Ciliates оf the Kandry-Kul lake (Republic Bashkortostan): composition, spatial distribiution, seasonal dynamics and ecological state of water body according to their community

Free-living ciliates assemblages were studied in Lake Kandry-Kul (Republic of Bashkortostan) in 2012. The ciliate fauna of the lake expanded considerably (from 90 to 137 species). It was found that a significant horizontal variability combined with a weak vertical heterogeneity of ciliate assemblages. Compared to 2010, the decline in species diversity due to strengthened dominance, nearly twofold increase of abundance, biomass and production, enhanced contribution of smaller species and a decrease in the fraction of mixotrophic ciliates indicate the trend towards increasing trophic level of the water body. An inverse relationship between saprobity values and fraction of mixotrophic ciliates was detected, that can probably be used in future studies to evaluate the state of aquatic ecosystems.