Diagnosis: last simple dorsal ray ossified and as long as or shorter than head in specimens over 150 mm SL; lips normally well developed, with or without mental lobe; mental lobe absent in certain populations from Liberia; 8-9 dorsal fin branched rays; scale formula 3.5-5.5/24-31/4.5; 2 scales between lateral line and pelvic-fin base; 12 scales around caudal peduncle; 2-4/10-14 gill rakers on first gill arch (Ref. 2940, 81282).

Description: polymorphic species; body moderately deep; lips poorly developed in Liberian populations, mental lobe in many individuals from Guinea; 2 well developed barbels, variable in length among water basins; dorsal fin short, last simple dorsal-fin ray not exceeding head length, ossified at base, with ossified part forming a spine always shorter than head; distal margin dorsal fin more or less straight, sometimes slightly concave; D:IV,9; A:III,5; P:14-16; V:I,8 or 9 (Ref. 2940, 81282).

Coloration: ground color yellowish-green, belly lighter and fins yellow (Ref. 2940, 81282).