Unintentional introduction of aquatic molluscs from Poland to Prague (Czech Republic)

The aquatic mollusc populations of a restored water reservoir N1 – Stodůlky (Prague Capital City, Czech Republic, Elbe River Basin) were studied during 2005. Two visits, one and two months after inundation of the reservoir revealed rapid colonisation by 14 species of aquatic molluscs and the introduction of eight species (Valvata macrostoma, Stagnicola palustris s. str., S. corvus, Planorbis planorbis, Bathyomphalus contortus, Anisus spirorbis, A. septemgyratus, Segmentina nitida) from a site in north-western part of Poland (Tuchola region, Wisla River Basin about 450 km distant). These molluscs were transported on coir rollers and matting which were used for stabilisation of the reservoir banks during restoration