Marcusenius ghesquierei (Poll, 1945)
Species overview
Small-sized fish, body rather deep, much deeper than head, head uneven blunt-snouted, dorsal fin longer than anal and originating before it, caudal fin large; countershaded, fins partially darker, darker bar between unpaired fins. Size observed: 164 mm SL.
M. ghesquierei(measurements)
Taxonomic description
-Body laterally compressed,quite deep, body depth 30-37 % SL, greatest depth anterior to dorsal fin.
-Head length 24-27 % SL, head depth 20-24 % SL, 58-66 % body depth.
-Outline of back slightly convex at a section between dorsal fin and above pelvic fin, sloping more or less steeply into the convex upper profile of head whixh is rounded at the end of the snout; underside of head slightly concave or straight, outline of belly slightly convex.
-Snout 20-28 % head length, 33-46 % postorbital length.
-Mouth 11-20 % head length, terminal, its edge below anterior nostril, upper jaw on a level with lower rim of eye. Globular swelling on chin not prominent.
-Teeth small, notched, 5/5.
-Nostrils separate, circular, posterior nostril on a level with lower margin of eye or above, anterior nostril above, axis of nostrils cuts axis at an angle of about 60°; distance of nostrils smaller than distance from eye and from end of snout.
-Eye diameter 14-21 % head length, 23-38 % postorbital length, 79-95 % snout length, distance from end of snout smaller than its diameter.
-Opercular cleft curved, 36-48 % head length, 46-56 % head depth.
-Dorsal fin 32-34 rays, base of D 28-35 % SL, anal fin 27-29 rays, base of A 22-27 % SL, origin of D before origin of A, end of D behind end of A; predorsal length 54-64 % SL, preanal length 57-60 % SL.
-Pectoral fin pointed, extending to tip of pelvic fin. V is closer to P than to A.
-Caudal fin pointed, scaled lobes extending to half the length of the entire fin. 37-42 scales in lateral line; 8 round caudal peduncle.
-Caudal peduncle 15-20 % SL, its depths 5-6 % SL, 22-38 % its length.
-Coloration Dark brown on the back, ventrally lighter, finely dotted on the scales.
-Head with yellowish regions, The brown colour is finely dotted white, An oblique dark band between the origins of D and A, covering two lateral line scales, these fins as well as the pelvic fins are partially darker, in particular at the bases.
Type locality
»Riv. Busira, région d’ Eala« Democratic Republic of Congo. (Busira r.: 0° 15 ‘ S 18° 59 ‘ E)
Distribution
Busira river, tributary of Congo river, type locality; »river Tshuapa: 0° 14’ S 20° 50’ E; village Bantoi, river RUKI: 0°04’ S 18° 19’ E; river Bokuma: 0° 06’ S 20° 50’ E«.