Stomatorhinus humilior Boulenger, 1899
Species overview
Small fish, body quite elongate, head longer than body depth and its own depth, snout truncate, not protruding mouth which is slightly subterminal; caudal peduncle short, deep. Dark purplish brown. lighter beneath, light dots on head.
Size observed: 75.5 mm SL, 86 mm TL.
S. humilior(measurements)
Taxonomic description
-Body rather elongate, laterally compressed, cross section oblong-oval, body depth 20-23 % SL, greatest depth between pelvic and anal fin.
-Head length 21-33 % SL; head depth 16-22 % SL, 81-100 % body depth.
-Outlines of back and belly more or less straight, upper profile of head convex, underside of head concave.
-Snout truncate, 19-25 % head length, 27-38 % postorbital length.
-Mouth width 11-19 % head length, slightly subterminal, its edge behind posterior nostril, upper jaw on a level with lower edge base of pectoral fin.
-Chin inconspicuous.
-Teeth notched, 7/8.
-Nostrils clearly separate, posterior nostril probably oval, anterior on a level with lower margin of lens, posterior nostril close to edge of mouth.
-Eye diameter very small, 9-13 % head length, 12-20 % postorbital length.
-Opercular cleft curved, 26-36 % head length, 41-55 % head depth.
-Dorsal fin 17-19 fin-rays, base of D 19-23 % SL, anal fin 20-22 rays, base of A 22-26 % SL, origin of D more or less opposite to origin of A, end of D more or less opposite to end of A; predorsal length 60-64 % SL, preanal length 57-64 % SL.
-Pectoral fin obtusely pointed, extending beyond middle of pelvic fin. V is closer to P than to A.
-Caudal fin obtusely pointed, the scaled lobes rounded, short, extending over 1/4 - 1/3 of the fin. 50-53 scales in lateral line, only 26-40 with pores; 14-16 scales round caudal peduncle.
-Caudal peduncle 16-21% SL, its depth 5-7 % SL, 28-47 % its length.
-Coloration »Dark purplish brown, lighter beneath; head with light dots«. Fin-rays dark, membranes transparent.
Type locality
»Ibali et Coquilhatville«. (Ibali: 3° 37 ‘ S 16° 05 ‘ E, Coquilhatville, recently Mbandaka: 0° 04 ‘ N 18° 16 ‘ E) Democratic Republic of Congo.
Distribution
»Democratic Republic of Congo, central basin,« districts Bandundu and Equateur.