Revisiting the Species Delimitation Within Amolops mantzorum (David, 1872), with a Description of a New Subspecies (Anura, Ranidae)

Accurate species delimitation benefits detailed biological descriptions and conservation practices. In this study, we focus on a frog species distributed throughout the western edge of Sichuan Basin, China, the Sichuan torrent frog-<i>Amolops mantzorum</i>. Currently, <i>A. mantzorum</i> is recognized as comprising two subspecies-the nominate subspecies <i>A. m. mantzorum</i> and <i>A. m. xinduqiao</i>. We investigated a population from along the Yalong River, Sichuan Province, China which was previously overlooked in phylogenetic studies. Combining multiple mitochondrial genes (<i>16S</i>, <i>CO1</i>, <i>cytb</i>), we identified four distinct lineages within <i>A. mantzorum</i> using Bayesian inference and maximum likelihood phylogeny. Principal Component Analysis based on morphometrics revealed significant differences between the population from along the Yalong River and the other two subspecies for which morphological data were available. Combined with detailed morphological descriptions and comparisons, here we describe this population as the third subspecies of <i>A. mantzorum</i>-<i>Amolops mantzorum feiye</i><b>ssp. nov.</b>