Phylogenetic relationships of brown frogs from Taiwan and Japan assessed by mitochondrial cytochrome b gene sequences (Rana : Ranidae)

Abstract

In order to assess phylogenetic relationships of Taiwanese brown frogs (Rana longicrus and the R. sauteri complex), the partial sequences (587 base pairs) of the mitochondrial cytochrome b genes were compared with six brown frogs from Japan (R. pirica, R. ornativentris, R. japonica, R. tagoi tagoi, R. tsushimensis, and R. okinavana). Resultant phylogenetic trees indicated a considerable genetic differentiation between R. longicrus and R. japonica in spite of their close morphological and ecological similarities. The R. sauteri complex includes two genetically distinct groups that are not consistent with current classification. One group including populations of Alishan (central Taiwan) and Sanyi (western Taiwan) seemed to be closest to R. tagoi and the presumptive common ancestor of these frogs is thought to have diverged very early. Another group including a population from Wulai (northern Taiwan) showed a sister relationship with R, tsushimensis and R. okinavana, both isolated on small islands of Japan. These Taiwanese and Japanese brown frogs as a whole form a monophyletic group, and separation of the R. sauteri complex as a distinct genus or subgenus Pseudorana was not supported.