Mormyrus macrocephalus Worthington, 1929
Species overview
Large fish, body moderately elongate and deep, head longer than body depth, snout blunt, funnel-shaped, not bent downwards, mouth terminal. No conspicuous cutaneous sensory organs below the eye. Caudal peduncle rather deep. Brown above, pale beneath, countershaded. Size observed: 420 mm TL.
M. macrocephalus(measurements)
Taxonomic description
-Body moderately elongate and deep, laterally compressed, cross section oblong-oval, body depth 19-24 % SL, greatest depth at origin of dorsal fin.
-Head length 26-29 % SL; head depth 16-19 % SL, 75-96 % body depth.
-Outline of back (dorsal fin inclusive) slightly convex, upper profile of head convex, underside of head concave, outline of belly slightly convex, no step at base of anal fin.
-Snout rounded, blunt, funnel-shaped, 21-31 % head length, 33-50 % postorbital length, Mouth 12-15 % head length, terminal, edge of mouth far away from anterior nostril, edge of upper jaw on a level with midline of head..
-Chin with moderate submental swelling, lower jaw less deep than upper part of snout.
-Teeth notched, 8-12/12-16.
-Nostrils separate, anterior nostril circular, posterior slightly oval and on a level with lower rim of eye, their axis cutting axis of head at an angle of about 40°.
-Eye slightly oval, its diameter 6-16 % head length, 9-26 % postorbital length. No conspicuous cutaneous sensory organs below the eye.
-Opercular cleft curved, 36-44 % head length, 56-69 % head depth.
-Dorsal fin 64-70 fin-rays, base of D 52-60 % SL, anal fin 17-20 rays, base of A 10-13 % SL, origin of D far before origin of A, halfway between pectoral and pelvic fin, end of D far behind end of A; predorsal length 34-38 % SL, preanal length 63-65 % SL.
-Pectoral fin obtusely pointed, originating close to opercular cleft, at its lower half, extending over 1/2 to 2/3 the distance to pelvic fin. V is slightly closer to A than to P or equally distant.
-Caudal fin obtusely pointed, the scaled lobes covering 3/4 of the entire fin. 83-97 scales in lateral line; 30-34 round caudal peduncle.
-Caudal peduncle 10-12% SL, its depth 7-8 % SL 62-75 % its length.
-Coloration »Dull bronze above, paler below«, countershaded.
Type locality
»Lakes Kwania, Kioga, and the Victoria Nile between Namasagali and Atura«. (Namasagali 01° 01 ‘ N 32° 57 ‘ E) Uganda.
Distribution
»Uganda, (Lakes Kyoga, 1° 30 ‘ S 33° 00 ‘ E, and Kwania), Victoria Nile (2° 14 ‘ S 31° 26 ‘ E) and dams in the Teso district«.