Myomyrus macrodon Boulenger, 1898
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 rounded, protruding mouth which is clearly inferior, caudal fin rounded. Head with clusters of cutaneous sensory organs. Size observed: 381 mm SL; 430 mm TL.
M. macrodon(measurements)
Taxonomic description
-Body moderately elongate and deep, laterally compressed, cross section oblong-oval, body depth 21-24 % SL, greatest depth at origin of dorsal fin.
-Head length 24-26 % SL; head depth 24-26 % SL, 72-89 % body depth.
-Outline of back, dorsal fin inclusive, convex, upper profile of head between level of opercular cleft and nostrils convex, end of snout strongly convex, underside of head concave to straight, outline of belly more or less straight.
-Snout rounded, short, 24-29 % head length, 39-46 % postorbital length.
-Mouth 12-17 % head length, inferior, edge of mouth below anterior nostril, upper jaw on a level between base of pectoral fin and underside of head.
-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, feebly oval, on a level quite below the eyes, anterior nostril below posterior one, distance between nostrils 10-17 % snout length, distance from eye 36-54 % snout length, their axis inclined forward at an angle below 30°.
-Eye rather small, slightly oval, diameter 5-13 % head length, 8-20 % postorbital length.
-Opercular cleft slightly curved 24-30 % head length, 32-42 % head depth.
-Dorsal fin 38-42 fin-rays, base of D 42-49 % SL, anal fin 26-30 rays, base of A 25-31 % SL, origin of D far before origin of A, behind origin of pelvic fin, end of D slightly behind end of A; predorsal length 36-46 % SL, preanal length 53-60 % SL.
-Pectoral fin obtusely pointed, extending beyond base of pelvic fin. V is clearly closer to P than to A.
-Caudal fin rounded or obtusely pointed, the scaled lobes rounded, extending over 3/4 of the entire fin. 88-93 scales in lateral line; 16-20 round caudal peduncle.
-Caudal peduncle slender 11-14% SL, its depth 4-5 % SL, 23-43 % its length.
-Coloration »Pale brownish above, whitish below« countershaded.
Type locality
»Matadi, bas Congo« (5° 49 ‘ S 13° 27 ‘ E) Lower Zaïre; Democratic Republic of Congo.
Distribution
Congo basin.