Alien fish species in the Czech Republic and their impact on the native fish fauna.

The article discusses research on the effects of alien fish species on the native fish fauna of the Czech Republic. Researchers found out that the non-native species have affected the native ichthyofauna in terms of ecological, biological, properties, biodiversity, as well as health. Species like Carassius gibelio lower the occurrence and numbers of indigenous carassius population and contributed to the decreasing numbers of Tinca tinca, Leucaspius delineatus, and other native cyprinid fish. The study also revealed that compared to other non-native fish species, Pseudorasbora parva and Ameiurus nebulosus have a much weaker and limited impact on native fish fauna, while Ctenopharyngodon idella have caused heavy losses in cultures of Cyprinus carpio.