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Within the genus Hepsetus, a new species from the eastern part of West Africa is described. Hepsetus akawo sp. nov. is mainly distinguished from Hepsetus odoe by a smaller number of lateral line scales [43–51 vs 50–60 (exceptionally 49)] and a shallower head depth [38.0–45.6 (mean 42.0) % head length vs 41.4–49.0 (44.6) % head length] (positively allometric). Hepsetus akawo sp. nov. differs mainly from the recently rehabilitated Hepsetus cuvieri by: a higher number of gill rakers (17–23 vs 8–13); and a lower number of scales between the dorsal fin and the lateral line (7½–9½ vs 10½–11½). Within West Africa, the distribution area of the new species is restricted to the Sassandra River (Ivory Coast) in the west up to the Cross River (Cameroon) in the east. The species is entirely allopatric with H. odoe, which has a far more restricted distribution than previously thought and occurs from the Senegal River (Senegal) in the west to the Cavally River (Ivory Coast) in the east. [ABSTRACT FROM AUTHOR]

Hepsetus cuvieri (Castelnau, 1861), originally described from 'lac N'gami' (Botswana) and synonymized with H. odoe (Bloch, 1794) by Roberts (1984), is revalidated. Hepsetus cuvieri can be readily distinguished from H. odoe based on a lower total number of gill rakers (8-13 versus 14-21); a generally higher number of scales between the dorsal fin and the lateral line (10½-11½ versus 7½-10½) and a higher number of scales between the adipose fin and the lateral line (6½-7½ versus 4½-6½) and other characters. A neotype is designated, as the holotype of this nominal species is apparently lost. Hepsetus cuvieri is restricted to the Quanza, Zambezi ichthyofaunal provinces and the southern part of the Congo Basin, i.e. the Congo ichthyofaunal province. [ABSTRACT FROM AUTHOR]

A detailed morphometric study was undertaken of collections of the Lake Tanganyika endemic Mastacembelus ophidium. On each specimen 27 measurements and 12 meristics were taken. Within the specimens previously identified as M. ophidium a new species was discovered. A redescription of M. ophidium and a description of the new species are provided. [ABSTRACT FROM AUTHOR]

The family Mastacembelidae is currently divided into two subfamilies, the Mastacembelidae and the Afromastacembelinae. Within the African Afromastacembelinae two genera, Caecomasiacembelus and Aethiomastacembelus, are recognized. Both the subfamily and the African generic division were critically evaluated mainly through X-ray analyses and osteological research. There is no supporting evidence for a split into two subfamilies. In addition, the present diagnosis of the African genera proved to be unworkable, and no convincing phylogenetic evidence supporting this classification is available. Therefore, pending new detailed phylogenetic research, the use of a subfamily classification within the family Mastacembelidae is not recommended. Furthermore, Caecomastacembelus and Afromastacembelus are placed in synonymy with the genus Masiacembelus. [ABSTRACT FROM AUTHOR]