Distribution
Europe: north to Pyrenees and Alps, eastward to Ural and Eya drainages (Caspian basin); Aegean basin in Pinios, Vardar, Vegoritis, Kastoria, Struma and Maritza drainages. Asia: Marmara basin and lower Sakarya in Anatolia, Aral basin, and Siberia from Ob eastward to Lena drainages. Naturally absent from Iberian Peninsula, Adriatic basin, Italy, Great Britain north of 56 N, Scandinavia north of 69? N. Locally introduced in Spain; introduced and invasive in northeastern Italy. At least one country reports adverse ecological impact after introduction.