A morphological revision of the Brycinus macrolepidotus (Valenciennes, 1850) group (Characiformes: Alestidae) reveals unexpected species diversity
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The genus Brycinus includes, morphologically, three species groups, i.e. the longipinnis, nurse and macrolepidotus group (Paugy, 1986). However, only the monophyly of the latter, including eight valid species so far, has genetically been confirmed (see Hubert et al., 2005). Although important studies have been undertaken, the status of some of the included species still remains unsettled. For instance, the Congo B. carmesinus is still known from the holotype only and the Lower Guinea B. schoutedeni and B. batesii have recently been considered junior synonyms of B. macrolepidotus by Paugy (2007). Five meristics and 27 morphometric characters have been studied on a total of 294 specimens of the macrolepidotus group originating from all over its distribution area. The results allow the meristic recognition of two species groups based on the number of anal branched rays (mode 11-13 vs. 12-14) and the number of outer premaxillary teeth (mode 8 vs. 10). The first group is referred to as the macrolepidotus group sensu stricto and includes B. brevis, B. macrolepidotus, B. rhodopleura, and a first group of specimens identified as a new species for science, B. sp. congo , while the second species group, referred to as the grandisquamis group, includes B. batesii, B. carmesinus, B. grandisquamis, B. poptae, B. schoutedeni and a second group of yet unidentified Congo basin specimens. Further analysis of the macrolepidotus group so far revealed that the specimens from the Congo basin, previously attributed to widely distributed B. macrolepidotus, in fact belong to a Congo endemic undescribed species, B. sp. congo . Indeed, B. sp. congo can be distinguished from B. macrolepidotus by, next to others, the presence of: a single row of outer premaxillary teeth (vs. two) and a single scale between pelvic fin insertion and lateral line (vs. two). Further research on the grandisquamis group is still ongoing.
CitationKoné, T.; Vreven, E. (2013). A morphological revision of the Brycinus macrolepidotus (Valenciennes, 1850) group (Characiformes: Alestidae) reveals unexpected species diversity. , Fifth International Conference of the Pan African Fish and Fisheries Association (PAFFA5),