Unexpected species richness in the African pike Hepsetus odoe (Bloch, 1794) (Characiformes: Hepsetidae)
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The widespread African pike, Hepsetus odoe (Bloch, 1794), is a member of the monogeneric and, until recently, monospecific family Hepsetidae. Although in the past one additional nominal species and two subspecies have been described, these were all formally synonymized with H. odoe by Roberts (1984). This act, apparently, found general acceptance without any further reservation. Based on a detailed morphometric study including 36 measurements and 18 counts on approximately 450 preserved specimens, a complete revision of the genus Hepsetus was undertaken. This study revealed that Hepsetus contains six well-delineated, valid and mainly allopatric species instead of one: Hepsetus odoe (Bloch, 1794) occurring in the westernmost part of West Africa; H akawo Decru et al., 2012 occurring in the eastern part of West Africa and the northern part of Lower Guinea; H. lineata (Pellegrin, 1926) occurring in Lower Guinea and some adjacent parts of the Congo basin; H. kingsleyae Vreven et al., 2013, endemic to the Ogowe basin in Gabon; H. microlepis (Boulenger, 1901) occurring in the Congo and Chari basin; and H. cuvieri (Castelnau, 1861) in the south up to the Okavango. A mtDNA study (COI) confirmed the morphological results, revealing high levels of interspecific divergence, with high bootstrap support. Furthermore, there are indications that the haplotype distribution within certain species (e.g. H. lineata) is geographically related. Hepsetus odoe, the H. akawo/kingsleyae group and H. lineata appear to have diverged in quick succession followed more recently by the divergence of H. microlepis and H. cuvieri and most recently between H. akawo and H. kingsleyae. These divergences are putatively linked to important geo-climatological events; an attempt is made to use calibration points to estimate the date of these different clade divergences.
CitationDecru, E.; Vreven, E.; De Gelas, K.; Verheyen, E.; Snoeks, J. (2013). Unexpected species richness in the African pike Hepsetus odoe (Bloch, 1794) (Characiformes: Hepsetidae). , The Fifth International Conference of the Pan African Fish and Fisheries Association,