Monogenean parasites of pelagic fish species in Lake Tanganyika: potential tags for host history and population structure
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| Year of publication | 2019 |
| Type | Conference abstract |
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| Description | Lake Tanganyika is the oldest and deepest of the African Great Lakes and harbours one of the most diverse fish assemblages on earth. Of the entire fisheries concentrated mainly in the lake’s pelagic zone, two species of sardines (Limnothrissa miodon and Stolothrissa tanganicae) constitute the majority within the total of catches. To provide an additional view of their lake-wide population structure, we examined the monogenean parasites (Platyhelminthes) of the abovementioned species in order to explore the parasites’ potential as tags for their hosts’ population structure or history. Samples originated from several localities including all three subbasins of the lake. Intraspecific morphological variation was analysed using morphometrics and geomorphometrics of the monogeneans’ sclerotised structures. Molecular characterisation was conducted using a range of nuclear and mitochondrial markers. Our results indicate a lake-wide distribution of two monogenean species assigned to a new genus, Kapentagyrus, infecting Lake Tanganyika’s sardines. Unlike Cichlidogyrus casuarinus, a monogenean reported from members of the pelagic cichlid tribe Bathybatini with no host preference, K. tanganicanus includes two morphotypes specific to the respective sardine species. Moreover, incipient speciation related to host species identity was reported in K. tanganicanus. Based on our molecular markers, we find a near panmictic population of Kapentagyrus spp. with an indication of restricted gene flow on a lake-wide scale. Morphometric and shape variation data of both parasite species revealed significant differences in some of the parameters, potentially an indication of limited host migration. Moreover, both parasites species underwent recent demographic expansion that can be linked to paleogeographic events |
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