Occurrence of a Lotic Breeding Hynobius Salamander (Amphibia, Urodela) on Kamishima of the Amakusa Islands, Japan

Abstract

We found a salamander of the genus Hynobius on Kamishima of the Amakusa Islands, Japan, which is new to this island group. From the characteristics of larval habitat and morphology, this salamander is considered to be a lotic breeder. Until the discovery of this species, only a lentic breeding species (Hynobius nebulosus) was known from the Amakusa Islands. Morphologically the present salamander is well differentiated from other lotic breeding Hynobius of nearby regions and is closest to the southernmost population of H. boulengeri from the Osumi Peninsula among the species or populations examined. In order to determine its taxonomic position, however, genetic analyses using a larger number of comparative specimens are needed. The biogeographic significance of the present finding is briefly discussed.