Distribution and diversity of fishes and lampreys in Transylvania (Romania): a complete survey and suggestions for new protected areas

Freshwater fishes are in a serious state of decline across the world, making them one most threatened groups vertebrates. The Danube River catchment area Europe holds richest freshwater fish community, but our knowledge current distribution these species is limited. Transylvania, largest region Romania, important tributaries Danube, from where 77 and two lamprey were recorded until now. Despite this large diversity fishes, there lack systematic survey fauna for past 50 years. In study, we present data on occurrence lampreys collected Transylvania 2007 to 2022. This covers 43% Romania’s surface includes all major rivers Transylvania. 65 three recorded, an additional nine also reported based information competent people. Of 19 (24.7%) non-native, although their relative abundance was low (5.1%) compared other similar regions Europe. first records Eudontomyzon mariae , Neogobius melanostomus Piaractus brachypomus Pygocentrus nattereri Salvelinus alpinus Transylvanian presented, as well record Cobitis elongata outside Nera basin (from Caraș River) detection new populations vulnerable Umbra krameri . Data changes that have occurred since last comprehensive years ago provided importance results conservation planning discussed, including designation protected areas bodies compilation Romanian Red List fishes.