EN
In the littoral of an oligotrophic Hańcza Lake molluscs were the second most abundant group (next to Asellus aquaticus (L.)) of invertebrate macrofauna on Characeae (17%–34% total abundance). Thirteen taxa were found, with a distinct dominance of Dreissena polymorpha (Pall.); in some sites the proportion of Valvata cristata O. F. Müll. or the genus Pisidium was considerable. A rare relict Marstoniopsis scholtzi (Schm.) was sporadic.