Rheophilic communities of macrobenthos of the southwestern Kola Peninsula

The fauna and diversity of macrozoobenthos communities in watercourses of the Khibiny tundras, the surrounding plains, and the Kandalaksha Coast of the White Sea (Murmansk oblast) are described from materials collected by the authors. A checklist of 110 recorded taxa is given, with larvae of Diptera, Trichoptera, Ephemeroptera, and Plecoptera prevailing. A total of 21 types of macrozoobenthos communities are described and subdivided into two parallel series: cold mountain reaches (11 types) and relatively warm plain reaches (10 types). The boundary between them is marked by summer water temperatures of 12-14A degrees C and usually associated with flowing lakes passing through the watercourses in foothill areas. Changes in bottom communities along the longitudinal profile of watercourses of the region are considered; the main factor here is also the summer water temperature, but the basic assumptions of Vannote's river continuum concept or Illies's longitudinal watercourse zonality concept are not met. The fauna of the plain part of the water-courses of the region is similar to those of other regions of Eastern Europe, from the south to Moscow oblast, but the mountain series with its peculiar and strongly depleted fauna deserves recognition as a separate zoogeographic province.