Alpine and Apennine barriers determining the differentiation of the rudd (Scardinius erythrophthalmus L.) in the Italian peninsula

A phylogeographic study of rudd Scardinius erythrophthalmus L. (Pisces: cyprinidae) was addressed to determine the differentiation of Italian populations in relation to the presence of mountain barriers, which identify two biogeographic districts (Padano-Venetian, Tuscano-Latium). At this scope, 409 bp long sequences of mtDNa cytochrome b gene were obtained from Italian and central European samples. Italian rudds phylogeny showed low level of divergence which although resulted from the central European haplotypes. The genetic structure of haplotypes in the studied districts revealed a significant recent fragmentation event. The Padano-Venetian populations showed patterns of past range expansion caused by the specie dispersion by river connections occurred during Pleistocene. This pattern provides evidence for (i) the role of Alps as a barrier for rudd dispersion; (ii) a significant genetic structure among the studied districts related to recent isolation events by the Apennine barrier; (iii) the role of Pleistocene sea level variations in determining phylogeography of the Padano-Venetian populations.