An overlooked invader: Cryptorchestia garbinii (Amphipoda: Talitridae) colonizing Serbian banks of the Danube

Abstract

Abstract The talitrid Cryptorchestia garbinii is a terrestrial and riparian European amphipod, distributed throughout the continent and well-known as a recent invader of the shores and banks of many water bodies. In the last decades, the species significantly expanded its range in the Balkans. First records of this species in Serbia are presented here and include descriptions of the habitats. The species was found at several localities alongside the Danube at the Iron Gates. The species was first observed in the Serbian section of the river in 2017. Abundance at this time was very high indicating that colonization almost certainly occurred much earlier. We discuss possible reasons why the species was not detected in Serbia before, as well as probable ways of its arrival and spread. Even though C. garbinii is the eighth allochthonous amphipod detected in Serbia, it is the first semiterrestrial representative, and also, the first one from the infraorder Talitrida recorded in the country.