A new cave-dwelling loach, Triplophysa xichouensis from Yunnan, China

A new cave-dwelling loach of the genus Triplophysa, T. xichouensis, is described from an outlet of a subterranean river in Xisa Town, Xichou County, Yunnan Province, China.

The genus Triplophysa Rendahl 1933 is one of the largest groups in the family Nemacheilidae. According to the life history of fish in dark caves or groundwater partly or totally, the cave fish were divided into typical cave fish, atypical cave fish and occasionally cave fish. At present, 25 cave-dwelling species in the genus Triplophysa were described in China. Count the Triplophysa xichouensis has 26 cave-dwelling species.

Xichou County is a typical karst landform in the southwest region, there are more rich in groundwater resources.In September 2013, two specimens were collected by researchers from Kunming Institute of Zoology (KIB), also the Aquatic Biodiversity Research Group of Southeast Asia Biodiversity Research Institute (SEABRI), from a cave in karst areas of Xichou County, Yunnan Province. Subsequent examination showed that these specimens represent a new cave-dwelling species of Triplophysa, described here. It was named after the Xichou County, and published as A new cave-dwelling loach, Triplophysa xichouensis sp. nov. (Teleostei Nemacheilidae) from Yunnan, China on Journal of Fish Biology.

It can be distinguished from its congeners by the following characters: eyes highly degenerated to a very tiny black dot; dorsal-fin origin closer to snout tip than to caudal-fin base and anterior to vertical line of pelvic-fin origin; body smooth and scaleless; lateral line complete and straight, long, oval; intestine short, bending in zigzag shape behind stomach. A key for the cave-dwelling species of Triplophysa is provided.

This work was funded by National Natural Science Foundation of China (31272275), the Yunnan Province Science and Technology Programme (2013HB096) and Southeast Asia Biodiversity Research Institute, Chinese Academy of Science (Y4ZK111B01).

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Triplophysa xichouensis

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Triplophysa xichouensis

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The habitat of Triplophysa xichouensis