Abstract: We investigated metazooplankton community structure and water environmental factors in Liujiaxia Reservoir from March to October 2020. Metazooplankton community structure and its relationships with environmental factors were analyzed by redundancy analysis, aiming to provide reference for water protection and sustainable utilization of fisheries in Liujiaxia Reservoir. A total of 24 species of zooplankton were identified, including 12 species of rotifers, 7 species of cladocerans, and 5 species of copepods. There were 16 species of zooplankton in summer and 11 species in spring. The dominant species were Keratella cochlearis, Polyarthra trigla, Asplanchna priodonta, Daphnia longispina, Daphnia cucullata, Bosmina longirostris, Sinocalanus dorrii and nauplius, with seasonal variations. The density of zooplankton varied from 8 to 116 ind·L^-1, with an average density of 31 ind·L^-1. The biomass of zooplankton varied from 0.056 to 0.606 mg·L^-1, and the average biomass was 0.280 mg·L^-1. The Shannon index, Margalef richness index, and Pielou evenness index were 0.77-1.87 (1.55 on average), 1.90-3.07 (2.56), and 0.20-0.55 (0.44), respectively. The lowest values of all the three diversity indices were found in September. Results of redundancy analysis showed that environmental factors such as water temperature, transparency and nitrate content were significantly related to zooplankton community structure. Water body of Liujiaxia Reservoir was at an oligotrophic level, which accords with the China’s national class II water quality standards.

Key words: metazooplankton, community structure, environmental factor, Liujiaxia Reservoir, redundancy analysis.