Petrocephalus simus Sauvage, 1879
Species overview
Small fish, body moderately short, deep, head slightly longer than deep, snout short, less than diameter of eye, mouth inferior. Head with three aggregations, »rosettes«, of cutaneous sensory organs. Caudal peduncle moderately deep. Silvery, countershaded.
Size observed: 107 mm SL.
P. simus(measurements)
Taxonomic description
-Body moderately short and deep, strongly laterally compressed, body depth 33-36 % SL, greatest depth at origin of anal fin.
-Head length 24-29 % SL; head depth 22-27 % SL, 67-82 % body depth.
-Outline of back slightly convex, upper profile of head and underside of head convex, outline of belly slightly convex, bases of unpaired fins steeply running to caudal peduncle.
-Snout rounded, short, 14-20 % head length, 22-33 % postorbital length.
-Mouth 18-22 % head length, inferior, its edge below posterior rim of lens, upper jaw on a level with lower edge base of pectoral fin or slightly above.
-Chin inconspicuous.
-Teeth notched 6-10/12-16.
-Nostrils closely together, upright-oval, on a level with lower rim of lens; axis parallel to axis of head.
-Eye diameter 20-28 % head length, 33-46 % postorbital length. Three rosettes, aggregations of electrorecpetors, on the head.
-Opercular cleft strongly curved 39-48 % head length, 41-51 % head depth.
-Dorsal fin 22-27 fin-rays, base of D 20-23 % SL, anal fin 27-33 rays, base of A 26-31 % SL, origin of D well behind origin of A, end of D well before end of A; predorsal length 59-64 % SL, preanal length 56-60 % SL.
-Pectoral fin pointed, length, extending nearly to the tip of pelvic fin. V is well closer to P than to A.
-Caudal fin pointed, scaled part short. 42-48 scales in lateral line; 12 round caudal peduncle.
-Caudal peduncle 14-20% SL, its depth 6-7 % SL, 30-43 % its length. (Data based on types and specimens of the Natural History Museum, London, synonyms not taken into account.)
-Coloration »Uniform silvery«.
Type locality
»Doumé, Ogôoué«. Cameroon (4° 14 ‘ N 13° 27 ‘ E).
Distribution
Liberia, Cameroon, Rep. Congo-Brazzaville, Democratic Republic of Congo.