Toward the conservation of the endemic monotypic fish genus Aulopyge from the Balkan Dinaric karst: Integrative assessment of introduced and natural population

The complex biogeographical history of the Balkan Peninsula caused remarkable freshwater fish diversity and endemism, among which Cyprinidae fish dominate. The Dinaric karst was a Pleistocene refugium and it harbors ancient and endemic cyprinids, including Aulopyge huegelii, a sole representative of its genus. Being highly distributionally restricted, it faces various threats that promote a critical decline in population abundance and even population extinction. Phenotypic and molecular diversity of the introduced (Šator Lake, Šator Mountain) and natural (Studena River, Duvanjsko Polje) populations of Dalmatian barbelgudgeon from Bosnia and Herzegovina was studied by using two mitochondrial genes and morphometric traits (linear and geometric morphometrics). Nonparametric ANOVA showed that two analyzed populations significantly differed in six linear measurements, except snout length and postorbital head length. Contrary to centroid size, two populations were found to be significantly different in body shape. Deformation grids indicated that individuals from Studena River are characterized by wider and slightly shorter body comparing to individuals from Šator Lake. Incongruence in cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b) mitochondrial DNA (mtDNA) variation was observed since a common COI haplotype was observed, while four and three cyt b haplotypes were registered in Šator Lake and Studena River, respectively. Since it was demonstrated that cyt b mtDNA was a faster evolving gene, we encourage its use in intraspecies studies, especially for evaluating the connectivity of fragmented populations and for studying the evolutionary footprint of the processes incorporated into the distinctive evolution of Aulopyge. Finally, findings herewith provide a firm basis for designing a long-term sustainable conservation strategy for endemic species in Dinaric karst.