Petrocephalus grandoculis Boulenger, 1920
Species overview
Small fish, body moderately short and deep, head slightly longer than deep, its contours obliquely truncate, snout shorter than diameter of eye, mouth inferior. Head with three aggregations, »rosettes«, of cutaneous sensory organs. Caudal peduncle slender. Silvery, back brownish, countershaded, with blackish markings. Size observed: 115 mm SL.
P. grandoculis(measurements)
Taxonomic description
-Body moderately short and deep, strongly laterally compressed, body depth 31-37 % SL, greatest depth at origin of anal fin.
-Head length 24-30 % SL; head depth 22-30 % SL, 69-80 % body depth.
-Outlines of back more or less straight, outline of belly slightly convex, upper profile and underside of head convex: tip of head above median line of head; bases of unpaired fins running steeply to caudal peduncle.
-Snout rounded, very short, about 1/2 diameter of eye, 12-16 % head length, 21-29 % postorbital length,.
-Mouth 12-22 % head length, inferior, its edge below centre of eye or slightly anterior to it, upper jaw on a level between base of pectoral fin and underside of head.
-Chin inconspicuous.
-Teeth notched, 10-12/20.
-Nostrils closely together, oval, on a level slightly above lower rim of the eye; axis parallel to axis of head.
-Eye big, slightly oval, diameter 27-32 % head length, 46-60 % postorbital length. Three rosettes, aggregations of electrorecpetors, on the head.
-Opercular cleft strongly curved, its posterior margin extending beyond base of pectoral fin, 28-40 % head length, 24-44 % head depth.
-Dorsal fin 28-29 fin-rays, base of D 21-25 % SL, anal fin 33-34 rays, base of A 26-33 % SL, origin of D well behind origin of A, end of D well before end of A; predorsal length 57-64 % SL, preanal length 53-59 % SL.
-Pectoral fin pointed, extending nearly to the tip of pelvic fin. V is closer to P than to A.
-Caudal fin pointed, scaled part short. 38-40 scales in lateral line; 12 round caudal peduncle.
-Caudal peduncle short, slender, 15-20% SL, its depth 5-6 % SL, 29-35 % its length.
-Coloration »Silvery, back brownish,; a roundish blackish spot beneath the first rays of the dorsal fin, which sometimes also are blackish; a crescent shaped band at the base of the caudal fin«. Countershaded.
Type locality
»Léopoldville«, Kinshasa (4° 15 ‘ S 15° 20 ‘ E), Democratic Republic of Congo.
Distribution
Congo basin.