Parasites of round goby, Neogobius melanostomus, currently invading the Elbe River

The round goby, Neogobius melanostomus, is a Ponto-Caspian fish species currently found in many parts of Europe, including the North Sea riverine deltas. The objective of this study was to examine the parasite community of fish caught in the lower Elbe (Suderelbe - tidal zone; Geesthacht - non-tidal) in Germany and compare it with published data from the upper Elbe (Usti nad Labem) in the Czech Republic. Twelve parasite taxa were recorded in the lower Elbe, six in the Suderelbe and nine near the city of Geesthacht. Suderelbe fish were mainly infected with Angullicola crassus larvae, while gobies from Geesthacht - with glochidia and sporadically occurring Pomporhynchus laevis, and the opposite situation was observed at Usti nad Labem. It appears that a large tidal weir at Geesthacht significantly contributes to the division of the round goby population, with the Geesthacht parasite community being more similar to that at Usti nad Labem than the one from the Suderelbe, thus increasing the likelihood that shipping from Hamburg was the introduction vector to Usti nad Labem. We also recorded Acanthocephalus rhinensis in the Elbe for the first time, and in a new host - the round goby. Thus, round gobies may represent a new vector for the introduction of this parasite along the Elbe.