A new typical cavefish of the genus Triplophysa (Teleostei, Cypriniformes, Nemacheilidae) from the Jinsha River, Yunnan, China.

Abstract

Triplophysa baishuijiangensis sp. nov., a new cave-dwelling loach, was collected from an underground river outlet in Xiaoganxi Village, Yiliang County, Yunnan Province, China, situated within the core area of the Baishuijiang National Aquatic Germplasm Resources Reserve for Endemic Fish, part of the Hengjiang-Jinsha River system. The new species is distinguished from congeners by significant genetic divergence and the following combination of characteristics: vestigial eyes, absence of skin pigmentation, pelvic fin tip reaching the anus, complete lateral line, developed posterior chamber of the swim bladder, and dorsal fin rays iii-7. Phylogenetic analysis based on Cyt b positions this new species in the hypogean group of Triplophysa, increasing the documented cave species in the genus from 42 to 43. Triplophysa baishuijiangensis sp. nov. represents the first documented typical cavefish in the Jinsha River basin, underscoring the region's ecological significance for subterranean adaptation and suggesting unexplored cave biodiversity that merits systematic investigation.