The European spring snail genus Marstoniopsis (Gastropoda: Amnicolidae): Eastward extension likely driven by Pleistocene glaciations

Abstract

ABSTRACT Although the historical and modern distributional range of the European spring snail genus Marstoniopsis has already been considered in the context of Pleistocene/Holocene glaciations, many details of the eastern limits of these taxa remain uncertain. Also, the taxonomic status of some nominal species commonly attributed to this genus needs to be clarified. In the present study, a literature review of Marstoniopsis and the addition of newly found populations and fossils allow a reconstruction of the geographical and population history of this genus. Results indicate that the majority of the range of Marstoniopsis is inhabited by M. insubrica (Küster, 1853), though several local endemic taxa probably represent distinct species: M. armoricana (Paladilhe, 1869), M. croatica Schütt, 1974, M. vrbasi Bole et Velkovrh, 1987 and M. graeca (Radoman, 1978). The populations in the middle parts of the Dnieper and Volga rivers mark the south-eastern limit of the distribution of Marstoniopsis. Localities along with the eastern distribution limit of the range in European Russia and Ukraine mostly conform to the configuration of the zone of maximal (Riss-Saale-Dnieper) glaciation. Fossil records from Hungary and Slovakia show that Marstoniopsis inhabited central Europe (where these snails are now absent) at least during the early Holocene. It is here suggested that during the whole Pleistocene and Holocene the historical range of Marstoniopsis pulsated in accordance with the area size occupied by the glaciations. The overall geographic range of these snails includes the basins of rivers flowing into the North, Baltic, Black and Caspian seas. Isolated occurrences in Europe are mainly in closed lakes in mountainous areas of the Alps and the Balkans and are considered as refugia in the southern side of the Alps.