Campylomormyrus rhynchophorus (Boulenger, 1898)
Species overview
Large fish, body moderately deep, snout trunk-shaped, moderately long, inclination about 45°. Size observed: 350 mm SL.
C. rhynchophorus(measurements)
Taxonomic description
-Body laterally compressed, moderately deep, body depth 22-28 % SL, greatest depth close to anal fin.
-Head short, measured without snout, 14-22 % SL, 26-28 % SL, snout inclusive, head depth 16-22 % SL, 64-81 % body depth.
-Outline of back in juveniles straight, in larger fishes convex, evenly passing into the upper profile of head which is straight or slightly convex; underside of head concave, outline of belly straight.
-Snout or rostrum moderately long, tapering, strongly compressed, straight or distally curved, its least depth about eye diameter or 3.5 to 7 times in its length, depending on the length of the specimen. (The extreme shape of the snout changes with age/size of the fish, in juveniles it is much less obvious).
-Mouth small, 6-9 % snout length, directed forward, edge of mouth very far away from anterior nostril, upper jaw well below head.
-Chin with submental swelling and a compressed barbel, one eye diameter in length.
-Teeth conical, 3-5 /4.
-Eye small.
-Nostrils separate, situated below eye, parallel to axis of head, anterior circular, posterior oval, its axis parallel to outline of snout; distance of nostrils 3-5 times in eye diameter, distance posterior nostril to eye equals eye diameter.
-Opercular cleft curved, 36-41 % head depth.
-Dorsal fin 27-31 fin-rays, anal fin 31-36, base of D 21-24 % SL, base of A 24-29 % SL, D originating behind A, ending before end of A; predorsal length 60-66 % SL, preanal length 54-63 % SL.
-Pectoral obtusely pointed, originating below middle of opercular cleft extending beyond middle of pelvic fin. V is closer to P than to A.
-Caudal fin obtusely pointed, scaled portion longer membrane, obtusely pointed. 75-85 scales in lateral line, 16 or 18 (20) around caudal peduncle; Caudal peduncle 16-20 % SL, its depth 4-6 % SL, 23-33 % its length.
-Coloration Olive brown on the back, yellowish and brighter on the flanks and below, a dark band or narrow rhomb between the origin of D and A, bordered whitish, and continuing on the anterior parts of the fins. In large specimens these markings more or less fade out.
-Pectoral and pelvic with dark bases, caudal with dark bands close to the margins.
Type locality
C. rhynchophorus: »Upoto« Upper Congo (02° 00 ‘ N 21° 30 ‘ E); G. compressirostris: »Boma (embouchure du Congo)« (05° 51 ‘ S 13° 03 ‘ E) ; G. rhynchophorus lualabaensis: »Kabelwe« Congo basin. (08 ° 44 ‘ S 26° 56 ‘ E).
Distribution
Congo basin.