A New Cavedwelling Fish Species of Genus Triplophysa (Balitoridae) from Guangxi,China

A blind loach Triplophysa tianeensis sp.nov.(Holotype:KIZ 200301003,59.2 mm SL) has been recognized on basis of collections from an underground river of Hongshuihe in Tiane County,Guangxi,China,January 2003.Triplophysa tianeensis is closely related to T.gejiuensis,T.shilinensis,T.aluensis and T.nandanensis.It can be distinguished from T.gejiuensis and T.shilinensis by following characters:posterior end of pelvic fin not reaches anus vs.reaches;branched caudal fin rays 16 vs.14-15.Triplophysa tianeensis can be further identified from T.aluensis by following characters:dorsal fin origin at the middle point of the body vs.dorsal fin origin closer to snout tip than to caudal fin base;dorsal fin origin posterior of pelvic fin origin vs.dorsal fin origin anterior of pelvic fin origin;anus very close to anal fin origin vs.anus some distance from anal fin origin.Triplophysa tianeensis is most closely related and sympatric to T.nandanensis,but it can be easily distinguished from T.nandanensis by following characters:branched dorsal fin ray 7 vs.8,branched dorsal fin ray 9 vs.10-11;branched pelvic fin ray 6 vs.7;distal margin of dorsal fin truncate vs.emarginate;dorsal fin origin posterior of pelvic fin origin vs.anterior of.Furthermore,T.tianeensis has more prominent cave-dwelling features than T.nandanensis:eye highly degenerated,eye diameter 16.8-32.8 (25.0) times in head length vs.eye small but not degenerated,eye diameter 4.7-9.0 (7.5) in head length;without pigment on body and fins in large individuals vs.with densely cloudy blotches on head and body and with spots on fins.