Fish fauna of the Upper Tisa

Between the headwaters of River Tisa in Ukraine and the city of Tokaj in Hungary1 , the reacher of which, including all backwaters, are named "Upper Tisa", 64 fish species are found. Although 10 species are adventives, their competition is not significant as regards the native fauna. There are valuable characteristics of these reaches, which are related to welldefined ecological zonations, and there are four species endemic to the Danube Basin, one of which currently lives only in River Tisa catchment and River Timi§ in nearby Romania. It is due to the relatively clean water and the variability of habitats that we find a diverse fish fauna. The Upper Tisa runs free of dams and other considerable human impacts, which contribute to the survival of the zonations and natural assets, which are now unique in Europe. The conservation of these natural assets is of common interest to four countries Ukraine, Romania, Slovakia and Hungary