The database contains information about 270 shelled Gastropoda (both native and alien). Information is avaialble in 4 data-files: macrohabitat preference, microsites features, traits, range and degree of endemism. Glossareis are available to unterstand the precise innterpretationon terms used. Fuzzy coding is applied (0-3), which describes the association between a species and a variable. More information on this dataset can be found in the Freshwater Metadatabase - BF27 (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BF27).