Distribution
Europe and Asia: most of Europe north of Caucasus, Pyrénées and Alps, eastward to Ural and Emba. Naturally absent from Iberian Peninsula, Adriatic and Aegean basins (except Maritza drainage), Italy, Ireland, Great Britain (except southeast), Norway and Scandinavia north of 67°N, Caspian basin south of Volga. In Anatolia, Marmara basin. Locally introduced in Spain, Portugal and Italy. At least one country reports adverse ecological impact after introduction.