Gnathonemus longibarbis (Hilgendorf, 1888)
Species overview
Medium sized fish, moderately elongate, snout funnel-shaped with slightly concave profile, terminal mouth with long, tapering barbel. Size observed: 252 mm SL, 269 mm TL.
G. longibarbis(measurements)
Taxonomic description
-Body moderately elongate and deep, laterally compressed, body depth 21-30 % SL, greatest depth between pelvic and anal fin; head length 24-27 % SL, head depth 18-26 % SL, 70-92 % body depth.
-Outlines of back and belly slightly curved, upper profile of head and underside of head slightly concave; Snout funnel shaped, 33-36 % head length, 58-67 % postorbital length.
-Mouth terminal, small, 10-12 % head length, edge of mouth far away from anterior nostril, upper jaw on a level with lower margin of the eye.
-Chin with barbel, about as long as snout.
-Teeth small, notched, 3-5/4-6.
-Nostrils separate, both circular, anterior on level with upper margin of eye, posterior on level with centre of eye, distance posterior nostril to eye 25-33 % snout length; axis of nostrils cutting axis of head at an angle of about 45°.
-Opercular cleft 29-46 % head length, 31-62 % head depth.
-Dorsal fin 22-25 fin-rays, anal fin 28-31, base of D 16-19 % SL, base of A 21-25 % SL, margin of both fins concave; D originating behind, ending before A, predorsal length 65-71 % SL, preanal length 60-65 % SL. Base of pectoral fin close to middle of opercular cleft, P obtusely pointed, extending to base of pelvic or little beyond; V closer to P than to A..
-Caudal fin with long scaled lobes, obtusely pointed. 58-64 scales in lateral line, (10) 12 round caudal peduncle.
-Caudal peduncle 13-17 % SL, its depth 6-8 % SL, 39-53 % its length.
-Coloration Uniform blackish, rarely faint traces of a black bar between D and A; throat may be whitish.
Type locality
»Victoria-Nyanza (Ukerewe See)« (01° 00 ‘ S 33° 00 ‘ E)
Distribution
»Lake Victoria, Lake Tanganyika, Victoria Nile (Zambese?)«