Abstract:

base on the catch data of set net in 2010, study on fish composition and seasonal change of diversity was carried out in Changshu section of the Yangtze River. Fishes of 12 orders, 25 families and 60 species were collected in this area. Number of species belonging to Cypriniformes was the most and the second was fishes belonging to Perciformes. In each season , dominant species was mainly common fishes but not seasonal species. There is a good equilibrium among species and species with high dominance have not be discovered. Dominance curve base on individual number revealed that there is no distinct difference among four seasons and Spring and Spring almost had the same dominance. According survey of four seasons, fish diversity index was 2.30-2.49,whih showed a higher diversity level. There is no distinct change in diversity index among four seasons. Influence of artificial releasing and water resources adjusting on the fish community was also discussed in this paper.