Abstract: To understand the biodiversity characteristics of rotifers in reservoirs with different nutritional status in Guizhou Plateau and their responses to changes in environmental factors, we investigated the physicochemical parameters of water, and community structure of rotifers in Hailong Reservoir, Langou Reservoir, Gupitan Reservoir and Wanfeng Reservoir in October 2020, April, June and August 2021. Data were analyzed using the methods of trophic level index (TLI), non-metric multidimensional scaling (NMDS) and redundancy analysis (RDA). The results showed that 37 rotifer species were detected in the four reservoirs, with 25, 25, 30, and 22 species in Hailong Reservoir, Langou Reservoir, Goupitan reservoir, and Wanfeng Reservoir, respectively. There were 16 dominant rotifer species, including Keratella cochlearis, Brachionus forficula, Polyarthra vnlgaris. The average abundance of rotifers in Hailong, Langou, Goupitan and Wanfeng reservoirs was 212, 568, 137 and 102 ind·L^-1, and the average biomass was 43.23, 41.19, 13.93 and 8.89 μg·L^-1, respectively. The average value of Shannon diversity index in Hailong, Langou, Goupitan and Wanfeng reservoirs was 1.09, 1.09, 0.92 and 0.83, and the average value of Margalef richness index was 1.30, 1.45, 1.12 and 0.94, respectively. The average values of Pielou evenness index was 0.62, 0.58, 0.60 and 0.55, respectively. The results of NMDS showed that the community structure of rotifers in mildly eutrophicated reservoir was significantly different from that in mesotrophic reservoirs in October 2020 and April 2021 (P<0.01). The results of RDA showed that chlorophyll a, total phosphorus, and water temperature were the main environmental factors affecting the changes of rotifer community in Hailong Reservoir, ammonium nitrogen, chlorophyll a and total phosphorus were the main environmental factors affecting the compositional changes of rotifer community in Langou Reservoir, and water temperature and transparency were the main environmental factors affecting the compositional changes of rotifer community in Goupitan and Wanfeng reservoirs.

Key words: Guizhou reservoir, rotifer, trophic state, biodiversity, environmental factor