Ciliates of some karstic lakes of the Middle Volga basin

The first data on fauna and structure of communities of ciliates in some karstic waterbodies in territory of the Middle Volga Basin (the rivers Ilet and Kazanka) are resulted. It is established, that a specific diversity and quantitative development of ciliates is reduced, ecological and trophic structure of communities change in the range: «fresh waterbodies - saltish waterbodies (stratified) - saltish waterbodies (not stratified) with intensive water cycle».