1. The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology; Chinese Academy of Sciences; Hubei Wuhan 430072 P. R. China
2. College of Fisheries; Huazhong Agricultural University; Hubei Wuhan 430070 P. R. China
3. Department of Ecology and Evolutionary Biology; University of Connecticut, 75 N. Eagleville Road; Storrs CT 06269-3043 U.S.A.
4. Department of Biology; Baylor University, One Bear Place #97388; Waco TX 76798 U.S.A.