Cervus unicolor niger
1) General Zoological Data
In most classifications, Sambar deer belong to the subgenus Rusa. Both are Hindi names for deer. Sambars are widely distributed through India, South-East Asia and many Pacific Islands and have been introduced to Australia and New Zealand (Wilson & Reeder, 1992). Some of the islands may also have sambars that were recently introduced. The subgenus (Rusa) has four species (C. alfredi, C. marianus, C. unicolor, C. timorensis). The German designation often used is "Aristotlehirsch", since the animal was already well-known to Aristotle from West India. It was then also designated as being characteristically a six-pointer. In German, these animals are also referred to as "Pferdehirsch" because of their long legs. A recent study of mtDNA by Randi et al. (2001) suggests that this clade separated from other cervidae around 5 MYA. Nowak (1999) referred to recent electrophoretic findings that have suggested a close relationship to Axis and Dama deer. Haltenorth (1968) differentiated three species, with 18 subspecies. Adult males are larger than females and have characteristically 6 antler points and long legs. Their weights vary from 100-315 kg. Sambars are reported to be more of a browsing than grazing animal that prefers to live in wooded regions. Newborns weigh around 10 kg. The longevity in captivity is at least 24 years and 5 months (Jones, 1993).
Because of the availability of this specimen and the large size of its placental cotyledons, this deer species is treated here separately; other cervid species are detailed in a separate chapter, on "Deer species" (see there for more discussion).
General Gestational Data
The length of gestation is 8 months or 240 days (Nowak, 1999; Hayssen al., 1993) with usually single offspring. Records of twins exist, but they occur uncommonly (Hayssen et al., 1993). Plotka (1999) referred to studies that indicate that the length of gestation is 240-270 days.
General Characterization of the Placenta
As other deer species, sambars have only a small number of caruncles and, therefore, cotyledons. This specimen had six cotyledons that were of rather large size. This is thus an "oligo-cotyledonary", epithelio-chorial placenta without invasion into the maternal tissue, much like that of most other cervidae studied (see Hamilton et al., 1960). The cotyledons have a convex shape.
Details of fetal/maternal barrier
The microscopic details of the cotyledonary and arcade structures of the sambar deer placenta are most similar to the other deer species studied. They have been summarized in detail in publications by Sinha et al. (1969) and by Hamilton et al. (1960). Most of this is reviewed in some detail in the other general chapter on "Deer Species" to which the reader is referred. This placenta is mostly remarkable because of the large size of the cotyledons. They are so large that a complete cross section cannot be fitted onto one slide. Binucleate trophoblast are present as in other ruminants; they PAS-positive and one has to assume that they also produce relaxin or lactogen as other ungulates, although that has not been shown for this species. The fetal capillaries course within the trophoblastic cover of the villi.
The umbilical cord of this pregnancy measured 7 cm in length, had four blood vessels and a large, patent allantoic duct. The cord was not spiraled. The surface of the umbilical cord had large stretches of massive squamous metaplasia, as shown below. The amnionic epithelium had fine granules on its surface, also consisting of squamous metaplasia. The allantoic duct shown below was lined by urothelium and was empty. It was accompanied by a large number of small blood vessels.
I know of no studies in this deer species.
Cooper, D.W. and Herbert, C.A.: Genetics, biotechnology and population management of over-abundant mammalian wildlife in Australasia. Reprod. Fertil. Dev. 13:451-458, 2001.
Dratch, P.A. and Pemberton, J.M.: Application of biochemical genetics to deer management: What the gels tell. Chapter 87, pp.367-389, in: The Biology of Deer, R.D. Brown, ed. Springer-Verlag, N.Y., 1991.
Gray, A.P.: Mammalian Hybrids. A Check-list with Bibliography. 2nd edition. Commonwealth Agricultural Bureaux Farnham Royal, Slough, England, 1972.
Griner, L.A.: Pathology of Zoo Animals. Zoological Society of San Diego, San Diego, California, 1983.
Groves, C.P. and Grubb, P.: Relationships of living deer. Pp. 21-59, in Biology and Management of the Cervidae. C.M. Wemmer, ed. Smithsonian Institution Press, Washington, D.C. 1987.
Halnan, C.R.E., ed.: Cytogenetics of Animals. CAB International, Oxford, 1989.
Haltenorth, Th.: Hirsche. Chapter 8 (pp. 168-272) in, Grzimeks Tierleben, Volume 13. Kindler Verlag, Zürich, 1963.
Hamilton, W.J., Harrison, R.J. and Young, B.A.: Aspects of placentation in certain cervidae. J. Anat. 94:1-33, 1960.
Hayssen, V., van Tienhoven, A. and van Tienhoven, A.: Asdell's Patterns of Mammalian Reproduction: a Compendium of Species-specific Data. Comstock/Cornell University Press, Ithaca, 1993.
Heuschele, W.P., Oosterhuis, J., Anderson, M.P., Swansen, M. and Fletcher, H.R.: Malignant catarrhal fever in wild ruminants. Chapter 25 (pp. 296-308) in, One Medicine, O.A. Ryder and M.L. Byrd, eds. Springer-Verlag N.Y., 1984.
Hsu, T.C. and Benirschke, K.: An Atlas of Mammalian Chromosomes. Folio 344, Vol. 7 1973. Springer-Verlag, N.Y.
Jones, M.L.: Longevity of ungulates in captivity. Intern. Zoo Yearbk. 32:159-169, 1993.
Miyamoto, M.M., Kraus, F. and Ryder, O.: Phylogeny and evolution of antlered deer determined from mitochondrial DNA sequences. Proc. Natl. Acad. Sci. 87:6127-613, 1990.
Neitzel, H.: Chromosomenevolution in der Familie der Hirsche (Cervidae). Bongo 3:27-38, 1979
Nowak, R.M.: Walker's Mammals of the World. 6th ed. The Johns Hopkins Press, Baltimore, 1999.
Plotka, E.D.: Deer. Pp 842-857, in, Encyclopedia of Reproduction. E. Knobil and J.D. Neill, eds. Vol. 1, Academic Press, San Diego, 1999.
Randi, E., Mucci, N., Claro-Hergueta, F., Bonnet, A. and Douzery, J.P.: A mitochondrial DNA control region phylogeny of the Cervinae: speciation in Cervus and implications for conservation. Anim. Conser. 4:1-11, 2001.
Sinha, A.A., Seal, U.S., Erickson, A.W. and Mossman, H..: Morphogenesis of the fetal membranes of the white-tailed deer. Amer. J. Anat. 126:201-241, 16.
Sinha, A.A., Seal, U.S. and Erickson, A.W.: Ultrastructure of the amnion and amniotic plaques of white-tailed deer. Amer. J. Anat. 127:369-396, 1970.
Wang, Z. and Du, R.: Evolution of karyotype of the genus Cervus. Acta Genet. Sinica 9:24-31, 1982 (in Chinese).
Wilson D.E. and Reeder, Eds.: Mammal Species of the World. Second Ed. Smithsonian Institution Press, Washington, DC, 1992.
Wooding, F.B., Morgan, G. and Adam, C.L.: Structure and function in the ruminant synepitheliochorial placenta: central role of the trophoblast binucleate cell in deer. Microsc. Res. Tech. 38:88-99, 1997.
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