<br> Schizopygopsis malacanthus<br> Herzenstein, 1891, a fish species native to the Qinghai-Tibetan Plateau, is widely distributed upstream of the Jinsha and Yalong Rivers. Comprehensive analyses were conducted on all geographic populations of<br> S. malacanthus<br> and the coexisting fish<br> Herzensteinia microcephalus<br> (Herzenstein, 1891). Morphological examination revealed that the Yalong River population of<br> S. malacanthus<br> can be distinguished from other<br> Schizopygopsis<br> species according to its phenotypic characteristics, including the origin of the ventral fin under the 4<br> th<br> –5<br> th<br> branched ray of the dorsal fin, strong unbranched rays of the dorsal fins, hooked pharyngeal bones, and shovel-shaped or oblique-truncated grinding surfaces of the pharyngeal teeth. The phylogenetic and genetic analyses revealed monophyly of the Yalong River population of<br> S. malacanthus<br> , with genetic distances ranging from 2.03––6.16% from those of other<br> Schizopygopsis<br> species. Consistent with the molecular evidence, species delimitation clearly revealed that the Yalong River population of<br> S. malacanthus<br> is distinct from other<br> Schizopygopsis<br> populations. Therefore, we present<br> Schizopygopsis yalongensis<br> sp. nov.<br> as a valid species through integrative taxonomy, resolving the taxonomic ambiguity of the<br> Schizopygopsis<br> fishes in the Yalong River. These results increase known fish diversity and highlight cryptic species present in the river system of the Qinghai-Tibetan Plateau.<br>
