Reduced host-specificity in a parasite infecting non-littoral Lake Tanganyika cichlids evidenced by intraspecific morphological and genetic diversity

0468863 - ÚBO 2017 RIV GB eng J - Journal Article
Kmentová, N. - Gelnar, M. - Mendlová, M. - Van Steenberge, M. - Koblmüller, Stephan - Vanhove, M. P. M.
Reduced host-specificity in a parasite infecting non-littoral Lake Tanganyika cichlids evidenced by intraspecific morphological and genetic diversity.
Scientific Reports. Roč. 6, č. 39605 (2016), č. článku 39605. ISSN 2045-2322. E-ISSN 2045-2322
R&D Projects: GA ČR(CZ) GBP505/12/G112
Institutional support: RVO:68081766
Keywords : Monogenean parasites * Ancyrocephalidae * adaptive radiation * statistical tests * population growth * DNA polymorphism * fish families * Teleostei * phylogeny
Subject RIV: EG - Zoology
Impact factor: 4.259, year: 2016

Lake Tanganyika is well-known for its high species-richness and rapid radiation processes. Its assemblage of cichlid fishes recently gained momentum as a framework to study parasite ecology and evolution. It offers a rare chance to investigate the influence of a deepwater lifestyle in a freshwater fish-parasite system. Our study represents the first investigation of parasite intraspecific genetic structure related to host specificity in the lake. It focused on the monogenean flatworm Cichlidogyrus casuarinus infecting deepwater cichlids belonging to Bathybates and Hemibates. Morphological examination of C. casuarinus had previously suggested a broad host range, while the lake's other Cichlidogyrus species are usually host specific. However, ongoing speciation or cryptic diversity could not be excluded. To distinguish between these hypotheses, we analysed intraspecific diversity of C. casuarinus. Monogeneans from nearly all representatives of the host genera were examined using morphometrics, geomorphometrics and genetics. We confirmed the low host-specificity of C. casuarinus based on morphology and nuclear DNA. Yet, intraspecific variation of sclerotized structures was observed. Nevertheless, the highly variable mitochondrial DNA indicated recent population expansion, but no ongoing parasite speciation, confirming, for the first time in freshwater, reduced parasite host specificity in the deepwater realm, probably an adaptation to low host availability.
Permanent Link: http://hdl.handle.net/11104/0266695