Molecular Phylogeny of Asian Freshwater and Marine Stingrays Based on the DNA Nucleotide and Deduced Amino Acid Sequences of the Cytochrome b Gene

Abstract

To elucidate the phylogenetic relationship among stingrays of three freshwater and five marine species of the genera Himantura, Dasyatis, and Pastinachus, belonging to the family Dasyatidae distributed in Thailand, Laos, India, and Japan, we determined the nucleotide sequences of the mitochondrial DNA region encoding cytochrome b. Using two rayfish species belonging to the superfamily Myliobatoidea as out-groups, we found three clades for the collected stingrays in the family Dasyatidae from anlayses using the neighbor-joining, maximum parsimony, and maximum likelihood algorithms. While species belonging to the genus Himantura formed one group, Dasyatis laosensis and Dasyatis sp. formed another group. The results obtained failed to show clear phylogenetic relationships of the genus Pastinachus with the genera Dasyatis and Himantura, since the corresponding bootstrap resampling values were 72, 55, and 65 in the neighbor-joining, maximum parsimony, and maximum likelihood trees, respectively.