Abstract
A new species of the genus Hynobius is described from the western part of Aichi Prefecture, Japan. Hynobius vandenburghi can be divided into two groups, the Aichi and Kinki groups, based on molecular and morphological analyses; thus, we described the Aichi group of H. vandenburghi as a new species, Hynobius owariensis sp. nov.. Morphological comparisons revealed that although male H. vandenburghi have distinct bright yellow lines on the dorsal and ventral sides of the tail, males of the new species do not. Additionally, in males, the new species usually has fewer costal folds between its adpressed limbs than are observed in H. vandenburghi. Other significant differences in several morphological characteristics were also found between H. vandenburghi and the new species, and results of discriminant analyses between the two species in both sexes suggested that they are separated in terms of morphological data. The new species is restricted in the western part of Aichi Prefecture, which is threatened with extinction by artificial development or reformation of well-drained paddy fields.
