Ostracoda (Crustacea) from the Lowland Floodplain of the River Pripyat

Abstract

Ostracoda species richness was compared for various patches of Pripyat river catchment (so called Polesye), which covered about 30% of the territory of Belarus. Internationally the Pripyat is one of the least disturbed lowland rivers in Europe and its floodplain (to 10- 15 km wide) from the past is still present in nearly natural condition. The total Ostracoda list for 4 regions of the Pripyat catchment supports 51 species including rare species, which are more than 30% of the total species composition. The investigations of abundance and distribution of Ostracoda assemblages along the floodplain water body's lateral gradient was performed both in May-June and August of 1999 (in the middle river course). Species richness was equal to 42 and about 20% of the Ostracoda assemblage composition were rare species. Species number and rare species indices were increased at water bodies both with the biotope diversity and the underground water upwelling influence made out with hydrochemical data. The analyses of the abundance and ecological patterns of Ostracoda species demonstrated the ecological groups, which inhabited various water bodies in the gradient from a riverbed to the floodplain margin.