Petrocephalus keatingii Boulenger, 1901
Species overview
Small fish, body moderately short, deep, head slightly longer than deep, snout shorter than diameter of eye, mouth inferior. Head with three aggregations, »rosettes«, of cutaneous sensory organs. Dorsal fin much shorter than anal. Caudal peduncle rather deep. Silvery, countershaded. Only known from two specimens. Size observed: 100 mm SL, 115 mm TL.
P. keatingii(measurements)
Taxonomic description
-Body moderately short, strongly laterally compressed, body depth 33-35 % SL, greatest depth above origin of anal fin.
-Head length 25-29 % SL; head depth 23-25 % SL, 68-71 % body depth.
-Outline of back and belly slightly convex, upper profile and underside of head convex. Base of dorsal and anal fin running steeply to caudal peduncle.
-Snout rounded, short, 14-15 % head length, 21-23 % postorbital length.
-Mouth width, 20-24 % head length, inferior, its edge below centre of eye, upper jaw on a level with upper edge base of pectoral fin.
-Chin inconspicuous.
-Teeth notched, 16/26.
-Nostrils closely together, upright-oval, very close to rim of eye and on a level with lower rim of lens; axis parallel to axis of head.
-Eye large, diameter 22-24 % head length, 35 % postorbital length. Three rosettes, aggregations of electrorecpetors, on the head.
-Opercular cleft strongly curved, its posterior margin caudally to base of pectoral fin, 39-46 % head length, 44-51 % head depth.
-Dorsal fin 25 fin-rays, base of D 18-19 % SL, anal fin 38-39 rays, base of A 32-35 % SL, origin of D well behind origin of A, end of D well before end of A; predorsal length 60-61 % SL, preanal length 53-55 % SL.
-Pectoral fin pointed, extending over 3/4 the length of pelvic fin. V is closer to P than to A.
-Caudal fin pointed, scaled part short. 41-44 scales in lateral line; 10-12 round caudal peduncle.
-Caudal peduncle 18-20 % SL, its depth 7 % SL, 38-40 % its length.
-Coloration »Silvery, the back and the anterior rays of the dorsal darker«, countershaded.
Type locality
»Fashoda«. Kodok, Sudan (9° 53 ‘ N 32° 07 ‘ E)
Distribution
»Nile River«.