A new species of Triplophysa (Cypriniformes, Nemacheilidae) from Weihe River in Gansu Province, China.

A new species of Tibetan loach, Triplophysa weiheensis sp. nov., is described from the Weihe River in Gansu Province, China, based on morphological and molecular analyses. The new species can be distinguished from all known congeners by a unique combination of the following characters: scaleless; snout abruptly sloping downward, anterior to anterior nostril; lower jaw crescentic, not sharp; body without obvious mottling; lateral line interrupted on posterior trunk at pelvic-fin distal extremity; caudal-peduncle length 2.0-2.7 times its depth; branched rays of pectoral fin 10-11; branched rays of pelvic fin 5-6; inner gill rakers on 1 ^st gill arch 14-16; vertebrae 4+34-36; intestine with 6-7 loops, length ca. 1.8 times SL ( n =3); bony capsule of air bladder small and thin; posterior chamber of air bladder absent.