Species Identification of Captive Gibbons in Japan by Using Mitochondrial DNA （cytochrome b） Sequences

Abstract

　The gibbons inhabiting Southeast Asia and its vicinity are classified into about 20 species. In Japan, gibbons reared in zoos and research institutes are registered in the studbook managed by the Japanese Association of Zoos and Aquariums. Species identification based mainly on the phenotypic traits and recent major taxonomic changes required updates of the registration information. This study aimed to identify species of those gibbons using genetic information that grants objective identification and to update the registration information. Specifically, we determined the cytochrome b gene sequence (1,140 base pairs) of mitochondrial DNA for 153 gibbon individuals and identified their species by referring to the registered sequences of each gibbon species. Sequence information was unavailable to 14 individuals whose species were then identified based on their kin relationship to the 153 individuals mentioned above (10 individuals) or the genus-specific traits (four Symphalangus individuals). As a result, the species identities of several Bornean and Sumatran Hylobates individuals were updated. Among 153 gibbons with sequence data, four Hylobates individuals were unspecified due to the lack of the relevant reference sequences. In conclusion, in Japan, 1) the captive populations of Symphalangus syndactylus, Hylobates lar, and Hylobates pileatus can be maintained in the future, 2) the small population size for the remaining species will limit their survival, and 3) the present updated registration information will contribute to the future breeding management.