Abstract: To explore the spatiotemporal variations of shrimp community diversity at the lower reaches of the Yangtze River, we investigated seasonal variations of shrimp community from September 2020 to August 2021. We collected 62.57 kg and 34922 individuals of shrimps, belonging to 10 species, 6 genera and 3 families. Macrobrachium was the dominant genus, containing 5 species, whereas the other five genera contained only one species each. Among them, there were two exotic species, Macrobrachium rosenbergii and Procambarus clarkii. A significant difference of shrimp community was observed among seasons and sites. Species number, quantity, and weight of shrimp in Anqing section were 10, 17815 individuals, and 32.55 kg, respectively, which were significantly higher than those of the other sections (P<0.05). There was no significant difference of richness index among different sections (P>0.05), but differences of diversity index and evenness index among different sections (P<0.05). Species number, quantity, and weight of shrimp in summer were 9, 15748 individuals, and 26.23 kg, respectively, which were significantly higher than those in the other seasons (P<0.05). Evenness index in spring was significantly higher than that in the other seasons (P<0.05), while there was no difference in diversity index and richness index among seasons. According to cluster analysis, the lowest shrimp community similarity was observed in Changshu section and in winter, respectively. The abundance/biomass curves of shrimp communities in Anqing and Zhenjiang sections crossed, indicating that these two sections were severely disturbed, while Dangtu and Changshu sections were hardly disturbed. In general, shrimp diversity was relatively low at the lower reaches of the Yangtze River, and the community was disturbed to a certain extent. Attention should thus be paid to the dynamics and protection measures of the shrimp community.

Key words: lower reaches of the Yangtze River, shrimp, diversity, community structure, spatiotemporal characteristics.