The aquarium pet trade as a source of potentially invasive crayfish species in Serbia.

The aquarium pet trade is a source of potentially invasive crayfish species, which can be subsequently intentionally or unintentionally introduced into new environments. This can lead to biological invasions that represent a threat to native biodiversity and, in particular, freshwater ecosystem functioning. In global terms, Europe is the most affected region, and invasive crayfish species are increasing in number, establishing their populations and expanding their ranges. Despite being similarly affected, the situation in Serbia (SE Europe) has remained overlooked in this regard. A survey of the aquarium pet trade in this country revealed six different crayfish species traded as ornamentals. Marbled crayfish Procambarus virginalisLyko, 2017, a well-known invader, was traded in more than half of the studied towns and cities in Serbia and is commonly available both in pet shops and through e-commerce (online selling). Other potentially invasive crayfish include the red swamp crayfish Procambarus clarkii (Girard, 1852) and the Florida crayfish Procambarus alleni (Faxon, 1884), both of which are already established in some European inland waters. The presence of invasive species in the aquarium pet trade in Serbia could theoretically lead to their occurrence in the wild. Given that, in terms of cost and feasibility, the best defence against biological invasions is prevention. A rapid response to the findings discussed here could be the key to prevent future invasions of Serbian freshwater ecosystems by non-native crayfish species. [ABSTRACT FROM AUTHOR]