, T.,
Fujita, T., 1966. The intramural pouch in the duodenum of the Indian
elephant: a macro- and microscopic study of six cases. Okajimas Folia
Anatomica Japonica 42, 281-294.
Laws, R.M.,
1966. Age criteria for the African elephant, Loxodonta a. africana.
East African Wildlife Journal 4, 1-37.
Buss, I.O.,
Wallner, A., 1965. Body temperature of the African elephant. Journal of
Mammalogy 46, 104-107.
Holm, N.E.,
1965. The musculature of the forelimbs of the Elephas indicus.
Anatomischer Anzeiger 117, 171-192.
Amoroso, E.C.,
Perry, J.S., 1964. The foetal membranes and placenta of the African
elephant. Philos. Trans. R. Soc. Lond. [Biol] 248, 1-34.
Cave, A.J.E.,
Aumonier, F.J., 1964. Lymph node structure in an Asiatic elephant.
Journal of the Royal Microscopic Society 82, 251-255.
Cooper, R.A.,
Connell, R.S., Wellings, S.R., 1964. Placenta of the Indian elephant,
Elephas indicus. Science 146, 410-412.
Abstract: The placenta of the Indian elephant is incompletely annular
and zonary microscopically and occupies the equator of an ovoid
chorioallantoic sac. The amnion is fused with the chorion over the
zone. Microscopically, the placenta is labyrinthine and
endotheliochorial with a rudimentary marginal hematoma. Both
macroscopically and microscopically it resembles the placentas of the
carnivores, particularly the raccoon, the cat and the dog.
French, J.E.,
1964. Atherosclerosis. In: Florey, H. (Ed.), General pathology. Loyd-Luke,
London, pp. 418-446.
Jayasinghe,
J.B., Fernando, S.D.A., Brito-Babapulle, L.A.P., 1964. The
electrocardiogram of a baby elephant. American Heart Journal 67 ,
388-390.
Johnson, O.W.
Histological and quantitative characteristics of the testes,
observations on the teeth and pituitary gland, and the possibility of
reproductive cyclicity in the African elephant (Loxodonta africana).
1-124. 1964. Pullman, Washington, USA, Washington State University.
Ref Type: Thesis/Dissertation
Perry, J.S.,
1964. The structure and development of the reproductive organs of the
female African elephant. Philos. Trans. R. Soc. Lond. [Biol] 248,
35-52.
Villasenor,
C., 1964. A new cellular type found in the liver of Elephas maximus.
Gaceta Medica de Mexico 94, 403-405.
Bartels, H.,
Hilpert, P., Barbey, K., Betke, K., Riegel, K., Lang, E.M., Metcalfe,
J., 1963. Respiratory functions of blood of the yak, llama, camel,
Dybowski deer and African elephant. American Journal of Physiology 205,
331-336.
Abstract: Blood samples from a yak, llama, camel, deer, and African
elephant were analyzed for oxygen capacity, "standard bicarbonate"
content, oxygen dissociation curve, and the magnitude of the Bohr and
Haldane effects. These parameters of the respiratory function of the
blood have been related to the morphology of the red cells, to the
weights of the animals, and to the important electrolytes in the
erythrocytes and in the plasma. The high affinity for oxgen described
previously for llama blood is shared by its relative, the camel. Both
of these animals have a high concentration of hemoglobin within their
erythrocytes. Blood from the African elephant showed the greatest
affinity for oxygen among the subjects studied.
Brattstrom,
B.H., Stabile, A.J., Williams, F.R., Des Lauiers, J., Pope, D., 1963.
Body temperature of Indian elephants. Journal of Mammalogy 44,
282-283.
Dougall, H.W.,
1963. On the chemical composition of elephant faeces. East African
Wildlife Journal 1, 123.
Engel, S.,
1963. The respiratory tissue of the elephant (Elephas indicus),
second communication. Acta Anatomica Nipponica 55, 105-111.
Abstract: The acini of the elephant lung are small but extremely
numerous, thus providing an extensive respiratory surface. The
parenchyma is subdivided by elastic strands encapsulating small areas of
parenchyma. Many, especially peripheral, acini have a lymph system of
their own, conspicuously marked by round, peduncular lymph nodes.
Generally speaking, the Elephant lung is built up according to the usual
pattern of the mammalian lung but contains peculiar structures necessary
for the bulk of the body and the volume of the lung.
