Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

First record of Dikerogammarus bispinosus Martynov, 1925 in Kazakhstan: invasive or overlooked native in the Caspian Sea basin?

Abstract

The Ponto-Caspian amphipod Dikerogammarus bispinosus is regarded as a native species throughout the lower stretches of rivers that drain into the Black Sea. Its occurrence in the Caspian Sea basin was uncertain due to conflicting reports. Here, we provide the first conclusive evidence for its presence in this basin. Individuals of both sexes, including ovigerous females, were collected in May 2000 from the Ural River in Kazakhstan, suggesting full establishment. If it was a recent invasion, the most probable dispersal pathway into the Caspian basin would have been via the Volga-Don canal as D. bispinosus was reported in the early 2000s from the lower Don River and the Saratov reservoir on the Volga River. However, given that until relatively recently D. bispinosus was considered a subspecies of D. villosus, we cannot rule out that it has been overlooked in earlier reports from the Caspian Sea basin by being mentioned as D. villosus or even D. haemobaphes. We also provide new data on the distribution of Gammarus lacustris, Obesogammarus platycheir, Pontogammarus abbreviatus, P. robustoides, Turcogammarus aralensis and Wolgagammarus dzjubani in western Kazakhstan and southwestern Russia.