Non-native species are known to escape their parasites following introduction into a new range, but they also often acquire local parasites as a function of time since establishment. We compared the parasite faunas of five non-native Ponto-Caspian gobies (Gobiidae) and local fish species (Perca fluviatilis, Gymnocephalus cernua, Gobio gobio) in three European river systems; the Rivers Rhine, Vistula and Morava, where Ponto-Caspian gobies were introduced 4-13 years prior to the study. Overall parasite species richness was considerably lower in non-native gobies compared to local fish species, and the same result was found at the component and infra-community levels. Both parasite abundance and diversity greatly varied among the regions, with the highest values found in the River Vistula (Wloclawski Reservoir), compared to a relatively impoverished parasite fauna in the River Morava (Danube basin). While only half of parasite species found in local hosts were acquired by non-native gobies, most of the parasites found in gobies were shared with local fish species related either phylogenetically (percids) or ecologically (benthic gudgeon), including the co-introduced monogenean Gyrodactylus proterorhini. As a result, similarity in parasite communities strongly reflected regional affiliation, while phylogenetic distances between fish host species did not play a significant role in parasite community composition. In accordance with other studies, all parasites acquired by gobies in their new range were generalists, all of them infecting fish at the larval/subadult stage, indicating the possible importance of gobies in the life cycle of euryxenous parasites. The absence of adult generalists, particularly ectoparasites with low host specificity, in non-native fish may reflect their generally low abundance in the environment, while an absence of adult endoparasitic generalists was probably related to other factors.
Introdukce nepůvodních druhů ryb má celosvětově dlouhodobou tradici, ale ne všechny zavlečené druhy jsou schopny v novém prostředí vytvořit stálé populace. Při introdukci organismů do nového prostředí dochází také k zavlečení jejich parazitů. Druhová početnost parazitů však bývá nižší než v původní oblasti hostitele. Severoamerická ryba slunečnice pestrá (Lepomis gibbosus) se v Evropě dokázala rozšířit téměř po celém kontinentu. V průběhu opakovaných introdukcí došlo k zavlečení sedmi druhů žábrohlístů, slunečnice však také v Evropě přejala některé místní parazity. and The introduction of non-native species has a worldwide long-term tradition, but only a few species are able to establish in the new area. Parasites are also frequently introduced together with their hosts. The North American fish Lepomis gibbosus has established itself in almost all European countries. Seven monogenean parasites were transported with the fish host, moreover, L. gibbosus accepted some of the local parasites.