A cryptic species of the Amolops ricketti species group (Anura, Ranidae) from China-Vietnam border regions

It was supposed that the current records of Amolops ricketti might be a species complex composed of multiple species. In this study, on the basis of wide sampling, we found that the records ofA. ricketti from Yunnan, China, and northern Vietnam actually represent a cryptic species based on morphological and molecular evidence. Amolops shihaitaoi sp. nov. can be distinguished from other members of the A. ricketti species group by its moderate body size (SVL 35.5-37.3 mm in males and 39.2-45.7 mm in females); white spines on the temporal region, loreal region, snout, and lips in breeding males but absent in females; overlapping heels; tibiotarsal articulation reaching tip of snout; indistinct longitudinal glandular folds on the skin of the shoulders; presence of supernumerary tubercles below the base of fingers II-IV, distinct pineal body; presence of vomerine teeth; and absence of vocal sacs. Phylogenetic analysis supports that the new species is sister to Amolops yatseni and the populations from Jingxi, Guangxi and Lao Cai, Vietnam previously reported as A. yatesni also belong to it. Additionally, our results indicate that more cryptic species may exist within the A. ricketti species group, implying that more studies are needed to achieve a complete understanding of the species diversity of this group.