Recent radiation of Iberian barbel fish (Teleostei, Cyprinidae) inferred from cytochrome b genes.

Nucleotide sequence fragments of the mitochondrial DNA gene encoding cytochrome b were examined in 26 individuals belonging to the seven species of Barbus endemic to the Iberian Peninsula: Barbus haasi, B. bocagei, B. graellsii, B. sclateri, B. comiza, B. guiraonis, and B. microcephalus. Six of the seven currently recognized species can be distinguished on the basis of their cytochrome b nucleotide sequences. Sequence divergence estimates for Spanish species of Barbus (0-6.5%) are, in general, low in comparison to those reported for other fish species, and hybrid individuals were found. All of these observations suggest a recent radiation. The inferred phylogenetic tree has two main clades, one including B. graellsii, B. guiraonis, and B. microcephalus, and the other the remaining species groups.