Myomyrus macrops Boulenger, 1914
Species overview
Large fish, body both moderately elongate and deep, dorsal fin long, its origin posterior to that of pelvic fin, anal fin short, ending slightly anterior to end of dorsal; snout strongly rounded, mouth inferior; caudal fin obtusely pointed. Head with clusters of cutaneous sensory organs. Size observed: 251 mm SL, 281 mm TL.
M. macrops(measurements)
Taxonomic description
-Body elongate, laterally compressed, cross section oblong-oval, body depth 19-24 % SL, greatest depth at origin of dorsal fin.
-Head length 21-25 % SL; head depth 16-19 % SL, 77-91 % body depth.
-Outline of back (dorsal fin inclusive) slightly convex, upper profile of head up to nostrils convex, underside of head concave, outline of belly, more or less straight, no step towards caudal peduncle.
-Snout blunt, truncate torounded, 20-25 % head length, 33-42 % postorbital length, clearly protruding mouth.
-Mouth inferior, 11-17 % head length, edge of mouth below anterior nostril, edge of upper jaw on a level with lower edge origin of pectoral fin.
-Chin with moderate submental swelling, lower jaw less deep than upper part of snout.
-Teeth in upper jaw conical 5-6, in lower jaw 6, compressed and the median pair very large and incisor like, projecting over the gums.
-Nostrils separate, oval or irregular in shape, quite close to tip of snout, distance between nostrils 10-21 % snout length, between nostrils and eye 33-61 %, axis of nostrils almost parallel to axis of head or tilted forwards. Orbit oval, eye rather big, its diameter 10-16 % head length, 17-26 % postorbital length.
-Opercular cleft slightly curved, 27-36 % head length, 35-57 % head depth.
-Dorsal fin 40-42 fin-rays, base of D 43-47 % SL, anal fin 26-29 rays, base of A 26-30 % SL, origin of D far before origin of A but posterior to origin of pelvic fin, end of D behind end of A; predorsal length 36-46 % SL, preanal length 48-59 % SL.
-Pectoral fin pointed, reaching to base of pelvic fin or slightly beyond. V is distinctly closer to P than to A.
-Caudal fin obtusely pointed, the scaled lobes extending over 4/5 of the entire fin. 82-87 scales in lateral line; 16 round caudal peduncle.
-Caudal peduncle 11-14 % SL, its depth 4-5 % SL, 35-46 % its length.
-Coloration »Dark brown, a little lighter beneath«.
Type locality
»Ja River and Bumba River, a tributary of the Ja«. (2° 02 ‘ N 15° 12 ‘ E) Cameroon.
Distribution
»Congo River and tributaries, Central Democratic Republic of Congo and Cameroon«..