Fernando,
S.D.A., Jayasinghe, J.B., Panabokke, R.G., 1963. A study of the temporal
gland in an Asiatic elephant (Elephas maximus). Ceylon Veterinary
Journal 11, 108-111.
Jayasinghe,
J.B., Fernando, S.D.A., Brito-Babapulle, L.A.P., 1963. The
electrocardiographic patterns of Elephas maximus -- the elephant
of Ceylon. British Veterinary Journal 119, 559-564.
Riggs, A.,
1963. The amino acid composition of some mammalian hemoglobins: mouse,
guinea pig and elephant. Journal of Biological Chemistry 238,
2983-2987.
Cave, A.J.E.,
Aumonier, F.J., 1962. Elephant and rhinoceros lymph node histology.
Journal of the Royal Microscopic Society 80, 209-214.
Abstract: The histology is described, for the first time, of certain
lymph nodes of the African Elephant (Loxodonta africana
Blumenbach), of the Great Indian Rhinoceros (Rhinoceros unicornis
Linn.) and of the African Black Rhinoceros (Diceros bicornis
Linn.): reference is made to the nodes of the African White Rhinoceros (Ceratotherium
simum Gray). All nodes studied prove to be haemolymph organs.
Evans, G.H.,
1961. Elephants and Their Diseases: A Treatise on Elephants. Government
Printing, Rangoon, Burma.
Gill, J.,
1960. Rate of passage through the digestive tract of Indian elephants (Elephas
maximus) under zoo conditions. Acta Physiologica Polonica 11,
272-289.
Kohira, E.,
1960. The spleen of the Elephas indicus. Acta Anatomica Nipponica
35, 253-260.
Shimizu, Y.,
Fujita, T., Kamiya, T., 1960. Anatomy of a female Indian elephant with
special reference to its visceral organs. Acta Anatomica Nipponica 35,
261-301.
Hashimoto,
Y., Yamauchi, S., Yasunobo, E., 1956. Dissection of an elephant.
Bulletin University Osaka Prefecture series B 6, 30-52.
Shindo, T.,
Mori, M., 1956. Musculature of the Indian elephant. Part III.
Musculature of the trunk, neck, and head. Okajimas Folia Anat. Japonica
29, 17-40.
Shindo, T.,
Mori, M., 1956. Musculature of the Indian elephant. Part II.
Musculature of the hindlimb. Okajimas Folia Anat. Japonica 28,
114-147.
Shindo, T.,
Mori, M., 1956. Musculature of the Indian elephant. Part I.
Musculature of the forelimb. Okajimas Folia Anat. Japonica 28,
89-113.
Friant, M.,
1954. [Form of the brain of elephant (Loxodonta africana Blum.) during
prenatal life.]
2306. C. R. Hebd. Seances Acad. Sci. 238, 1534-1535.
Hanstrom, B.,
1953. The hypophysis in some South African insectivora, carnivora,
hyracoidae, proboscidea, artiodactyla and primates. Arkiv foer Zoologi
(Stockholm) 4, 187-294.
Hill, W.C.O.,
1953. The anatomy of the African elephant. In: Ward, R. (Ed.), The
Elephant in East Central Africa. Rowland Ward, Ltd., London and Nairobi,
pp. 15-60.
Perry, J.S.,
1953. The reproduction of the African Elephant, Loxodonta africana.
Philos. Trans. R. Soc. Lond. [Biol] 237, 93-149.
Ayer, A.A.,
Mariappa, D., 1952. A radiographic study of ossification in the Indian
elephant fetus. Journal of the Anatomical Society of India 1,
3-10.
Engel, S.,
1952. The respiratory tissue of the elephant (Elephas indicus).
Acta Anatomica Nipponica 16 , 308-314.
Friant, M.,
1951. [The form of the brain, during ontogeny, in elephants (Elephantidae).].
C. R. Hebd. Seances Acad. Sci. 232, 2137-2138.
Garutt, V.E.,
1951. [Modification of the structure of carpal bones of Proboscidea in
relation to conditions of environment.]. Dokl. Akad. Nauk SSSR 77,
513-515.
WEGNER, R.N.,
1951. [The processes cucularis mandibulae in the Elephantidae, Serenia,
Rhinocerotidae and Suidae.]. Anatomischer Anzeiger 98, 66-82.
