Stomatorhinus walkeri (Günther, 1867)
Species overview
Small fish, body moderately elongate and deep, head slightly longer than body depth, longer than deep, snout rounded, slightly protruding mouth which is slightly subterminal; caudal peduncle short, deep. Uniform brown. Size observed: 86 mm SL, 100 mm TL.
S. walkeri(measurements)
Taxonomic description
-Body moderately elongate and deep, laterally compressed, cross section oblong-oval, body depth 25-29 % SL, greatest depth at about middle of body.
-Head length 26-31 % SL; head depth 20-24 % SL, 74-85 % body depth.
-Outline of back straight or feebly convex, upper profile of head convex, sloping down, underside of head concave, outline of belly slightly convex.
-Snout truncate, slightly protruding mouth, 16-19 % head length, 25-30 % postorbital length.
-Mouth 14-18 % head length, slightly subterminal, its edge below anterior rim of eye, upper jaw on a level with lower edge base of pectoral fin.
-Chin inconspicuous.
-Teeth notched, 9-10/9-10.
-Nostrils clearly separate, posterior nostril oval, anterior on a level with lower rim of lens, posterior nostril close to edge of mouth.
-Eye diameter 12-16 % head length, 19-25 % postorbital length.
-Opercular cleft curved, 29-36 % head length, 38-46 % head depth.
-Dorsal fin 18-20 fin-rays, base of D 19-25 % SL, anal fin 22-25 rays, base of A 23-29 % SL, origin of D behind origin of A, end of D more or less opposite to end of A; predorsal length 62-64 % SL, preanal length 58-60 % SL.
-Pectoral fin obtusely pointed, reaching nearly to middle of pelvic fin. V is closer to P than to A.
-Caudal fin rounded, the scaled lobes rounded, extending over about 1/3 the length of the fin. 50-53 scales in lateral line, only about 40 with pores; 16 scales round caudal peduncle.
-Caudal peduncle 13-19 % SL, its depth 5-6 % SL, 30-46 % its length.
-Coloration »Brown«. Fin-rays blackish, membranes except for anterior portions of D and A, which are pigmented, transparent.
Type locality
S. walkeri: »River Ogowe (Gabon)«.
M. affinis: »Riv. Ogôoué, à Doumé (Congo français)« recently Gabon and Rep. Congo-Brazzaville.
Distribution
»Ogowe; Niari-Kouilou«. Gabon; Rep. Congo-Brazzaville. (Niari-Kouilou: 3° 56 ‘ S 12° 12 ‘ E).