Fauna of ciliates (Alveolata, Ciliophora) of the southern part of the Russian Far East

This paper presents information on the distribution of ciliates in freshwater bodies and soils of the southern part of the Russian Far East. During the study, 307 species of ciliated protozoa were registered, 59 of which were identified only to the genus level. The greatest species richness was observed in biotopes of the southern part of Sakhalin Island, watercourses of Primorye, and soils of Middle Priamurye. The core of the ciliate communities (65%) belonged to the classes Oligohymenophorea (86 species), Spirotrichea (69), and Litostomatea (44). In general, faunal diversity of ciliates in natural water bodies was richer than that in anthropogenically transformed water basins. The habitat conditions of ciliates in wastewater treatment plants were not very diverse since some ecological factors therein were artificially controlled by humans. The coefficient of faunistic similarity of ciliates between the surveyed biotopes varied in a wide range (11.7-68.3%). We infer that this fact is caused by the following factors: significant distance between water bodies; similar origin (natural or anthropogenic) and/or belonging to the same river system; influence of some specific environmental factors. However, the zoogeographic analysis of the species community of ciliates from different regions of Russia and beyond did not confirm this hypothesis. During the study, several faunistic complexes of ciliated protozoa were determined in the studied region: eurytopic, including 11 species (Vorticella convallaria complex, V. microstoma complex, V. campanula, Tachysoma pellionellum, Aspidisca