Abstract: To analyze the characteristics of metazooplankton functional groups and their relationship with water environmental factors in Qingcaosha Reservoir, a monthly sampling survey was conducted in 2021. A total of 47 metazooplankton species were collected and divided into 9 functional groups. The average annual biological density of metazooplankton was 82.4 ind/L, and the average annual biomass was 0.3460 mg/L. Rotifers carnivore(RC), middle copepods and claocera filter feeders(MCF) and large copepods and claocera filter feeders(LCF) constituted the main part of the total zooplankton biomass in Qingcaosha Reservoir. Pearson analysis showed that small copepods and claocera carnivore(SCC) had a significant correlation with middle copepods and claocera carnivore(MCC) and small copepods and claocera filter feeders(SCF) (P<0.05), and the functional group SCF, SCC, MCF, and MCC had a significant correlation (P<0.01), while RC and rtifers filter feeders(RF) showed no significant correlation (P>0.05). Redundancy analysis showed that in addition to functional group RC, LCF and LCC, other functional groups were significantly negatively correlated with water depth and dissolved oxygen, and positively correlated with water temperature. Total dissolved solids and ammonia nitrogen were significantly positively correlated with functional group RC and LCC, and significantly negatively correlated with functional group LCF.

Key words: Qingcaosha Reservoir, metazoan zooplankton, functional group, water environmental factors, temporal and spatial variation