Genyomyrus donnyi Boulenger, 1898.
Species overview
Large fish, moderately elongate and deep, snout funnel-shaped, not bent down, terminal mouth with long barbel. Size observed: 423 mm SL, 470 mm TL.
G. donnyi(measurements)
Taxonomic description
-Body moderately elongate, laterally compressed, body depth 25-28 % SL, greatest depth close to anal fin, head length 26-29 % SL, slightly more than body depth, head depth 17-18 % SL, 67-71 % body depth.
-Outlines of back and belly slightly curved, upper profile of head slightly concave, underside of head concave.
-Snout tapering, not bent or curved, mouth a little below median axis of body.
-Snout 37-41 % head length, 74-82 % postorbital length.
-Mouth terminal, edge of mouth far away from nostrils, upper jaw on midline of head; mouth width 8-11 % head length, 24-30 % snout length.
-Chin fleshy with long, tapering barbel, almost as long as snout, pointing forwards in life specimens. Numerous teeth, »?in the jaws very small, slender, conical, disposed irregularly in several rows, forming a villiform band«. Nostrils circular, separate, anterior level with centre, posterior with lower rim of eye, distance between nostrils 5-8 % snout length, i. e. same distance anterior to front, distance posterior to eye 23-30 % snout length; axis of nostrils cuts axis of head at an angle of about 40°.
-Eye small, upper rim close to front contour.
-Opercular cleft curved, 29-36 % head length, 41-58 % depth of head.
-Dorsal fin 31-34 rays, base of D 24-26 % SL, anal 36-38 rays, base of A 28-30 % SL. D originating slightly behind A, ending before A; predorsal length 62-68 % SL, preanal length 58-62 % SL.
-Pectoral obtusely pointed, extending up to middle of pelvic which is closer to P than to A.
-Caudal with pointed scaled lobes, membranes rounded. 78-82 scales in lateral line, 12 round caudal peduncle. Length of caudal peduncle 13-18 % SL, depth 5-6 % SL, 25-35 % its length.
-Coloration Back brownish, lighter below, countershaded.
Type locality
»Upoto, localité située sur le Congo, par environ 2° N et 21° 30’ E de Greenwich«.
Distribution
Central Congo basin.