Evidence of a cenozoic Betic-Kabilian connection based on freshwater fish phylogeography (Luciobarbus, Cyprinidae)

The phylogenetic relationships among 26 species of the subgenus Luciobarbus were examined through comparison of the complete sequence of the mitochondrial genes ATPase 6 and 8 and cytochrome b. The monophyletic condition of the Luciobarbus subgenus was confirmed by several data treatment methods. Findings indicate a closer relationship among species inhabiting Caucasian, Greek, and North African areas than between the latter and those of the Iberian region. The isolation of these main clades is postulated to have occurred after the Messinian salinity crisis (5.5 MY ago) when the Iberian Peninsula broke away from the African continent. Based on a calibrated molecular clock proposed herein, the subsequent splitting of this subgenus corresponds to the isolation of the other three areas (Caucasian, Greek, and North African) about 4.5 MY ago, which would have interrupted any possible gene flow between lineages. However, the present data indicate that the North African Kabilies Mountain area maintained its contact with the south Iberian Peninsula for a longer period.