Abstract2_2 (Hasumi)

Hasumi, M., and H. Iwasawa: Geographic variation in the number of teeth of the Japanese salamander, Hynobius lichenatus. Science Reports of Niigata University, Series D (Biology) 25: 1-17, March 1988.

Abstract: Using 283 males and 49 females of adult Hynobius lichenatus collected from 19 localities in northeastern Japan, transparent specimens of the skulls were made, and the number of sockets in each dental region was counted. Intra- and interpopulation variation was found in the shape of a series of prevomerine teeth. The relative frequency of specimens with no bend toward the inside at the extreme border of a series of median prevomerine teeth tended to increase with the distance from the middle of Niigata district. No difference according to sex was recognized in the number of prevomerine, maxillary-premaxillary, and dentary teeth in any sample site. A positive correlation was found between the snout-vent length and the number of prevomerine, maxillary-premaxillary, and dentary teeth in some populations. On the other hand, a considerable geographic variation was found in the number of prevomerine, maxillary-premaxillary, and dentary teeth. Furthermore, a clinal variation noted was that the greater the distance from the middle of Niigata district the smaller the number of these teeth was.