N. Marsono, M. Utami, W.E. Setiowati, T.S. Puntorini,

D.P. Astuti, N. Andayani & Vega

Abstract

The Ragunan Zoo has been concentrating for several years on identifying the karyotypes of mountain anoa and low land anoa. Genetic management of zoo animals must encompass all captive animal species. Chromosome analysis has become an essential part in the genetic management. It is very important to do this program continually to have a clear distinction between hybrids and pure-breed specimens, which is not always possible with phenotype alone, especially in young animals. With chromosomal study it is possible to prevent breeding from hybrid animals. Ragunan zoo has 8 anoas, two of them from the wild and the others from exchange program with other zoos.

The anoa, a forest dwelling dwarf buffalo, is one of several interesting animal endemic to Sulawesi. There are two distinct species: a highland or mountain (Anoa quarlesi) and lowland anoas (Anoa depressocornis). These two species can be distinguished from each other by some morphological differences (Groves 1969 and Malih 1972). Low land anoas (1.7- 1.9 m) are bigger than mountain anoas (1.2-1.5m) in size. There are also differences in their fur color and texture, tail length, and the shape of their horns.

The anoa is protected by Indonesian law, and in the Red Data Book (1971) it is categorized as endangered. Both species of anoa are listed as endangered in the 1994 IUCN Red List (Groombridge,1993) and both are included in Cites Appendix. One of the resolution of the seminar on wildlife held in 1983 at the Animal Research Centre in Bogor" was that wildlife conservation should be done both in situ and ex situ.

The basic problem linking genetics to conservation is that small population whether in the wild or in captivity, tend to lose genetic variation over time. This loss of variation may well increase the probability of population extinction or reduce opportunities for future adaptation through evolutionary change.

Anoa is a shy animal and prefers to stay hidden. Nevertheless, they can be aggressive (Kondo 1972) and can attack their enemies by using their horns (Gzimek 1972). Their distribution in Indonesia on the Sulawesi island, from north to south.

Currently, in the zoo there are two male and two female adult mountain anoas, and one male and one female adult lowland anoa. A captive bred female calf is difficult to identified. Phenotypically she is very similar to her parents. There is also a wild caught male calf from central Sulawesi.

Eight anoas from wild caught population were used: two anoas from central Sulawesi and six anoas from the Zoo population. External morphology, hair and color pattern and horn form were observed. Mitotic chromosome preparations were prepared from whole blood cultures according to standard procedures. G-banding was done as described by Wong and Fedoroff (1972).

Results

Every anoa has been permanently identified by Trovan transponder placed at the base of the right ear. Newly arrived animals, either by birth or transfer will immediately be given temporary identification until permanent numbers are assigned. Animal recordsconsist of: place of origin, date of capture, date of arrival at the institution, date of birth if captive born, sire and dam (Table 1).

Table 1: Captive Anoa population in Ragunan Zoo on September

The chromosome number of Buton and Murni(whose heads resemble that of sheep) from Central Sulawesi (A. quarlesi) is 46 (2n) consisting of 7 pairs of metacentric/ submetacentric and 15 pairs of telocentric autosomes and 1 pair of acrocentric sexual chromosome (table 4).

The chromosome number of Marleni from an exchange program (Table 4), is 38 (2n) consisting of 11 pairs of metacentric / submetacentric, 7 pairs of Telocentric and 1pair acrocentric sexual chromosomes . These findings disagree with the chromosome set of 2n = 48 determined by Koulischer et al (1972). Marleni came from Lampung and arrived at Ragunan Zoo in 1994 (table 4). It was not possible for us to identified Marleni to the species.

Our result suggest that Marleni should be regarded as a different species, from that of high land and low land anoa due to chromosomal differences observed between those species.

The cromosome number of Poso whose head resembles that of cattle (table 4) A. depressicornis is 48(2n). The general choromosome morpology is in agreement with that described by Hsu and Bernischsee (1974).

The crossing of Buton (A. quarlesi) and Marleni is particulary important for cytogenetic research because both parent species possess different karyotypes (table 3).

The number chromosome of Bone could not be ascertained.

Anoa from Central Sulawesi (Ngeek ngeek and Kaledo; Table 2) whose heads resemble that of the sheep, with white head and white body, (Utami et. al 1996) the karyotype analysis has not been finished , yet.

Discussions

The primary goal of the captive anoa population is to reduce the risk of extinction of this species. Genetic variation is the essence of life (Benirschke 1985) and since there exists little doubt now among most zoo professionals the availability of wild animals for exhibition is in serious jeopardy.

The two sibling animal A. quarlesi and A. depressicornis, is a well known on how two species with very similiar external morphology can have completely different karyotypes. The basic thrust of conservation genetic is to maintain genetic diversity and thus preserve evolution. Cytogenetic analysis of the anoas had been performed before captive breeding in Ragunan Zoo.

The variation of colour pattern found in anoas is only a variation and specific feature of a species.

The characteristics of Bone (male) could not be identified with chromosome number is 42 (2). The sire is Buton and dam is Marleni (Table 3).

Marleni (female) could not be identified, with chromosome number is 38 (2n). It had been found that Bone and maybe Marleni are bred in Zoo posessed different chromosome complements.

And, next Bone will be used for research study and education program. It is also necessary to recheck the ancestor of Marleni.

Chromosomal analysis makes clear distinction between hybrids and "pure" specimen, which is not always possible by phenotype alone, especially for young animals (e.g. Bone and Kaledo). By undertaking such chromosomal study it is possible to prevent breeding of and from hybrid animals in zoo.

Aside from the practical aspects that cytogenetic studies have for genetic management and conservation, further chromosomal information is needed to unravel the mechanisms of speciation ("fusion versus fission").

Out of approximately 195 species of artiodactyls, 115 (60 %) have had some degree of karyotype study, clearly an inadequate number. Moreover future efforts are needed in obtaining banded preparations of most taxa already studied. The investigations of karyotypes in many gazelles have shown that some taxa have striking and consistent translocation between sex chromosome (X & Y) and spesific autosomes (Benirschke et al 1980). We have emphasized that for these and other animals it is essential that karyotypes be known before captive populations are established.

Reviewing the needs of genetic management in zoo brings out several immediate goals. Foremost, in the author's opinion, must be the conduct of scientific research in to the genetic composition of all anoa. This includes immediately at least the establishment of karyotypes, the long term conservation of cell strains, the methodical freezing of as wide a sample of gametes and tissue sample as possible.

In addition to carrying out genetic research on endemic animals it is essential that captive animals be bred in a manner following the best established genetic principles to avoid crossbreeding, inbreeding and genetic drift.

Genetic study must be managed for long term survival by maintaining identifications for each individual in the populations. It is very important to manage captive populations by maintaining identifications for each animal in the population, by cytogenetic studies and keeping records of parentage

Blood samples were kindly provided by Manager of Flora & Fauna, Curator Mammal veteriner and Keeper of Ragunan Zoo, Jakarta. We would like to express our sincere thanks to Drh. Sutarman MS, Madinah, Mad Sofi, and Drh. Bambang for their help.

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