Mitochondrial DNA suggests uniqueness of an isolated population of the Italian minnow (Phoxinus lumaireul Schinz, 1840) (Teleostei: Cyprinidae) in central Apennines (Italy)

Two mitochondrial genes (cytochrome oxidase I and cytochrome b) were examined to compare an isolated population of the Italian minnow in the central Apennines to other populations in the species' range (Po plain) and other European minnow species. Both mitochondrial markers showed a new haplotype, fixed in a sample of 30 specimens, never observed in the main species distribution range, and ostensibly divergent from other Italian minnow haplotypes. The result suggests a long history of isolation, probably preceding the Holocene retreat northwards of the Po River. This relict population is now at serious extinction risk owing to habitat loss and predation by alien trout restocked into the wild for recreational fishing purposes.