Mormyrus tenuirostris Peters, 1882
Species overview
Large fish, body elongate, head longer than body depth with long, straight, tubular, slightly downwards curved snout, mouth terminal. No conspicuous cutaneous sensory organs below the eye.; caudal peduncle rather deep, caudal fin large. Size observed: 323 mm SL.
M. tenuirostris(measurements)
Taxonomic description
-Body elongate, laterally compressed, cross section oblong-oval, body depth 22-26 % SL, greatest depth at origin of dorsal fin.
-Head length 29-30 % SL, 112-137 % body depth; head depth 15-16 % SL, 56-72 % body depth.
-Outline of back (dorsal fin inclusive) slightly convex, upper profile of head more or less straight with a feeble depression just before the eyes; underside of head concave, outline of belly, base of anal fin inclusive, slightly convex, without a step ascending to caudal peduncle.
-Snout funnel-shaped, i. e. slightly bent narrow tube, 45-47 % head length, 100-108 % postorbital length, Mouth 6-9 % head length, terminal, edge of mouth far away from anterior nostril, edge of upper jaw on a level with lower edge of opercular cleft.
-Chin with moderate submental swelling, lower jaw about as deep as upper jaw.
-Teeth notched, 5/7.
-Nostrils separate, posterior one oval, anterior nostril on a level with lower rim of eye, posterior nostril below anterior, distance between nostrils 1/3 their distance from eye, 8-10 % head length and 24-35 %, respectively, Axis of nostrils cutting axis of head at an angle of less than 30°.
-Eye diameter 9-11 % head length, 19-25 % postorbital length. No conspicuous cutaneous organs below the eye.
-Opercular cleft curved, 27-30 % head length, 53-60 % head depth.
-Dorsal fin 60 fin-rays, base of D 42-48 % SL, anal fin 19 rays, base of A 11-13 % SL, origin of D far before origin of A, above base of pelvic fin, end of D far behind end of A; predorsal length 42-47 % SL, preanal length 60-66 % SL.
-Pectoral fin pointed, extending to base of pelvic fin. V is closer to P than to A.
-Caudal fin obtusely pointed, the scaled lobes covering at least 2/3 of the entire fin. 92 scales in lateral line; 26 round caudal peduncle.
-Caudal peduncle 12-14 % SL, its depth 6-7 % SL, 45-51 % its length.
-Coloration No information available.
Type locality
»Adi River [Athi River], Ukamba, East Africa«. (Athi 2° 59 ‘ S 38° 31 ‘ E).
Distribution
»Kenya (Athi River)«