Mormyrus caballus Boulenger, 1898
Mormyrus caballus asinus Boulenger, 1915
Species overview
Large fish, quite similar to Mormyrus c. caballus, body moderately elongate, rather deep, head strongly convex with funnel-shaped, downward bent snout, terminal mouth, underside of head concave; no conspicuous cutaneous sensory organs below the eye. Coloration countershaded, back brown, belly lighter.
Size observed: 317 mm SL, 368 mm TL.
M. cab. asinus(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed, rather deep, cross section oblong-oval, body depth 26-30 % SL, greatest depth at origin of dorsal fin.
-Head about as long as body depth, 27-28 % SL; head depth 19-20 % SL, 65-72 % body depth.
-Outline of back , from neck to caudal peduncle, convex, upper profile of head strongly convex, above eye up to tip of snout feebly to clearly concave, underside of head concave, outline of belly up to origin of caudal peduncle curved, base of anal fin not formed into steps.
-Snout funnel-shaped, blunt, slightly compressed, slightly bent down, 42-46 % head length, 85-89 % postorbital length, edge of upper jaw on a level with lower edge base of pectoral fin.
-Mouth 13-18 % head length, terminal, directed forward, its edge far away from anterior nostril.
-Chin with moderate submental swelling, lower jaw and upper part of snout about equal in depth.
-Teeth notched, 2/7.
-Nostrils separate, closer to the eye than to end of snout, both more or less oval, anterior nostril clearly below level of lower margin of eye, posterior below it, their axis cutting axis of head at an angle of about 45-60°.
-Eye moderate, its diameter 12-14 % head length, 23-27 % postorbital length. Opercular cleft strongly curved, 37-43 % head length, 53-63 % head depth.
-Dorsal fin 60-70 fin-rays, base of D 51-52 % SL, anal fin 22-26 rays, base of A 16-17 % SL, origin of D far before origin of A, end of D behind end A; predorsal length 38-43 % SL, preanal length 58-61 % SL.
-Pectoral fin rounded, extending to base of pelvic fin, its origin is close to lower edge of opercular cleft. V is slightly closer to P than to A.
-Caudal fin large with obtusely pointed membranes, the scaled lobes pointed, extending over 3/4 of the entire fin. 85-110 scales in lateral line; 16 (18) round caudal peduncle.
-Caudal peduncle 12-15 % SL its depth 5-6 % SL, 39-45 its length.
-Coloration: »Brown, lighter below«, countershaded.
Type locality
»Lac Moero, devant Lukonzolwa« Democratic Republic of Congo (8° 47' S 28° 39' E)
Distribution
»Luapula, Moero and Upper Lufira basin« Democratic Republic of Congo (about 8-12° S, 25-30° E).