Abstract
We surveyed allozymic variation among Hynobius naevius from 11 localities of central Kyushu, Japan. The results revealed the presence of two genetic groups (I and II) that exhibited a great difference in allelic frequency and a large genetic distance. Specimens from seven of the 11 localities invariably belonged to Group I, and those from three other localities belonged to Group II. In the remaining one locality, representatives of both of these two groups were found just as in northern Kyushu. The two genetic groups also differed in morphological (Group I larger than Group II in body size) and ecological characters (breeding sites located in open streams in Group I, but possibly in underground water in Group II). These differences might have been enabling them to coexist.
