A New Species of the Genus Tylototriton (Urodela: Salamandridae) from Northeastern Hunan Province, China

Abstract

We describe a new species from the family Salamandridae from northeastern Hunan Province of China based on morphological and molecular genetic evidences. The new species, Tylototriton liuyangensis, is a member of the T asperrimus group, and shares a number of similarities with T wenxianensis and T broadoridgus. The dorsal surface of the new Tylototriton species is completely black, with nodule-like warts distributed evenly along the lateral margin of dorsal body, and there is no transverse striae between the warts. There are several diagnostic characters of the new species that differ from those of T wenxianensis and T broadoridgus as follows: (1) the interorbital space (IOS) is comparatively wide; (2) there is a bony ridge present on the dorsal head surface, running along the upper eyelids; (3) the space between axilla and groin (AGS) is comparatively large, with the mean male AGS approximately equal to 50% of the snout-vent length (SVL) and the mean female AGS being 53% of SVL; and (4) there is a small genital armature on the anterior angle of labial folds present inside the anal fissure of adult males during the breeding season. The result from the molecular phylogenetic analysis of the genus Tylototriton (including the type specimen of the new species) based on the complete DNA sequence of the mitochondrial ND2 gene (1035 bp) indicated that the new species was similar to T wenxianensis, T dabienicus, and T broadoridgus, but formed an independent clade. This result was consistent with the morphological analysis above, supporting that the Liuyang Population represented a distinct species.