Diversity of alien macroinvertebrate species in Serbian waters.
This article provides the first comprehensive list of alien macroinvertebrate species registered and/or established in aquatic ecosystems in Serbia as a potential threat to native biodiversity. The list comprised field investigations, articles, grey literature, and unpublished data. Twenty-nine species of macroinvertebrates have been recorded since 1942, with a domination of the Ponto-Caspian faunistic elements. The majority of recorded species have broad distribution and are naturalized in the waters of Serbia, while occasional or single findings of seven taxa indicate that these species have failed to form populations. Presented results clearly show that the Danube is the main corridor for the introduction and spread of non-native species into Serbia.