A re-evaluation of species diversity within the Labeo (Cypriniformes: Cyprinidae) with papillary lips from the Congo basin
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The taxonomy of the African representatives of the paleotropic genus Labeo is confusing and difficult. Indeed, in spite of the revisions conducted by Reid (1985) and Tshibwabwa (1997), taxonomical inconsistencies are still encountered and hamper the correct identification of species. This study focuses on the Labeo Cuvier 1816 species with papillary lips from the Congo basin. Currently five species are reported from this basin: L. altivelis Peters 1852, L. mesops Günther 1868, L. lineatus Boulenger 1898, L. weeksii Boulenger 1909 and L. maleboensis Tshibwabwa 1997. One hundred and eighty-eight specimens, including all types, were studied using 16 counts and 22 measurements. The results indicate that only two species, L. altivelis and L. lineatus, remain valid. Labeo altivelis is widespread across the Congo basin and also found in the Zambezi and in neighbouring eastward-flowing rivers; L. lineatus is a widespread Congo endemic, but absent in the Tanganyika basin. These morphometric results were confirmed by a preliminary DNA (COI) barcoding study. As dorsal fin shape has often been identified as one of the principal criteria to discriminate between Labeo species, special attention was given to this character. This revealed that intra- as well as inter-specific differences in allometric growth shape the differences observed both in size and contour of the dorsal fin. In L. lineatus, the dorsal fin remains small and with a straight edge in all sizes and regardless of the geographical origin of the specimens. However, in L. altivelis, the dorsal fin becomes larger with increasing size and different populations have a differently shaped dorsal fin edge: concave for specimens from the Lower and Central Congo, and convex for those of the Zambian Congo. The occurrence of L. rosae Steindachner 1894, in the Lufira (Upper Congo), reported here for the first time, is most likely the result of an introduction.
CitationGajdzik, L.; Van Steenberge, M.; Chilala, A.; Snoeks, J.; Vreven, E. (2013). A re-evaluation of species diversity within the Labeo (Cypriniformes: Cyprinidae) with papillary lips from the Congo basin. , Fifth International Conference of the Pan African Fish and Fisheries Association (PAFFA5),