Publication details
Genetic and morphological variability of tapeworm Khawia armeniaca (Cholodkovski, 1915) (Cestoda: Caryophyllidea)
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| Year of publication | 2024 |
| Type | Conference abstract |
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| Description | Caryophyllidean tapeworm Khawia armeniaca, parasite of freshwater fishes of the family Cyprinidae, has been reported from various countries in Africa, Asia and Europe since its initial description in 1915. This tapeworm was originally assumed to represent a species with the widest host spectrum among all the other congeneric species, along with the broadest geographical distribution spanning two zoogeographical regions (i.e., the Palearctic and Ethiopian). However, a recent taxonomical revision of the genus Khawia revealed significant intraspecific variability within K. armeniaca, which led to an assumption that it might actually constitute a complex of species. Our study aimed to investigate this diversity by analyzing samples extracted from 13 cyprinid and 1 mastacembelid species in the Middle East, Northern Africa and the Iberian Peninsula, using both molecular and morphological approach. To assess the molecular diversity of K. armeniaca, partial 18S rDNA, 28S rDNA, and ITS2 region were sequenced. The conducted phylogenetic analysis divided all investigated individuals into two distinct lineages, which clearly corresponded to their geographical origin and decisively separated tapeworms from the Iberian Peninsula and the Middle East. The tapeworms of the first lineage from Arabibarbus grypus, Barbus lacerta, Carassobarbus luteus, Luciobarbus barbulus, L. esocinus, and L. kersin in Iraq and Iran are genetically identical to Khawia armeniaca, which was described from the Sevan khramulya Capoeta sevangi in Armenia. Tapeworms of the other lineage are found in Luciobarbus bocagei, L. comizo, and L. guiraonis from Portugal and Spain. Furthermore, morphological analyses on a total of 40 morphometric characters revealed that the tapeworms of both lineages mainly differ from each other in shape, structure and size of the ovary and the anterior extent of the vitelline follicles. Upon comprehensive evaluation of both molecular and morphological distinctions, our findings lead us to assert that the tapeworms from the Iberian Peninsula should be regarded as a distinct species. Given the limited amount of material suitable for molecular analysis, more sampling within the Northern Africa region should be conducted to fill the genetic-data gap, which could illuminate the phylogenetic relationships among Khawia spp., associated with the fish hosts and their presumed dispersion into the Iberian Peninsula. Acknowledgements: This study was financially supported by project VEGA 1/0583/22. |