Taxonomic and spatial structure zoobenthos of the transboundary (Belarus-Latvia) lake Sita

Abstract

The zoobenthos of the cross-board (Belarus-Latvia) lake Sita was studied. The registered 47 taxa of benthic fauna from the species and taxa above the species. The bottom fauna includes a protected relict species Pallaseopsis qudrispinosa, listed in the Red book of Belarus. Chironomid larvae formed the basis of the abundance and biomass excluded molluscs. The lake belongs to mesotrophic type according to the average abundance and biomass zoobenthos. Spatial heterogeneity has been established in the depth distribution of the entire community, individual groups, and species. Taxonomic diversity decreased with increased depth, fall of temperature and oxygen concentration. Abundance grows from the littoral to a depth of 10 meters and then gradually decreases to the maximum depth. The biomass was determined largely by the presence of molluscs, maximum values are marked at depth 5,4 meters. The population of the species is confined to certain depths. For closely related species, there is a partial or complete division of ecological niche.