广西高原鳅属鱼类一穴居新种记述

2003年1月，在广西壮族自治区天峨县红水河水系地下河采集到一批盲鱼标本。经鉴定，为高原鳅属Triplophysa一未经发表的新种。新种天峨高原鳅Triplophysa tianeensis sp．nov．与个旧盲高原鳅T．gejiuensis、石林盲高原鳅T．shilinensis、阿庐高原鳅T．aluensis和南丹高原鳅T．nandanensis相似；本新种腹鳍末端不达肛门，尾鳍分枝鳍条16，可进一步与个旧盲高原鳅和石林盲高原鳅(腹鳍末端达到肛门，尾鳍分枝鳍条14-15)相区别；本新种背鳍起点位于体之中点、腹鳍起点之后，肛门紧靠臀鳍起点，可进一步与阿庐高原鳅(背鳍起点靠近吻端、位于腹鳍起点之前，肛门距臀鳍起点仍有一段距离)相区别。本新种与同分布于红水河水系的南丹高原鳅Triplophysa nandanensis Lan et al.较为相似；但二者区别明显：新种背鳍分枝鳍条7、胸鳍分枝鳍条9、腹鳍分枝鳍条6、背鳍外缘平截、背鳍起点位于腹鳍起点之后，后者背鳍分枝鳍条8、胸鳍分枝鳍条10～11、腹鳍分枝鳍条7、背鳍外缘凹入、背鳍起点位于腹鳍起点之前；此外，新种的穴居特征更为显著：眼极度退化、头长为眼径16．8—32．8(25．0)倍、部分个体无色素斑且各鳍无斑点，而南丹高原鳅眼小、头长为眼径4．7～9．0(7．5)倍、体和头背侧密布云状斑且各鳍均具点状斑。

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 Tian'e 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.