Maximum likelihood tree based on COI gene. Numbers above and below the branches are posterior probabilities and bootstrap support values (1,000 iterations), respectively. Three clades (I, II, and III) were recovered, the current sequences from the peninsular nested in clade I and sequences from northern Vietnam and northern Thailand nested in clade II therefore represent two subspecies R. a. superans and R. a. macrurus, respectively. None of the current sequence data nested in clade III. The later comprised all sequences from the GenBank and may represent a different taxon.