Freshwater snails (Mollusca: Gastropoda) of fish ponds in Silesia (southern Poland)

The paper presents results of studies on the snail fauna of 22 fish ponds of Silesia and its vicinities. 20 species were found. The results suggest that neither the size and depth of a reservoir nor the bottom type effect directly particular snail species. It seems that the impact of these factors is overlapped or modified by cultivation which limits the number and species diversity of snails. As regards ponds in the Upper-Silesian Industrial Region, another limiting factor is industrial water pollution.