Related affecting factors in community structure characteristics of the crustacean assemblages in Yueqing Bay

Based on the trawl data of fishery resources collected from comprehensive surveys from May 2016 to February 2017 in Yueqing Bay, species composition, biodiversity index, community structure and its relationship with environmental factors were examined by cluster analysis, multivariate statistical analysis and redundancy analysis. The results showed that a total of 43 species of crustacean were identified, which belonged to 28 genera, 18 families and 2 orders. Portunus trituberculatus, Charybdis japonica and Parapenaeopsis hardwickii were annual dominant species. The species number of crustacean was the greatest in summer and the least in winter which varied significantly in four seasons, while the composition of dominant species changed slightly. The research about crustacean species at different depth indicated that the richest crustacean were at depths of 5~10 m while fewer species at depths of less than 5 m and more than 10 m. The results of One-Way ANOVA showed that the richness index (D) of crustacean community at different depth were distributed significantly, and there were no significant differences in evenness index (J') and diversity index (H'). Redundancy analysis suggested that temperature, depth and turbidity were the most important environmental factors affecting the crustacean species composition and community structure characteristics. In particular, the depth has a great influence on the community structure of crustacean.