Parasitofauna of allochthonous fish species in the open waters of the danube river basin (Serbian part) – impact on the native fish fauna

In this review data on parasitofauna of allochthonous fish species in the Danube River Basin in Serbia is presented. Up to now, 33 ecto-and endoparasites of seven examined allochthonous invasive fish species have been reported. Some of the identified parasitic species are new for fish parasitofauna in the Serbian waters (Trichodina nobilis, Balantidium sp., Philometroides cyprini, Philometroides parasiluri, Eustrongylides sp., Ergasilus sieboldi, Lernaea cyprinacea, Sinergasilus polycolpus). In the open waters of Serbia (the Danube River Basin) a total of 26 non-indigenous fish species were recorded, of which 16 were the allochthonous invasive fishes. The major means of introductions and translocations were found to be the aquaculture, fish stocking and transportation. Habitat modification was found to be the factor that largely contributes to the capability of the water bodies to become a suitable recipient area. The large presence of alien fish species (27.66%) and its parasites creates a serious threat to the stability of freshwater ecosystems and the survival of the native ichthyofauna. The main environmental consequences of alien fish spreading are related to the alteration in fish community structure and function, as well as the introduction of the alien parasite species