1) General zoological data of species
Wetzel and Crespo (1975) formally first described this third species of peccary. It is restricted to the Chaco region of Paraguay, Northern Argentina and Eastern Bolivia (Taber, 1993). Contrary to the other two species of peccary (collared peccary and white-lipped peccary), this animal forms small family groups of up to eleven individuals. It has become very rare in the "Chaco Boreal" and was feared of becoming extinct. It was thus declared a "CITES I" species and hunting bans were introduced. It has become my favorite animal. With the Zoological Society of San Diego I formed a breeding colony of these animals near the center of the Paraguayan Chaco, in Toledo. Hundreds of animals were bred, released, and some were exported to Phoenix, Arizona, USA. Offspring of that colony went to the San Diego Zoo, and offspring bred there went to zoos in St. Louis and Los Angeles. The species is now sparsely distributed in the same habitat, which is, however, shrinking because of an expanding agriculture (Handen et al., 1994). Oversight is now accomplished by the Pigs and Peccaries" group of IUCN (Oliver, 1993) and a SSP by AZA.
Adult female taguá weigh around 35 kg. They have longer legs and a much larger head than the collared peccary with which the animal is otherwise similar. Detailed anatomical descriptions have been published by Olrog et al. (1976) and by Wetzel (1977), the original discoverer of this species.
|Family Group of taguá at Toledo, Paraguay.|
2) General gestational data
A pregnant female was reported to have weighed 43.5 kg (Mayer & Wetzel, 1986). Litters vary from 2-4 (average 2.72, triplets being most common). Neonates weigh around 400-600 g. The length of gestation has been given as 184 days (Brooks, 1992) but it may be shorter, as it is in the other two peccary species. The mesonephroi of fetuses are unusually large, and fetal as well as adult ovaries contain a huge central "interstitial gland" whose products are unknown. The placental weight has not yet been determined.
|Parents and two young at San Diego Zoo, 1999.|
diffuse epithelio-chorial placenta occupies the uterus diffusely. It has
"ripples" on its surface and possesses a large allantoic sac,
a relatively short umbilical cord, and a small amnionic cavity. There
is no trophoblastic invasion of the uterus. The placenta is similar to
those of Suidae and other Tayassuidae (Macdonald & Bosma, 1985). Most
recently, Miglino et al. (2001) have studied the placentas of the other
two species of peccaries. They used very fresh material that was collected
under optimal condition. Santos et al. (2006) have published excellent details of the placentas in 13 collared peccaries and 3 white-lipped peccaries, in addition to superior electronmicroscopic studies. As in taguá, their placentas are diffuse, epitheliochorial organs without trophoblastic invasion.
|Delivered term taguá placenta, diffuse and very thin.|
4) General characteristic of placenta
The peccary has a diffuse epithelio-chorial placenta with large allantoic sac, which has a lining of columnar epithelium. In a specimen of triplets, I found the fetuses occupied both uterine horns; the placentation was trichorionic and there were three corpora lutea present in the maternal ovary. The allantoic sac has abundant fine blood vessels.
|First trimester triplet in its placenta whose external surface is rippled by the villi.|
|Delivered term placental histology. Amnion at left and is attached to the chorion. Villi at right.|
5) Details of barrier structure
The cuboidal chorionic epithelium directly apposes the endometrial epithelium and beneath which there is a large capillary network. PAS-positive secretion is present in the endometrial glands, but not within the epithelial cells. In the trophoblast are subnuclear PAS-positive vacuoles, similar to what has been described of Suidae (Macdonald & Bosma, 1985). There is no true syncytium.
|First trimester taguá implantation. The uterus is left, placenta right.|
|Taguá placenta of stillbirth, vacuolated trophoblast.|
|Higher magnification of villous surface.|
|Trophoblast with PAS+ vacuoles.|
Trophoblast external to barrier
|Two ovaries of an adult, nonpregnant female. The central "interstitial gland" is labeled I, the thin cortex contains the ova.|
|Microscopic appearance of ovarian cortex (left) and interstitial gland (right).|
Gongora & Moran (2005) have further examined nuclear and mitochondrial genes of all three species. They found greater mitochondrial gene divergence in collared peccaries than among the other two species, which are more closely related to each other than to collared peccaries. In addition, these authors reconsidered the question as to whether divergence originated before or after invasion of peccaries into South America after the landbridge was established. But final resolution of this question still awaits additional specimen study.
Benirschke, K., Byrd, M. and Meritt, D.: New observations on the Chacoan peccary, Catagonus wagneri. Pp. 341-347, In. 32nd International Symposium on Erkrankungen der Zootiere (Eskilstuna, 1990). Akademie-Verlag, Berlin.
Benirschke, K., Gonzalez, S., Gould, G., Byrd, M. and Kumamoto, A.: Observations on the Chacoan peccary (Catagonus wagneri). Pp. 391-397, In, 28th International Symposium on Erkrankungen der Zootiere (Rostock, 1986). Akademie-Verlag, Berlin.
