Approaches using microsatellite markers are considered the gold standard for modern population genetic studies. However, although they have found application in research into various platyhelminth taxa, they remained substantially underutilized in the study of monogeneans. In the present study, a newly developed set of 24 microsatellite markers was used to investigate the genetic diversity of the generalist monogenean species Dactylogyrus vistulae. The analyzed parasite specimens were collected from 13 cyprinoid species from 11 sites in the Apennine and Balkan peninsulas. A total of 159 specimens were genotyped at each of the loci and the number of alleles per locus ranged from 2 to 16, with a mean number of 6.958 alleles per locus. Exceptionally high genetic diversity was observed among D. vistulae individuals in the southern Balkans (mean N A per locus = 3.917), suggesting that generalist D. vistulae expanded from the south to the north in the Balkans and later into central Europe. The initial clustering analysis divided all investigated specimens into three major clusters; however, the results of the subsequent analyses revealed the existence of various subpopulations, suggesting that the population structure of D. vistulae is associated with the diversification of their cyprinoid hosts. In addition, the partition of the parasite population was observed in regions of the sympatric occurrence of two host species, indicating that these hosts may represent a barrier for gene flow, even for generalist parasite species.

• Keywords
• Cyprinoidei, historical dispersion, host‐specific parasites, polymorphic markers, population genetics,
• Publication type
• Journal Article MeSH

Parasites exhibiting a high degree of host specificity are expected to be intimately associated with their hosts. Therefore, the evolution of host-specific parasites is at least partially shaped by the evolutionary history and distribution of such hosts. Gill ectoparasites of Dactylogyrus (Monogenea) are specific to cyprinid fish. In the present study, we investigated the evolutionary history of 47 Dactylogyrus species from the Balkan Peninsula, the Mediteranean region exhibiting the highest cyprinid diversity in Europe, and from central European cyprinids. Phylogenetic analyses revealed four well-supported clades of endemic and non-endemic Dactylogyrus spp. with four basal taxa. Endemic cyprinids with a limited distribution range were parasitized by endemic Dactylogyrus species, but some of them shared several Dactylogyrus species with central European cyprinids. Species delimitation analyses based on molecular data suggest that Dactylogyrus diversity is higher than that defined from morphology. Some endemic cyprinid species harboured Dactylogyrus species of different origins, this probably resulting from multiple host switching. Our results support the view that the evolution of Dactylogyrus in the Balkans has been influenced not only by the historical dispersion and distribution of their cyprinid hosts, but also by recent contacts of non-native cyprinid species with endemic cyprinid fauna in this region.

• MeSH
• Biodiversity * MeSH
• Cyprinidae parasitology   MeSH
• Phylogeny * MeSH
• Host Specificity * MeSH
• Evolution, Molecular MeSH
• Platyhelminths classification   genetics   isolation & purification   MeSH
• Gills parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Balkan Peninsula MeSH
• Mediterranean Region MeSH

BACKGROUND: The host specificity of fish parasites is considered a useful parasite characteristic with respect to understanding the biogeography of their fish hosts. Dactylogyrus Diesing, 1850 (Monogenea) includes common parasites of cyprinids exhibiting different degrees of host specificity, i.e. from strict specialism to generalism. The phylogenetic relationships and historical dispersions of several cyprinid lineages, including Aulopyge huegelii Heckel, 1843, are still unclear. Therefore, the aims of our study were to investigate (i) the Dactylogyrus spp. parasites of A. huegelii, and (ii) the phylogenetic relationships of Dactylogyrus spp. parasitizing A. huegelii as a possible tool for understanding the phylogenetic position of this fish species within the Cyprininae lineage. RESULTS: Two species of Dactylogyrus, D. vastator Nybelin, 1924 and D. omenti n. sp., were collected from 14 specimens of A. huegelii from the Šujica River (Bosnia and Herzegovina). While D. vastator is a typical species parasitizing Carassius spp. and Cyprinus carpio L, D. omenti n. sp. is, according to phylogenetic reconstruction, closely related to Dactylogyrus species infecting European species of Barbus and Luciobarbus. The genetic distance revealed that the sequence for D. vastator from A. huegelii is identical with that for D. vastator from Barbus plebejus Bonaparte, 1839 (Italy) and Carassius gibelio (Bloch, 1782) (Croatia). Dactylogyrus omenti n. sp. was described as a species new to science. CONCLUSIONS: Our findings support the phylogenetic position of A. huegelii within the Cyprininae lineage and suggest that A. huegelii is phylogenetically closely related to Barbus and Luciobarbus species. The morphological similarity between D. omenti n. sp. and Dactylogyrus species of Middle Eastern Barbus suggests historical contact between cyprinid species recently living in allopatry and the possible diversification of A. huegelii from a common ancestor in this area. On other hand, the genetic similarity between D. vastator ex A. huegelii and D. vastator ex C. gibelio collected in Balkan Peninsula suggests that A. huegelii was secondarily parasitized by D. vastator, originating from C. gibelio after introduction of this fish species from Asia to Europe.

• Keywords
• Aulopyge, Coevolution, Cyprininae, Dactylogyrus, Host specificity, Phylogeography,
• MeSH
• Cyprinidae classification   parasitology   MeSH
• Species Specificity MeSH
• Phylogeny MeSH
• Phylogeography MeSH
• Host Specificity * MeSH
• Trematode Infections parasitology   veterinary   MeSH
• Fish Diseases parasitology   MeSH
• Trematoda classification   genetics   isolation & purification   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Asia MeSH
• Bosnia and Herzegovina MeSH
• Croatia MeSH
• Italy MeSH