Sinocyclocheilus sanxiaensis, a new blind fish from the Three Gorges of Yangtze River provides insights into speciation of Chinese cavefish

DEAR EDITOR,A blind fish of Sinocyclocheilus (Cypriniformes: Cyprinidae)was caught in open water in the Three Gorges (Sanxia)reservoir, at a depth of 20 m in the mainstream of YangtzeRiver in Zigui County, Hubei Province, China. This fish can beeasily distinguished from all other congeners by externalmorphological characteristics, and is estimated to havediverged from its sister group about 0.55 million years ago(Ma). The geologically well separated locality of this specieshas expanded the distribution of Sinocyclocheilus cavefishfrom around N25°(latitude) to above N30°. Herein, wedescribe this new species as Sinocyclocheilus sanxiaensis sp.nov., and discuss the possible reasons why the speciesappears, surprisingly, in the Three Gorges reservoir.