Marcusenius bentleyi (Boulenger, 1897)
Species overview
Medium-sized fish, body elongate, moderately deep, head uneven blunt-snouted, longer than body depth, snout rather conical; uniform dark olive. Size observed: 264 mm SL, 298 mm TL. Only known from a type specimen.
M. bentleyi(measurements)
Taxonomic description
-Body elongate, cross section ovoid, body depth 20 % SL, greatest depth close to dorsal fin.
-Head longer than deep, head length 22% SL, 109 % body depth; head depth 16 % SL, 79 % body depth.
-Outlines of back and belly more or less straight; upper profile of head concave, underside of head concave.
-Snout conical, 22 % head length, 30 % post-orbital length.
-Mouth, 18 % head length, terminal, its edge before anterior nostrils, upper jaw on a level with lower rim of eye.
-Chin with thick globular swelling.
-Teeth notched, 7/10.
-Nostrils separate, circular, anterior nostril almost on backside of snout, on a level with upper rim of lens, posterior on level of centre of eye. Axis of nostrils cutting axis of head at an angle of about 30°.
-Eye small, upper rim close to front, its diameter 11 % head length, 16 % postorbital length.
-Opercular cleft curved, 53 % head length, 74 % head depth.
-Dorsal fin 23 fin-rays, base of D 20 % SL, anal fin 34 rays, base of A 27 % SL; origin of D behind origin of A, end of D before end of A; predorsal length 59 % SL, preanal length 57 % SL.
-Pectoral fin pointed, extending to middle of pelvic fin. V is closer to P than to A.
-Caudal fin membrane pointed, scaled lobes obtusely pointed, covering 2/3 of entire fin. 58 scales in lateral line, 12 round caudal peduncle.
-Caudal peduncle 17 % SL, its depth 6 % SL, 38 % its length.
-Coloration Uniform dark brown.
Type locality
»Stanley Falls, according to label BMNH« (Chutes Ngaliéma or Boyoma Falls, Congo river, 00° 50 ‘ N 25° 50 ‘ E, Haut-Zaïre; Democratic Republic of Congo)
Distribution
Congo river, type locality.