A New Salamander of the Genus Onychodactylus from Central Honshu, Japan (Amphibia, Caudata, Hynobiidae)

Abstract: The number of species of salamanders of the genus Onychodactylus in Japan has increased from one to six nominal species over the past decade, by taxonomic studies based not only on morphological but also molecular phylogenetic data. However, the presence of an additional cryptic species has been suggested by a series of previous studies. Here, we describe a new species, Onychodactylus pyrrhonotus sp. nov., from the Kinki, Chubu and Hokuriku Districts of central Honshu, Japan, based on morphological and genetic evidence. It belongs to the O. japonicus species complex and is the sister species of O. kinneburi from Shikoku Island and westernmost part of Honshu with 5.5% sequence divergence in the mitochondrial cytochrome b gene. The range of the new species completely overlaps with that of O. japonicus sensu stricto, and they are syntopic in at least six known localities. As shown in a previous study, reproductive isolation between these sympatric species is substantial. The new species is morphologically most easily distinguished from congeners by coloration, a sharply defined scarlet to pinkish dorsal stripe or mottling on a black background and dusty white dots on the venter.