[1] Univ Gdansk, Dept Mol Evolut, PL-80308 Gdansk, Poland
[2] Inland Fisheries Inst Olsztyn, Dept Salmonid Res, PL-83330 Rutki, Zukowo, Poland
[3] Univ Warmia & Mazury, Dept Ichthyol, PL-10719 Olsztyn, Poland
[4] Univ Gdansk, Dept Marine Biol & Ecol, PL-81378 Gdynia, Poland