Extensive intergeneric hybridisation in the large cyprinids from the Inkisi River basin (Lower Congo, DRC): a unique case or a possible widespread pan-African phenomenon?
Wamuini Lunkayilakio, S.
MetadataShow full item record
A detailed morphometric, meristic and genetic study of 36 specimens of the large-size cyprinids with high lateral line scale numbers (i.e. 36 or more) from the Inkisi basin, revealed that only a few can readily be identified as belonging to Varicorhinus or Labeobarbus as based on diagnostic mouth shapes; however, the remaining specimens, exhibit intermediate and variable mouth-shape phenotypes. Mitochondrial COI haplotypes did not enable differentiation between V., L. and intermediate phenotypes, but AFLP multilocus nDNA analyses strongly suggest that both, the V.- and L.- phenotypes, represent two identifiable lineages whereas the intermediates are most parsimoniously interpreted as a polymorphic V. x L. hybrid swarm. Although reports of possible L. x V. hybridisation are not new [Banister, 1972; 1973 (V. tanganicae: now Acapoeta); De Vos & Thys van den Audenaerde, 1990], the major difference with the above mentioned cases is that in the Inkisi River both yet undescribed parental species are, except for their mouth-shape phenotype, hardly distinguishable by meristics as well as mouth-morphotype-independent morphometrics. The implications seem far reaching. Though currently 37 valid Varicorhinus species are known, six of these species lack the typical cutting-edge on the lower jaw rendering them more similar to some of the Inkisi intermediate phenotypes. Further, eight of the 92 African valid Labeobarbus species have one or several Varicorhinus junior synonyms. In view of the current evidence, a high degree of intraspecific polymorphism seems less likely for these cases than a repeated case of intensive intergeneric hybridisation, which we hypothesize may be the rule rather than the exception. The results presented here might also shed new light on the Lake Tana L. intermedius shore complex - one of those L. species with a V. synonym. Including Varicorhinus in a review, is therefore critical to enhance our current understanding of the rapid Labeobarbus speciation in that lake.
CitationVreven, E.; Wamuini Lunkayilakio, S.; Musschoot, T.; Obiero, K.; Decru, E.; Snoeks, J.; Schliewen, U.K. (2013). Extensive intergeneric hybridisation in the large cyprinids from the Inkisi River basin (Lower Congo, DRC): a unique case or a possible widespread pan-African phenomenon?. , Fifth International Conference of the Pan African Fish and Fisheries Association (PAFFA5),