Mormyrops (Mormyrops) sirenoides Boulenger, 1898
Species overview
Large fish, body much elongate, moderately compressed, low, tail region tapering; snout truncate, protruding mouth; dark, slightly countershaded. Size observed: 598 mm SL, 630 TL.
M. sirenoides(measurements)
Taxonomic description
-Body much elongate, moderately laterally compressed, cross section oblong-oval, body depth 13-16 % SL, greatest depth between pectoral and pelvic fin.
-Head length 23-26 % SL, (in very large specimens much less: 17 % SL in the type), head depth 12-14 % SL, 81-98 % body depth.
-Outline of back straight, parallel to outline of belly, upper profile of head straight to feebly concave, underside of head slightly concave to straight.
-Snout truncate, protruding mouth, 14-24 (36*) % head length, 19-33 (58) % postorbital length.
-Mouth wide, 18-21 % head length, subterminal, its edge extending to level of posterior nostril, edge of upper jaw on a level with lower edge of opercular cleft.
-Chin with moderate submental swelling, upper part of snout two times as deep as lower jaw.
-Teeth truncate, in closed lines, 12-14/12-14.
-Nostrils separate, posterior oblong, both on a level with centre of eye, their distance half the distance from eye or equidistant, their axis being parallel to axis of snout.
-Eye diameter (3) 5-10 % head length, (5) 6-14 % postorbital length.
-Opercular cleft curved 24-36 (39) % head length, 33-68 % head depth.
-Dorsal fin 29-32 fin-rays, base of D 21-26 % SL, anal fin 45-47 rays, base of A 32-37 % SL, origin of D well behind A, end of D well before end A; predorsal length 61-67 % SL, preanal length 55-57 (59) % SL.
-Pectoral fin rounded, its base very close to opercular cleft, extending to about half its distance from pelvic fin. V is slightly closer to P than to A.
-Caudal fin rounded, the scaled lobes covering half of the entire fin. 90-95 scales in lateral line; 16-18 round caudal peduncle.
-Caudal peduncle about moderate, 7-11 % SL, its depth 4-5 % SL, 36-53 % its length.
-Coloration »Uniform dark brown, somewhat lighter beneath«, slightly countershaded.
*) between brackets ( ) data of very long specimens.
Type locality
»Nouvelle-Anvers, Haut Congo«, (to day: Makanza) Democratic Republic of Congo (1° 36 ‘ N 19° 07 ‘ E).
Distribution
Middle Congo basin.