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, also monospecific family Hepsetidae. Altough in the past one additional nominal species and two subspecies have been described, these were all formally synoymized with H. odoe by Roberts (1984). This act apparently has found general acceptance without any further reservation. Based on a detailed morphometric study including 36 measurements and 18 counts on about 450 preserved specimens, a complete revision of the genus Hepsetus was undertaken. This study revealed that Hepsetus contains six well delineated, valid species instead of one. Recently, the southern African H. cuvieri (Castelnau, 1861), was rehabilitated (Zengeya et al., 2011). The junior synonyms H. odoe lineata and H. odoe microlepis were found to represent valid species with H. lineata occuring in Lower Guinea and some adjacent parts of the Congo basin. Furthermore, two new species were discoverd: one recently described as Hepsetus akawo (Decru et al., 2012)from the eastern part of West Africa and the northern part of Lower Guinea; and the other Hepsetus sp. 'kingsleyae', a species endemic to the Ogowe basin in Gabon which is currently under description. Hepsetus odoe is now restricted to the westernmost part of West Africa. Interestingly, while Hepsetus species mostly have allopatric distributions, in the Ogowe basin both H. lineata and H.sp.'kingsleyae' were found sympatrically and even syntopically, the former mainly occurring in the main stream, while the latter seems to prefer the associated lakes. Preliminary genetic results (COI-bar coding) appear to confirm the morphological results.
CitationDecru, E.; Vreven, E.; Snoeks, J. (2012). Unexpected species richness in the African pike Hepsetus odoe (Bloch, 1794) (Characiformes: Hepsetidae). , XIV European Congress of Ichthyology Liège, 3-8 July 2012 (Belgium),