Brienomyrus (Brienomyrus) adustus (Fowler, 1936)
Species overview
Small fish, moderately elongate, snout short, slightly tapering, rounded, slightly protruding mouth; pectoral fin pointed, dorsal fin originating considerably posterior to origin of anal fin. Brown, marbled or clouded darker. Size observed: 86 mm SL.
B. adustus(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed, cross section oblong-oval, body depth 19-22 % SL, greatest depth between pelvic and anal fin.
-Head length 21-23 %L, head depth 15-16 % SL, 69-81 % body depth.
-Outline of back slightly curved, upper profile of head straight, inclined to tip of snout which is round, underside of head more or less concave, outline of belly rather straight.
-Snout 23-24 % head length, 37-42 % postorbital length.
-Mouth 16-20 % head length, subterminal, its edge extending to a line underneath posterior nostril, upper jaw on a level with lower edge of origin of pectoral fin.
-Chin inconspicuous, without appendage.
-Teeth truncate, slightly notched, 5-6/6.
-Nostrils separate, circular, anterior nostril on a level with centre of eye, posterior much deeper, axis of nostrils cutting axis of head at an angle of more than 40°.
-Eye small 10-14 % head length, 16-25 % postorbital length, with dark grey iris.
-Opercular cleft rounded, 43-48 % head length, 58-68 % head depth.
-Dorsal fin 16-18 fin-rays, base of D 13-17 % SL, anal fin 27-30 rays, base of A 26-30 % SL. Origin of D opposite to middle of A, end of D anterior to end of A; predorsal length 68-71 % SL, preanal length 58-62 % SL.
-Pectoral fin pointed, extending to about middle of pelvic fin. V is closer to P than to A.
-Caudal fin obtusely pointed, scaled portion rounded, less than half as long as total fin. 51-53 scale in lateral line, 12 around the caudal peduncle.
-Caudal peduncle 16-18 % SL, its length 5-7 % SL, 27-35 % its length.
-Coloration, brown, marbled or clouded with dark or blackish brown on trunk and tail, head and belly densely speckled dark or blackish brown. Fin rays in D and A dark, fin membrane pale, transparent; P and V dark grey, C dark grey at base, rest whitish.
Type locality
»30 kilometres east of Kribi, Cameroon. (Kribi: 02° 57’ N, 09° 55’ E.)
Distribution
Coastal rivers of Cameroon, (types locality)