1. Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Key Laboratory of Aquatic Science of Chongqing, School of Life Science, Southwest University, Beibei, Chongqing, P.R. China and
2. Yangtze River Fisheries Research Institute of Chinese Academy of Fishery Science, Scientific Observing and Experimental Station of Fishery and Environment in the Upper and Middle Reaches of the Yangtze River, Ministry of Agriculture, Wuhan, Hubei, P.R. China