Identification of leopard frogs (Anura: Ranidae: Lithobates) distributed in some localities of the Southern Mexican Plateau using mitochondrial DNA sequences.

Abstract

Species of the genus Lithobates are difficult to identify, especially on the 'Rana pipiens' complex, because the morphological differences among the species are often subtle. In this study, we used 12S ribosomal RNA gene partial sequences to identify specimens of leopard frogs from some new localities (not sampled on previous studies) of the Southern Mexican Plateau, to carry out a phylogenetic analysis, and also a morphometric analysis of some morphological features were analyzed to evaluate their morphological variation. A phylogenetic analysis using partial sequences of 12S rDNA mitochondrial gene for 31 samples was carried out using Bayesian Inference, Maximum Parsimony, and Maximum Likelihood. In addition, 20 morphological lineal measurements from 97 specimens were analyzed by principal component analysis (PCA) to evaluate if the frogs studied are conspecific. Partial sequences of the 12S rDNA obtained from frogs distributed in the Southern Mexican Plateau show two haplotypes with a divergence of 0.4%. Phylogenetic hypothesis shows an exclusive group with a previous sequence of Lithobates montezumae. The PCA indicates that variables are not linearly correlated and specimens belong to a single group. Evidence found, let us consider that specimens studied belong to one species of the Lithobates montezumae subgroup, distributed principally in the Southern Mexican Plateau.