Abstract: | The species of the genus Labeo from the Lower Zaire river system have been revised on the basis of 284 preserved fishes, including type material of 18 nominal species cited or described from this region. Morphometrics, meristic counts, morphological observations and radiographs have been used for this study. All results obtained are supported by statistical analyses. From the 18 nominal species reported, only 12 species are recognized as valid. Two major groups were identified: one group has rows of conical papillae on the inner surface of lips; and the other group presents rows of transverse plicae on the inner surface of lips. The first group has two species: L. lineatus and L. weeksii. One synonymy is proposed: L. lineatus (partim) = L. weeksii. In the second group, 10 species have been identified: L. longipinnis, L. degeni, L. barbatus, L. macrostoma, L. falcipinnis, L. cyclorhynchus, L. parvus, L. greenii, L. nasus and L. sorex. One unidentified taxon apparently represents a species new to science, but this must be confirmed by a wider revision of the genus which is the subject of further research. Some synonymies in this group are proposed: L. brichardi (partim) = L. barbatus; L. lineatus (partim) = L. degeni. Other synonymies already established by Reid (1985), have been confirmed: L. lividus = L. barbatus; L. brichardi (partim) = L. macrostoma; L. variegatus = L. cyclorhynchus. One synonymy has been restored: L. velifer = L. longipinnis. Finally, one synonymy remains in question: L. chariensis = L. parvus. A key to species is provided. |