Distribution of the species of Theodoxus Montfort, 1810 (Gastropoda: Neritidae) in Serbia: an Overview

Abstract

The distribution of freshwater snails of the genus Theodoxus in Serbia is examined. The study comprises literature data and field surveys carried out at 84 watercourses and 5 reservoirs during 2010-2013. The occurrence of three species is confirmed: Theodoxus fluviatilis, T. danubialis and T. transversalis. The most widespread species is T. fluviatilis (river nerite). The previously dominant nerite T. danubialis (Danube nerite) currently persists mainly in hilly and mountain parts of central Serbia and remains in few localities only in large rivers such as the Danube and the Sava. The endangered species T. transversalis (striped nerite) shows patchy distribution; the Drina River – Lim River and the Velika Morava River – Južna Morava River – Nišava River systems are revealed as important refugia for this species. Moreover, at some localities at the Nišava River and the Velika Morava River, the striped nerite is found to be the dominant in the present gastropod communities. Regular studies are crucial for the timely prediction of population health and for conservation of freshwater nerite species in Europe.