Distribution
Europe: Basins of Black (Danube, Dniestr, South Bug and Dniepr drainages), southern Baltic (Nieman, Odra, Vistula) and southern North Seas (westward to Meuse). Invasive or introduced in Rh?ne, Loire, H?rault, Seine (France) and Soca (Italy, Slovenia) drainages. Reports from the Drin drainage including Lakes Ohrid and Skadar represent a distinct species. In Appendix III of the Bern Convention (protected fauna).