Mormyrus tapirus Pappenheim, 1905
Species overview
Large fish, body moderately elongate and deep, head with funnel-shaped, pointed snout, moderately bent down, mouth terminal with thick lips. No conspicuous cutaneous sensory organs below the eye. No step in ventral outline at base of anal fin. Caudal peduncle slender. Size observed: 430 mm SL.
M. tapirus(measurements)
Taxonomic description
-Body both moderately elongate and deep, laterally compressed, cross section oblong-oval, body depth 19-25 % SL, greatest depth at origin of dorsal fin.
-Head length 24-31 % SL; head depth 13-19 % SL, 66-87 % body depth.
-Outline of back (dorsal fin inclusive) convex, upper profile of head more or less straight, above eye convex, upper profile of snout feebly concave, underside of head concave, outline of belly (base of anal fin inclusive) curved, no step at base of pelvic fin.
-Snout funnel-shaped, pointed, 41-57 % head length, 90-148 % postorbital length.
-Mouth 8-11 % head length with terminal with thick lips, the lower one as broad flap protruding in front, edge of mouth far away from anterior nostril, edge of upper jaw on a level below underside of head.
-Chin with moderate submental swelling, lower jaw deeper than upper part of snout.
-Teeth notched 3-6/5-10.
-Nostrils separate, sometimes oval, anterior on a level with lower rim of eye, posterior below it, their axis cutting axis of head at an angle of 60° or more.
-Eye oval, its greatest diameter 11-22 % head length, 26-50 % postorbital length. No conspicuous tuberous organs, electroreceptors, below the eye.
-Opercular cleft curved, 26-37 % head length, 37-58 % head depth.
-Dorsal fin 60-74 fin-rays, base of D 48-56 % SL, anal fin 21-29 rays, base of A 9-20 % SL, origin of D very far before origin of A, slightly before base of pelvic fin, end of D far behind end of A; predorsal length 33-47 % SL, preanal length 57-64 % SL.
-Pectoral fin pointed, originating very close to and at lower edge of opercular cleft , extending beyond base of pelvic fin. V is closer to P than to A.
-Caudal fin pointed, the scaled lobes extending over 3/4 of the entire fin. 83-97 scales in lateral line; 10-15 round caudal peduncle.
-Caudal peduncle slender, 12-17 % SL, its depth 4-6 % SL, 28-40 its length.
-Coloration M. tapirus: »Brownish above, silvery white beneath« countershaded.
M. goheeni: »Colour in alcohol largely dull dusky-brown, mostly uniform.
-Dorsal with median longitudinal brownish band obscurely. Outer portions of caudal lobes, front of anal, and ends of paired fins with dusky to blackish tints. Head, belly, and basal portion of pectoral paler than upper surfaces«. Countershaded.
Type locality
M. tapirus: »Lokundje River., Kamerun« (3° 10 ‘ N 11° 30 ‘ E)
M. goheeni: »St. Paul’ s River, Liberia« (6° 23 ‘ N 10° 48 ‘ W)
Distribution
Coastal basins of Guinean Regions - Guinea, Liberia, Sierra Leone - and Cameroon, Sanaga River (3° 55 ‘ N 9° 38 ‘ E); never recorded from locations in between.