系统进化与生物地理学（杨君兴）知识库

A new species of the cyprinid genus PlacocheilusWu1977, is described from the Dulong River drainage (in the upper reach of the Irrawaddy River), northwestern Yunnan Province (China). Placocheilus dulongensis sp. nov. can be distinguished from the other three congeners, namely P. caudofasciatus, P. robustus and P. cryptonemus, by the following combination of characters: no semicircular black mark on the middle of each caudal fin lobe; no blackish band across the dorsal fin; one pair of rostral barbels and one pair of maxillary barbels; 39–40 perforated lateral line scales. Osteological characters, such as the shape of the

second infraorbital, preoperculum, and the vertical plate of the urohyal were observed in a cleared and stained skeletal specimen.Asimplified key to the genus Placocheilus is provided based on the comparisons

among the four species.