Marcusenius senegalensis (Steindachner, 1870)
Species overview
Medium-sized fish, head uneven blunt-snouted, snout obtusely pointed; the particular populations are quite variable in shape, - being rather deep-bodied or slender - and in colour of body and there is considerable overlap in fin-ray and scale counts, depending on place of origin and with it hydrographical and nutritional conditions. Size observed: 312 mm SL.
M. senegalensis(measurements)1
M. senegalensis(measurements)2
Taxonomic description
-Body laterally compressed, moderately or quite deep, 24-32 % SL, greatest depth near anal fin or closer to pelvic.
-Head length 19-23 % SL, head depth 17-26 % SL, 62-80 % body depth.
-Outline of back more or less straight, upper profile of head convex, underside of head concave, outline of belly slightly convex.
-Snout obtusely pointed, 16-26 % head length, 25-46 % postorbital length.
-Mouth terminal, 13-23 % head length, edge of mouth before anterior nostril, tip of upper jaw on a level with centre of eye,.
-Chin with a conspicuous swelling, globular or conical in shape.
-Teeth conical, 3-5/3-6.
-Nostrils separate, circular, about as far away from eye as from outline of snout; anterior nostril on a level with upper rim of lens, posterior nostril on a level with centre of eye. Axis of nostrils cutting axis of head at an angle of about 60°.
-Eye diameter 13-18 % head length, 19-31 % postorbital length.
-Opercular cleft curved, 33-50 % head length, 44-63 % head depth.
-Dorsal fin 22-31 fin-rays, base of D 19-25 % SL, anal fin 28-38 rays, base of A 24-30 % SL, origin of D behind origin of A, end of D before end of A; predorsal length 56-69 % SL, preanal length 56-66 % SL.
-Pectoral fin pointed, nearly reaches to middle of pelvic fin, but there may be differences between popuöations. V is closer to P than to A.
-Caudal fin obtusely pointed, scaled lobes obtusely pointed, at most half as long as membranous lobes. 57-78 scales in lateral line; 12 round caudal peduncle.
-Caudal peduncle 16-29 % SL, its depth 5-7 % SL, 21-46 % its length.
-Coloration »Silvery, brown or steel-blue on the back« (Steindachner);»Deep brown to blackish on the back, paler on the sides and below; a dark streak under each scale on the upper part of the sides forming long longitudinal bands« (Svensson);
»Uniform brown-olivaceous, with traces of fine much darker parallel longitudinal lines on the back« (Pellegrin); (Pfaff only refers to preserved specimens.) Basic coloration countershaded with darker back and brighter belly.
Type locality
M. senegalensis senegalensis: »Marigot von Taoué, Dagana, « Senegal (16° 31 ‘ N 15° 30 ‘ W)
G. gambiensis: »Mc Carty Island« Gambia River, (13° 30 ‘ N 15° 40 ‘ W)
M. senegalensis pfaffi: »Kabara«, Mali
M. senegalensis gracilis: »Gribingui«, Central Africa. (Gribingui river: 08° 33 ‘ N 19° 05 ‘ E)
M. mento non Boulenger: Bas Dahomey
Distribution
Great Soudanian basins as well as in the North Guinea, but absent in coastal forest districts.