How did subterranean amphipods cross the Adriatic Sea? Phylogenetic evidence for the dispersal-vicariance interplay mediated by marine regression-transgression cycles

Aim: We tested the hypothesis that historical marine regression-transgression cycles shaped the distribution patterns of subterranean amphipods through repeated cycles of dispersal and vicariance against the hypothesis that subterranean amphipods colonized both sides of the Adriatic Sea independently.

Location: Western Balkan Peninsula, Adriatic Sea Islands and Apennine Peninsula, Europe

Taxon: A clade of freshwater subterranean amphipods, genus Niphargus (Crustacea: Amphipoda).

Methods: The taxonomic structure of the studied clade was revised using unilocus species delimitations. Timeframe of cladogenetic events was inferred using multilocus time-calibrated phylogeny and compared to the main regression-transgression events in Miocene and Pleistocene. The geographic origin of the studied clade, species’ range expansions and contractions, as well as vicariant events were assessed through modelling of historical biogeography.

Results: Subterranean amphipods of the genus Nipha...