Upstream expansion of round goby (

The round goby Neogobius melanostomus (Pallas, 1814) is one of the most problematic invasive fish species in recent years in Europe. It has proliferated from its native Ponto-Caspian region to several European river systems including their mouths and coastal brackish waters and was also introduced to and became widely established in the Great Lakes in North America. Despite recent reports about further invasions of round goby in the Odra and Vistula Rivers, including penetration of Baltic and North Seas, in the Elbe River this species was only recorded near its mouth close to Hamburg. Here we report the occurrence of round goby 622 km upstream from the previous record in Geesthacht (Germany) in the upper part of the Elbe River in Usti nad Labem (Czech Republic). This report illustrates the fast spread of round goby through several possible pathways, but the most certain is an introduction in ballast water.