Mormyrops (Mormyrops) nigricans Boulenger, 1899
Species overview
Large fish, body moderately elongate and deep, head with concave upper profile and underside, mouth terminal; caudal fin moderately deep; dark longitudinal lines along the trunk and tail. Size observed: 368 mm SL, 391 mm SL.
M. nigricans(measurements)
Taxonomic description
-Body moderately elongate, moderately compressed, cross section oblong-oval, body depth 18-24 % SL, greatest depth at about middle of trunk.
-Head length 26-30 % SL, head depth 15-19 % SL, 72-85 % body depth.
-Outline of back straight, parallel to outline of belly, upper profile of head concave, underside of head slightly concave.
-Snout rounded, 17-23 % head length, 22-31 % postorbital length.
-Mouth 14-22 % head length, terminal, its edge at half the distance between the nostrils, edge of upper jaw on a level with upper edge base of pectoral fin.
-Chin with moderate submental swelling, lower jaw and upper part of snout of about equal depth.
-Teeth truncate, 24-28-/24-28, in closed lines.
-Nostrils separate, circular, both on a level with centre of eye or above, their axis running parallel to axis of snout.
-Eye diameter 5-8 % head length, 7-12 % postorbital length.
-Opercular cleft curved, 27-38 % head length.
-Dorsal fin 24-25 fin-rays, base of D 17-22 % SL, anal fin 38-41 rays, base of A 25-33 % SL, origin of D well behind A, end of D before end A; predorsal length 61-75 % SL, preanal length 55-67 % SL.
-Pectoral fin rounded, extending to half its distance from pelvic fin or little beyond. V is closer to P than to A.
-Caudal fin rounded, moderate, the scaled lobes covering 2/3 of the entire fin. 54-58 scales in lateral line; 12 round caudal peduncle.
-Caudal peduncle short, 6-8 % SL, its depth 4-5% SL, 58-86 % its length.
-Coloration »Blackish on the back, greyish on the belly [countershaded], sided brown, with darker longitudinal lines, with or without black blotches«.
Type locality
M. nigricans: »Kutu, Lac Léopold II« (to day Lac Mai-Ndombe) Democratic Republic of Congo (2° 44 ‘ S 18° 09 ‘ E).
M. vaillanti: »Rivière Alima à Diélé, Congo français« (Alima river: 1° 36 ‘ S °16° 36’ E), Rep. Congo Brazzaville.
Distribution
Middle Congo basin.