Mormyrus caballus Boulenger, 1898
Mormyrus caballus lualabae Reizer, 1964
Species overview
Large fish, quite similar to Mormyrus c. caballus, body moderately elongate, rather deep, head strongly convex with funnel-shaped, slightly downward bent snout, terminal mouth, underside of head concave; no conspicuous cutaneous sensory organs below the eye. Coloration countershaded. Size observed: 295 mm SL, 346 mm TL.
M. cab. lualabae(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed, rather deep, cross section oblong-oval, body depth 20-27 % SL, greatest depth at origin of dorsal fin.
-Head about as long as body depth, 24-27 % SL; head depth 17-20 % SL, 69-86 % body depth.
-Outline of back , from neck to caudal peduncle, dorsal fin inclusive, convex, upper profile of head from level of eye strongly convex, outline of snout feebly concave; tip of snout strongly convex. Underside of head concave, outline of belly up to origin of caudal peduncle slightly convex, without any step at base of anal fin.
-Snout funnel-shaped, blunt, slightly compressed, 31-44 % head length, 67-98 % postorbital length, both jaws about equal in depth.
-Mouth 16-20 % head length, terminal, directed forward, edge of mouth far away from anterior nostril, edge of upper jaw on a level with lower edge base of pectoral fin.
-Chin with moderate submental swelling.
-Teeth feebly notched, 5-7/8-10.
-Nostrils separate, both more or less oval, closer to eye than to end of snout; anterior nostril well below level of lower rim of eye, posterior below it; axis of nostrils cutting axis of head at an angle of about 45°.
-Eye moderate, its diameter 15-18 % head length, 31-37 % postorbital length. Opercular cleft strongly curved, 36-47 % head length, 51-66 % head depth.
-Dorsal fin 60-69 fin-rays, base of D 48-51 % SL, anal fin 22-24 rays, base of A 15-16 % SL, origin of D far before origin of A, above base of pelvic fin, end of D far behind end A; predorsal length 35-38 % SL, preanal length 54-59 % SL.
-Pectoral fin obtusely pointed, extending to base of pelvic fin or slightly beyond, its base is close to lower edge of opercular cleft. V is slightly closer to P than to A.
-Caudal fin large with pointed membranes, the scaled lobes pointed, extending over 3/4 of the entire fin. Number of scales in lateral line not indicated by author of subspecies; 16 round caudal peduncle.
-Caudal peduncle 12-16 % SL, its depth 5-6 % SL, 36-41 % its length.
-Coloration as in other M. caballus countershaded (no indication in description).
Type locality
»Kindu, fl. Lualaba« (2° 57 ‘ S 26° 56 ‘ E) Democratic Republic of Congo.
Distribution
»Upper Congo basin, from Stanleyville [Kisangani, 0° 25 ‘ N 25° 12 ‘ E] up to Nyonga (except Lufira River above rapids and Luapula River)« Democratic Republic of Congo.