May have been introduced (Ref. 74657). Migrated from the Danube to the confluence of the Dyje and Morava rivers after 1975. Has competed heavily for food and space with C. carassius populations, Tinca tinca, Leucaspius deliniatus, and other native cyprinids thereby decreasing its populations. Presently the most dominant fish species in lenitic and slowly running aquatic habitats (Ref. 83969). Also Ref. 54732.