Mormyrus caschive Linné, 1758
Species overview
Large fish, body moderately elongate and deep, origin of dorsal fin well before origin of pelvic fin, base of anal more or less steeply ascending to caudal peduncle.
-Head about as long as body depth, snout sharp-snouted, tapering into narrow tube, slightly bent down, mouth terminal. Two conspicuous cutaneous sensory (tuberous) organs below the eye. Size observed: 520 mm TL.
M. caschive(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed, cross section oblong-oval, body depth 19-28 % SL, greatest depth at origin of dorsal fin.
-Head length 23-27 % SL; head depth 14-24 % SL, 64-96 % body depth.
-Outline of back (dorsal fin inclusive) convex, upper profile of head up to the eye concave, underside of head concave, outline of belly, up to base of pelvic fin, slightly convex, base of anal rather steeply ascending to caudal peduncle.
-Snout funnel-shaped, pointed, slightly compressed, 38-46 % head length, 74-91 % postorbital length.
-Mouth 9-12 % head length, terminal, edge of mouth far away from anterior nostril, edge of upper jaw on a level with lower edge base of pectoral fin. with thick lips.
-Chin with moderate submental swelling, lower jaw about as deep as upper part of snout.
-Teeth notched, 5-7/8-12.
-Nostrils separate, oval, anterior nostril on a level with lower rim of eye, posterior one below it, their axis cutting axis of head at an angle of about 45°.
-Eye diameter 10-14 % head length, 22-29 % postorbital length. Two conspicuous tuberous organs, special electroreceptors, below the eye.
-Opercular cleft curved 31-39 % head length, 39-61 % head depth.
-Dorsal fin 76-90 fin-rays, base of D 50-58 % SL, anal fin 18-21 rays, base of A 8-10 % SL, origin of D far before origin of A, above about half the distance between P and V, end of D far behind end A; predorsal length 34-42 % SL, preanal length 59-64 % SL.
-Pectoral fin obtusely pointed, its origin at lower half of opercular cleft, in length extending over 4/5 the distance to pelvic fin. V is almost equally distant to P and to A.
-Caudal fin obtusely pointed, the scaled lobes obtusely pointed, covering 4/5 of the entire fin. 100-130 scales in lateral line; 26-30 round caudal peduncle.
-Caudal peduncle 10-15 % SL, its depth 5-7 % SL, 41-57 % its length.
-Coloration »Olive above, whitish below«, countershaded.
Type locality
M. caschive and geoffroyi: »Nil / Nile«, M. longipinnis: »?aus dem Fischmarkte in Cairo«, M. jubelini : »Riv. Sénégal«.
Distribution
M. caschive : »Lower Nile and Bar-el-Jebel, Lakes Edward, George and Albert (Lake Mobutu), Albert and Murchinson Niles near the delta.« M. jubelini: Type locality, Senegal, West Africa.