Across Siberia and over Europe: Phylogenetic relationships of the freshwater fish genus Rhodeus in Europe and the phylogenetic position of R. sericeus from the River Amur.

We present the phylogenetic relationships of the freshwater fish genus Rhodeus from 45 localities in Europe and three localities in the Amur basin using the mitochondrial cytochrome b sequence. The study aims to (1) test the colonisation history between Europe and East Asia and (2) to reconstruct the evolutionary history of Rhodeus in Europe. Our analyses revealed five monophyletic clades which correspond to four species: R. sericeus in the Amur basin, R. meridionalis in the River Vardar, R. colchicus in western Caucasus and two sister lineages in most of Europe which together represent R. amarus. The reconstructed colonisation scenario assumes a continuous distribution of Rhodeus from Europe through Siberia until East Asia during Pliocene, depletion of the Siberian population in late Pliocene, isolation of the population in River Vardar during early Pleistocene, refuges during late Pleistocene glaciations in the Danubian basin, in the lowlands of western Black Sea and in western Caucasus Mountains and a post-glacial expansion from the Danubian refuge towards western Europe and from the Black Sea refuge across Eastern Europe.