Marcusenius abadii (Boulenger, 1901)
Species overview
Medium-sized fish, body long-rhomboid in shape, moderately deep, head uneven-blunt-snouted, unpaired fins of about equal length. Silvery with darker back, sometimes with a dark bar between unpaired fins. Size observed: 233 mm SL, 263 mm TL.
M. abadii(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed, moderately deep, body depth 24-33 % SL, greatest depth near origin of unpaired fins.
-Head moderately long and deep, head length about 20-23 % SL, head depth 12-17 % SL, 44-65 % body depth.
-Outline of back slightly convex, upper profile of head convex, underside of head concave, outline of belly slightly curved.
-Snout obtusely pointed, 23-28 % head length, 35-69 % postorbital length.
-Mouth small, terminal, its edge below anterior nostril, upper jaw on a level with lower rim of eye.
-Chin with globular swelling (in museum-specimens often bent or crumpled).
-Teeth conical, 3-8/3-10.
-Nostrils separate, circular, equal in size, anterior above posterior which is on a level with lower rim of eye; distance of nostrils about half the distance posterior to eye; axis of nostrils cuts axis of head at an angle of about 60°.
-Eye diameter 17-22 % head length, 30 -49 % postorbital length.
-Opercular cleft curved, 29-41 % head length, 41-59 % head depth.
-Dorsal fin 34-39 fin-rays, base of D 28 32 % SL, anal fin 32-36 rays, base of A 25-26 % SL, origin of D before origin of A, end of D more or less opposite end of A. Predorsal length 49-55 % SL, preanal length 51-55 % SL.
-Pectoral fin pointed, extending to middle of pelvic fin. V is closer to P than to A.
-Caudal fin large, pointed, basal half scaled. 85-95 scales in lateral line; 16 round caudal peduncle.
-Caudal peduncle 19-23 % SL, its depth 5-6 % SL, 25-28 its length.
-Coloration Silvery, back brown, countershaded; a dark vertical bar between D and A in some habitats may be visible.
Type locality
Marcusenius abadii »Djebba, Upper Niger«, its synonym Marcusenius gilli »Assay, Lower Niger«.
Distribution
Niger, Bénoué and Volta rivers; Geba river, Lower Niger.