Identification of Testate Amoeba Communities and Their Influencing Factors in Dali Lake

The shells of testate amoebae are decay-resistant and well preserved in lake sediments, making them excellent biological indicators of climate change. In this study, the identification method for testate amoebae was initially optimized based on the collection of surface sediments from Dali Lake, and statistical analyses were conducted to investigate the community distribution characteristics and key environmental factors driving the testate amoeba species composition. According to the results, the testate amoeba species diversity in the surface sediments of Dali Lake was relatively low. A total of eight species belonging to five genera were identified, and the dominant species were Arcella discoides (35.64% of the total abundance), Phryganella acropodia (24.75%), and Arcella gibbosa (11.39%). All the identified testate amoeba taxa are common in global freshwater sediments, and no new species was discovered in this study. The testate amoeba community composition exhibited strong correlations with the total organic carbon, total nitrogen, dissolved inorganic phosphorus, and total phosphorus and weak correlations with the electrical conductivity and Chlorophyll-a.