Brienomyrus (Brienomyrus) retrodorsalis (Nichols and Griscom, 1917)
Species overview
Small fish, body quite elongate, unpaired fins positioned back, dorsal fin posterior to anal, eye very small. Size observed: 111 mm SL.
B. retrodorsalis(measurements)
Taxonomic description
-Body slim, elongate, body depth 22 % SL, greatest depth above pelvic fin; head length little more than body depth, head depth 17 % SL, 79 % body depth.
-Outline of back almost straight, outline of belly slightly curved; front profile steeply curved.
-Snout short, 18 % head length, 27 % postorbital length; mouth small, subterminal; chin inconspicuous, not fleshy or swollen.
-Teeth notched 7/8.
-Nostrils separate, circular, midway between eye and end of snout, their axis rather steeply inclined to axis of head, anterior nostril on a level with centre, posterior with lower margin of eye.
-Eye very small, about 10 % head length, 15 % postorbital length.
-Opercular cleft 43 % head length, 45 % head depth.
-Dorsal fin 17 fin-rays, base of D 18 % SL, anal fin 24 rays, its base 23 % SL, D originating clearly behind origin of A, ending opposite to it. Predorsal length 68 % SL, preanal length 64 % SL.
-Pectoral fin pointed, extending just to base of pelvic fin. V closer to P than to A.
-Caudal fin short, scaled lobes obtusely pointed, membranes pointed. 67 scales in lateral line, 12 scales round caudal peduncle.
-Caudal peduncle about 3 times as long as deep.
-Coloration »Uniform brownish«.
Type locality
»Niapu, Congo, ?from a small forest brook tributary to the Bima River«. (Bima riv. 03° 23 ‘ N 25° 00 ‘ E)
Distribution
Type locality, Democratic Republic of Congo.