On the occurrence of populations of the genera Cobitis and Sabanejewia (Pisces, Cobitidae) in the Czech Republic

We examined the occurrence of species within the genera Cobitis and Sabanejewia in the water bodies of the Czech Republic. Currently Cobitis elongatoides and its hybrid polyploid complexes are associated with the River Dyje and its floodplain (Danube basin), with the upper part of the River Luznice drainage area (including its fishpond area) and, further on, with the central area of the River Elbe. Populations of C. elongatoides and Sabanejewia balcanica which had been reported previously in the literature were absent from those localities. The principal factors were polluted waters, modification and regulation of water stream channels and also dam constructions. At present, C. elongatoides is considered to be critically endangered while S. aurata is no longer found in the Czech Republic.