Stomatorhinus polylepis Boulenger, 1899
Species overview
Small fish, body moderately elongate, head longer than body depth and its own depth, snout rounded to truncate, feebly protruding mouth which is slightly subterminal; caudal peduncle moderately deep. Uniform purplish brown. Size observed: 102 mm SL, 117 mm TL.
S. polylepis(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed, cross section oblong-oval, body depth 21-27 % SL, greatest depth at about middle of body.
-Head length 27-33 % SL; head depth 17-23 % SL, 80-89 % body depth.
-Outline of back straight, upper profile of head convex, underside of head concave, outline of belly slightly convex to straight.
-Snout truncate to rounded, 13-26 % head length, 20-39 % postorbital length.
-Mouth 13-19 % head length, slightly subterminal, its edge behind posterior nostril, upper jaw on a level with lower edge of opercular cleft.
-Chin inconspicuous.
-Teeth notched, 7/8.
-Nostrils clearly separate, posterior nostril oval, anterior on a level with lower margin of lens, posterior nostril close to edge of mouth.
-Eye very small, 8-12 % head length, 12-19 % postorbital length.
-Opercular cleft curved, 30-38 % head length, 42-61 % head depth.
-Dorsal fin 18-19 fin-rays, base of D 20-26 % SL, anal fin 20-23 rays, base of A 18-26 % SL, origin of D more or less opposite origin of A, end of D more or less opposite end of A; predorsal length 60-65 % SL, preanal length 57-63 % SL.
-Pectoral fin obtusely pointed, extending to middle of pelvic fin. V is closer to P than to A.
-Caudal fin rounded, the scaled lobes rounded, extending to about 1/4 to 1/3 the length of the fin. 54-64 scales in lateral line, only 45-55 with pores; 20-22 scales round caudal peduncle.
-Caudal peduncle 12-17 % SL, its depth 5-7 % SL, 37-57 % its length.
-Coloration »Dark purplish brown, lighter beneath; fins grey«.
Type locality
»Coquilhatville et Isangila«. (Coquilhatville, recently Mbandaka 0°04 ‘ N 18° 16 ‘ E) Democratic Republic of Congo.
Distribution
»Congo, central basin; Niari-Kouilou. « (Niari-Kouilou 3° 56 ‘ S 12° 12 ‘ E.) Zaïre-Equateur and Zaïre-Central, districts of Democratic Republic of Congo..