Hippopotamyrus pictus (Marcusen, 1864)
Species overview
Medium-sized fish, body moderately deep, head round-snouted, about as long as deep, snout rounded, not sloping down, slightly protruding mouth which is slightly subterminal; brown or dark olive, body and fins with conspicuous markings in smaller specimens.
Size observed: 300 mm SL.
H. pictus(measurements)
Taxonomic description
-Body moderately deep, body depth 21-28 % SL, greatest depth close to unpaired fins; Head about as long as deep, head length 20-23 % SL, head depth 16-21 % SL, 68-80 % body depth.
-Outline of back more or less straight, upper profile of head strongly convex, underside of head concave, outline of belly slightly convex.
-Snout rounded, 20-29 % head length, 38-48 % postorbital length.
-Mouth small, slightly subterminal, its edge below anterior to nostril, upper jaw on a level with upper edge base of pectoral fin.
-Chin with moderate submental swelling.
-Teeth notched, 4-5/5-7.
-Nostrils separate, circular, anterior on a level with centre of eye, posterior with lower margin, arranged at an angle of about 45° to axis of head or body, respectively.
-Eye diameter 19-22 % head length, 30-35 % postorbital length.
-Opercular cleft about 1/3 head depth.
-Dorsal fin 29-36 fin-rays, base of D 24-27 % SL, anal fin 30-36 rays, base of A 25-28 % SL, origins and ends of D and A more or less opposite to each other; predorsal length 55-58 % SL, preanal length both 54-58 % SL.
-Pectoral fin pointed, in length it equals head depth, extending to middle of pelvic fin. V is closer to P than to A.
-Caudal fin pointed, more than half of it is scaled. 71-88 scale in lateral line, 12-17 between lateral line and D, 14-20 between lateral line and V; 12 round caudal peduncle.
-Caudal peduncle 16-22 % SL, its depth 4-6 % SL, 21-33 % its length.
-Coloration »Brown or dark olive with yellowish bars, two of which enclose a sort of blackish rhomb between the anterior rays of the dorsal and those of the anal, which bear a black bar; a black band on the pectoral and pelvic and on each lobe of the caudal«. In large specimens less conspicuous.
Type locality
»White Nile«.
Distribution
White Nile, Cameroon, Nigeria, Gold Coast, Ivory Coast, Upper Volta, Mayo Kebi, Chari and Logone rivers. Great Sahelo-Soudanian basins.