Taxonomic and biogeographic analysis of the Proasellus coxalis-group (crustacea, isopoda, asellidae) in Sicily, with description of Proasellus montalentii n. sp.

Abstract

The genus Proasellus is widespread in ponds, ditches and rivers of Sicily. A detailed morphological analysis of several samples of asellids collected in Sicilian freshwaters resulted in the determination of three species of the Proasellus coxalis-group: P. banyulensis italicus (Dudich, 1925), P. montalentii n. sp. and P. wolfi (Dudich, 1925), which is elevated to specific rank. The three species can be distinguished on the basis of the sutures of pleopod V. exopod. Proasellus montalentii inhabits the western part of Sicily, while the range of P. wolfi is confined to the Iblean region. Both species are more closely related to the North African taxa of Proasellus coxalis-group, while Proasellus banyulensis italicus is very similar to the populations found in peninsular Italy. These patterns are explained supposing multiple colonizations of Sicily during Pliocene connections.