Species diversity and ecology of water mites (Hydracarina, Hydrachnidia) of the main rivers of the “Yugyd va” national park (Pechora river basin)

Water mites (Hydracarina) in the main rivers of the Yugyd Va National Park, the Shchugor River (Northern Urals) and the Kozhim River (sub-Polar Urals) are well-distributed bottom invertebrates, that inhabit all biotopes but prefer plants (mosses and filamentous organisms) on pebble-boulder grounds. The list of water mites in the national park numbers 48 species and varieties of seven families, among which 43 species and varieties inhabiting the Shchugor River and 30 - the Kozhim River. The similarity coefficient of Hydracarina species composition for both rivers is equal to 68.5% (by Syerensen). Most numerous are the families of Hygrobatidae (18) and Sperchonidae (13) which are normally met with running water-bodies. Fauna of water mites was found for zoogeographical heterogeneity which is of a holarctic-palearctic kind and includes northern and Siberian species. Holarctic species are Sperchonopsis verrucosa, Sperchon glandulosus, Lebertia porosa, Hygrobates longipalpis, Feltria minuta. The core of Hydracarina fauna is composed of well-distributed palearctic species Sperchon brevirostris, Hygrobates calliger, H, fluviatilis, H. foreli, Atractides nodipalpis, etc. The specific feature of water mites in the park which is situated on the boundary between the European and the Asian parts is the presence of the European species Mesobates forcipatus being absent in Siberia, the Siberian species Mixobates uncatus, Sperchon tridentatus being normally absent in Europe and the variety of Atractides nodipalpis constrictus being typical of the Far East. The species Sperchon glandulosus cubanicus, Lebertia pusilla, L. ignatowi which were found in the rivers are considered to be rare for the European water-bodies. Based on our benthos collections from the Kozhim River and the Shchugor River, the famous acarologist Dr. P.V. Tuzovsky described absolutely new species as Feltria tsemberae Tuzovskij, 1999 and Aturus polyporus Tuzovskij, 2009.