Mormyrus caballus Boulenger, 1898
Mormyrus caballus caballus Boulenger, 1898.
Species overview
Large fish, body moderately elongate, rather deep, head bluntly tapering, bent down, with funnel-shaped, downward bent snout, terminal mouth; no conspicuous cutaneous sensory organs below the eye. Coloration countershaded, back blue-grey, belly whitish.
Size observed: 470 mm SL, 546 mm TL.
M. cab. caballus(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed, rather deep, cross section oblong-oval, body depth 22-27 % SL, greatest depth at origin of dorsal fin.
-Head about as long as body depth, 22-27 % SL; head depth 16-20 % SL, 69-79 % body depth.
-Outline of back (dorsal fin excluded) convex, upper profile of head up to the eye convex, upper side of snout feebly concave, underside of head concave, outline of belly up to caudal peduncle slightly convex, no step at base of anal fin to caudal peduncle.
-Snout funnel-shaped, blunt, slightly compressed, 29-52 % head length, 57-103 % postorbital length, edge of upper jaw on a level with lower edge opercular cleft.
-Mouth 10-20 % head length, terminal, directed forward, lips rather thick, edge of mouth far away from anterior nostril.
-Chin with moderate submental swelling, lower jaw about as deep as upper part of snout.
-Teeth notched, 5-7/8-10.
-Nostrils separate, oval anterior nostril a little below level of lower rim of eye, posterior below it, their axis cutting axis of head at an angle of about 45°.
-Eye diameter 14-23 % head length, 28-46 % postorbital length. Opercular cleft strongly curved, 33-46 % head length, 38-61 % head depth.
-Dorsal fin 60-70 fin-rays, base of D 46-52 % SL, anal fin 22-26 rays, base of A 15-19 % SL, origin of D far before origin of A, end of D far behind end A; predorsal length 35-38 % SL, preanal length 51-61 % SL.
-Pectoral fin rounded, extending to base of pelvic fin, its base is close to lower edge of opercular cleft. V is slightly closer to P than to A.
-Caudal fin with obtusely pointed membranes, the scaled lobes pointed, extending over 3/4 of the entire fin. 83-100 scales in lateral line; 12-14 round caudal peduncle.
-Caudal peduncle 13-16 % SL its depth 4-5 % SL, 28-39 its length.
-Coloration »Bluish grey above, whitish below«, countershaded.
Type locality
M. caballus: »Upoto«, Haut Congo (2° 00 ‘ N 21° 30 ‘ E);
M. curvifrons: »Mokaka: Mission de l’ Ouest africain (M. de Brazza.)«.
Distribution
»Zaïre (Congo) River up to Stanleyville (Kisangani), central basin: Democratic Republic of Congo and Angola«.