Campylomormyrus elephas (Boulenger, 1898)
Species overview
Large fish, body moderately elongate, head trunk-shape snouted, snout or rostrum moderately long, bent down, compressed, rather deep; bases of dorsal and anal fins of nearly equal length, all fins pointed. Back brownish, belly lighter, countershaded, in juveniles black bar between unpaired fins. Size observed: 381 mm SL.
C. elephas(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed body depth 24-30 % SL, greatest depth close to anal fin; head length, without snout, 16-23 % SL, 23-30 % SL snout inclusive, head depth 16-25 % SL, 64-87 % body depth.
-Outline of back nearly straight, upper profile of head strongly convex, in juveniles on back of snout slightly concave, underside of head strongly concave, lower outline of snout almost rectangular to outline of throat, outline of belly slightly convex.
-Snout moderately long, 110-150 % postorbital length, strongly compressed, distally nearly as deep as eye diameter. (The extreme shape of the snout changes with age/size of the fish, in juveniles it is much less obvious).
-Mouth small, directed forward-downward, edge of mouth very far away from nostrils, upper jaw well below head.
-Chin with submental swelling, with thick barbel as long as eye diameter.
-Teeth conical, 3/4.
-Nostrils separate, both below the eye, the anterior nostril very close to front contour, circular, a little higher than posterior nostril which is oval and about 1/2 eye diameter away from the eye axis of nostrils runs more or less parallel to axis of head.
-Eye moderate, 27-35 % postorbital length in diameter, situated in juveniles at median line of head, in larger specimens a little above, about 1/2 its diameter away from front contour.
-Opercular cleft straight, its upper part in larger specimens caudally prolonged, 33-35 % head depth.
-Dorsal fin 31-35 rays, anal 33-37, both nearly equal in length of base, 28-31 % SL, D originating behind origin of A, ending before end of A. Predorsal length 56-59 % SL, preanal length 52-57 % SL.
-Pectoral fin pointed, originating close to middle of opercular cleft, extending beyond middle or 2/3 the length of pelvic. V closer to P than to A.
-Caudal fin pointed, scaled lobes short, membranes long. 70-80 scales in lateral line, 12 around caudal peduncle. Length of caudal peduncle 14-19 % SL, its depth 5-9 % SL, 26-34 % its length.
-Coloration »Brownish above, lighter below, slightly countershaded, in juveniles with a blackish rhomboidal marking between origins of D and A, bordered white with yellow hue, anterior white band continuing up to head in small specimens; the posterior bright band vanishes first in larger fish, the anterior one later. In young border of D and A lighter, followed by a black band which extends to the pointed tips of the fins, the next fin-rays are dark on the base, pale at the tips, the last rays pale.
-Caudal membranes with bright borders, followed first by a dark, then by a pale band. In large specimens all fins quite uniform dark brown«.
Type locality
»Upoto« Upper Congo (02° 00 ‘ N 21° 30 ‘ E). Haut-Zaïre, Democratic Republic of Congo.
Distribution
Congo basin.