K., Hager, D.A. and Edwards, D.K.: Observations on neonatal mortality
of the Chacoan peccary Catagonus wagneri. Vet. Path. 37:532-534,
Benirschke, K. and Kumamoto, A.T.: Further studies on the chromosomes of three species of peccary. Adv. Neotrop. Mammal. 309-316, 1989.
Benirschke, K., Low, R.J. and Byrd, M.: Further observations on the causes of death in the Chacoan peccary, Catagonus wagneri. Pp. 71-78, In 31st International Symposium on Erkrankungen der Zootiere (Dortmund, 1989). Akademie-Verlag, Berlin.
Brooks, D.M.: Reproductive behaviour and development of the young of the chacoan peccary (Catagonus wagneri, Rusconi, 1930) in the Paraguayan Chaco. Z. Säugetierk. 57:316-317, 1992.
Bosma, A.A., de Haan, N.A., Arkesteijn, G.J.A., Yang, F., Yerle, M. and Zijlstra, C.: Comparative chromosome painting between the domestic pig (Sus scrofa) and two species of peccary, the collared peccary (Tayassu tajacu) and the white-lipped peccary (T. pecari): a phylogenetic perspective. Cytogenet. Genome Res. 195:115-121, 2004.
Byrd, M.L., Benirschke, K. and Gould, G..C.: Establishment of the first captive group of the Chaco peccary, Catagonus wagneri. Zool. Garten 5/6:265-274, 1988.
Cell strains from: www.sandiegozoo.org (CRES section).
Gongora, J. and Moran, C.: Nuclear and mitochondrial evolutionary analyses of Collared, White-lipped, and Chacoan peccaries (Tayassuidae). Molec. Phylogenet. Evol. 34:181-189, 2005.
Handen, C.E., Unger, J. and Meritt, D.: Current status of the taguá (Catagonus wagneri) in Paraguay. Zool. Garten 64:329-337, 1994.
Macdonald, A.A. and Bosma, A.A.: Notes on placentation in the Suina. Placenta 6:83-92, 1985.
Marshall, L.G.: Land Mammals and the Great American Interchange. Amer. Scientist 76:380-386, 1988.
J.J. and Brandt, P.N.: Identity, distribution, and natural history of
the peccaries, Tayassuidae. In, Mammalian Biology in South America (M.A.
Mares & H.H. Genoways, eds.) Special Publication Series Pymatuning
Lab. Ecol., University of Pittsburgh, pp. 433-454, 1982.
Miglino, M.A., Santos, T.C. and Dantzer, V.: The collared peccary (Tayassu tajacu Linnaeus, 1795) and white-lipped peccary (Tayassu pecari Link, 1795) placenta. Abstract 80 in, Placenta 22(7):A28, p80, 2001.
Oliver, W.L.R.: Pigs, Peccaries, and Hippos. IUCN, Gland, Switzerland, 1993.
Olrog, C.C., Ojeda, R.A. and Barquez, R.M.: Catagonus wagneri (Rusconi) en el Noreste Argentino. Neotropica 22:53-56, 1976.
Santos, T.C., Dantzer, V., Jones, C.J.P., Oliveira, M.F. and Miglino, M.A.: Macroscopic and microscopic aspects of collared peccary and white-lipped peccary placenta. Placenta. 27:244-257, 2006.
Sowls, L.K.: The Peccaries. (Chapter 10, the Chacoan Peccary). Univ. Arizona Press, Tucson, AZ, 985.
Taber, A.: Monographie des Chaco-Pekaris (Catagonus wagneri). Bongo 18:135-150, 1990.
Theimer, T.C. and Keim, P.: Phylogenetic relationships of peccaries based on mitochondrial cytochrome B DNA sequences. J. Mammal. 79:566-572, 1998.
Wetzel, R.M. and Crespo, J.A.: Existencia de una tercera especie de pecari, Fam. "Tayassuidae, Mammalia", en Argentina. Rev. Museo Argentino de Sciencias Naturales 12:25-26, 1975.
Wetzel, R.M., Dubos, R.E., Martin, R.L. and Myers, P.: Catagonus, an "extinct" peccary, alive in Paraguay. Science 189:379-381, 1975.
Wetzel, R.M.: The Chacoan Peccary Catagonus wagneri (Rusconi). Bull. Carnegie Museum Natural History, Pittsburgh, # 3, 1-36, 1977.
Yahnke, C.J., Unger, J., Lohr, B., Meritt, D.A. and Heuschele, W.: Age specific fecundity, litter size, and sex ratio in the Chacoan peccary (Catagonus wagneri). Zoo Biol. 16:301-307, 1997.
|The neonatal uterus and appendages are shown here because of the rarity of the specimen. Note the very long vagina.|
© 2007. All rights reserved. welcome | home | index | intro | placentation | glossary | author | contact