Ayer, A.A.,
Mariappa, D., 1950. External characters of three fetuses of the Indian
elephant. Proceedings of the Indian Academy of Science XXXI(B),
193-209.
Bourne, G.H.,
1949. The mammalian adrenal gland. Oxford at the Clarendon Press,
Oxford.
Weatherford,
H.L., 1940. Some observations on the tusks of an Indian elephant. The
innervation of the pulp. Anatomical Record 76, 81-93.
Wislocki, G.B.,
1940. The topography of the hypophysis of the elephant, manatee, and
hyrax. Anatomical Record 77, 427-445.
Wislocki, G.B.,
1939. Note on the hypophysis of an adult Indian elephant. Anatomical
Record 74, 321-328.
Benedict, F.G.,
Lee, R.C., 1938. Further observations on the physiology of the elephant.
Journal of Mammalogy 19, 175-194.
Hill, W.C.O.,
1938. The external and radiological anatomy of a foetal Asiatic
elephant. Ceylon Journal of Science 21, 31-43.
Hill, W.C.O.,
1938. Studies on the cardiac anatomy of the elephant: II -- the heart
and great vessels of a foetal Asiatic elephant. Journal of Science 21,
44-61.
King, R.L.,
Burwell, C.S., White, P.D., 1938. Some notes on the anatomy of the
elephant's heart. American Heart Journal 16, 734-743.
Neuville, H.,
1937. Recherches comparatives sur l'organe femelle des elephants avec
remarques sur les formations dites hymenales. Annales des Scinces
Naturelles,Zoologies et Biologie Animale 20 10, 245-295.
Schulte, T.L.,
1937. The genito-urinary system of the Elephas indicus male.
American Journal of Anatomy 61 , 131-157.
Benedict, F.G.,
1936. The physiology of the elephant. Carnegie Institution of
Washington, Washington.
Benedict, F.G.,
Lee, R.C., 1936. Studies on the body temperatures of elephants. Proc
Natl Acad Sci U S A 22, 405-408.
Friant, M.,
1933. La regression de la levre superieure au cours de l'otogenie
individual chez l'elephant. C. R. Acad. Sci. Paris 878-879.
Boyle, D.,
1929. Height in elephants. Journal of the Bombay Natural History Society
33, 437.
Eales, N.,
1929. The anatomy of a foetal African elephant, Elephas africanas
(Loxodonta africana). Part III. The contents of the thorax and
abdomen, and the skeleton. Transactions of the Royal Society of
Edinburgh 56, part I, 203-246.
Eales, N.,
1928. The anatomy of a foetal African elephant, Elephas africanas
(Loxodonta africana) Part II. The body muscles. Transactions of
the Royal Society of Edinburgh 55, part III, 609-642.
Eales, N.,
1926. The anatomy of the head of a foetal African elephant, Elephas
africanas (Loxodonta africana). Transactions of the Royal
Society of Edinburgh 54, part III, 491-551.
Eales, N.B.,
1925. External characteristics, skin, and temporal gland of a foetal
African elephant. Procedings of the Zoological Society of London 2,
445-456.
Petit, G.,
1924. Sur l'abouchement des canaux deferents et de vesicules seminales
au verumontanum de l'elephant. Bull. Mus. Hist. Nat. , Paris 30,
441.
Benedict, F.G.,
Fox, E.L., Baker, M.L., 1921. The skin temperature of pachyderms.
Proceedings of the National Academy of Sciences of the United States of
America 7, 154-156.
Putter, A.,
1918. Studien uber physiologische Xhnlichkeit. Arch. f. d. ges. Physiol.
172, 367-412.
Bolk, L.,
1917. Anatomical notes on a fetus of Elephas africanus. J. Muller,
Amsterdam.
Todd, T.W.,
1913. Notes on the respiratory system of the elephant. Anatomischer
Anzeiger 44, 175-183.
Evans, G.H.,
1910. Elephants and Their Diseases: A Treatise on Elephants. Government
Printing, Rangoon, Burma.
Assheton, R.,
Stevens, T.G., 1905. Notes on the structure and the development of the
elephant's placenta. Quarterly Journal of Microscopical Science 49,
1-37.
Paterson,
A.M., 1898. The genito-urinary organs of the female Indian elephant.
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