Phylogenetic and Systematic Study of the Genus Bombina (Amphibia: Anura: Bombinatoridae): New Insights from Molecular Data

Abstract

Phylogenetic relationships and systematics of the eight currently recognized species of the genus Bombina were investigated using four mitochondrial gene fragments (16S rRNA, 12S rRNA, ND4-tRNALEU, and cytochrome b). We prepared two different concatenated datasets: (A) 12S 16S; and (B) Cytb ND4-tRNALEU 12S 16S. Partition-homogeneity tests indicated that these combined datasets were homogeneous, and phylogenetic analyses (Bayesian inference, maximum parsimony, neighbor-joining and maximum likelihood) were performed on them. All phylogenetic analyses based on combined dataset A recover two major clades within the genus Bombina (although one of them was weakly supported): a clade corresponding to the subgenus Bombina; and another clade corresponding to the subgenus Grobina. The hypothesis that Bombina orientalis was the sister group of Bombina maxima is rejected by our results. Our results support the monophyly of the southwest China taxa and the validity of Bombina lichuanensis as an independent species. Considering the low genetic differences among the southwest taxa, and previous morphological and karyological evidence, we suggest that Bombina microdeladigitora and Bombina fortinuptialis might be reassigned as subspecies of B. maxima.