Freshwater sponges (Porifera, Spongillidae) from the Lake of Geneva, Switzerland

A census of the sponge fauna in shallow-waters of the Lake of Geneva, Switz erland, displayed the presence of scattered populations of Spongilla lacust ris (Linnaeus, 1758), Eunapius fragilis (Leidy, 1851), Ephydatia fluviatili s (Linnaeus, 1758), and Ephydatia muelleri (Lieberkuhn, 1855). Spongilla la custris was the most frequent species, either alone or associated with othe r species it was present in numerous sites on a variety of substrata along the entire shoreline. The morphological analysis of specimens of S. lacustr is of the Lake of Geneva compared with the type material of S. lacustris an d Spongilla helvetica, shows a considerable Variation of skeletal and gemmu lar characters. Therefore, the synonymy of S. helvetica with S. lacustris i s confirmed. The study also demonstrates the existence of a rich and divers ified sponge fauna in the Lake of Geneva.