Petrocephalus catostoma congicus David and Poll, 1937
Species overview
Small fish, body deep, head shorter than body depth, longer than deep; snout blunt, short but longer than diameter of eye; mouth inferior; eye rather small. One aggregation, »rosette«, of cutaneous sensory organs on the neck. Caudal peduncle slender. Grey with darker head back and belly, without particular markings. Size observed: 76 mm SL.
P. cat. congicus(measurements)
Taxonomic description
-Body moderately short and deep, strongly laterally compressed, body depth 31 % SL, greatest depth between ventral and anal fin.
-Head length 26-27 % SL; head depth 24 % SL, 75-77 % body depth.
-Outline of back slightly convex, more than slightly convex outline of belly, upper profile and underside of head convex; base of unpaired fins steeply running to caudal peduncle.
-Snout short, bluntly rounded, 15-17 % head length, 25-27 % postorbital length.
-Mouth width 22 % head length, inferior, its edge below posterior rim of eye, upper jaw on a level with lower edge of base of pectoral fin.
-Chin inconspicuous.
-Teeth notched, 11/20-24.
-Nostrils closely together, upright-oval, on a level with lower rim of lens; axis parallel axis of head.
-Eye diameter 12-14 % head length, 21-23 % postorbital length. Only one rosette, an aggregation of electrorecpetors, above opercular cleft clearly to be seen. Opercular cleft strongly curved, its posterior margin behind base of pectoral fin, 37-44 % head length, 41-49 % head depth.
-Dorsal fin 18-19 fin-rays, base of D 17-19 % SL, anal fin 25-28 rays, base of A 24 % SL, origin of D behind origin of A, end of D slightly before end of A; predorsal length 61-62 % SL, preanal length 55-57 % SL.
-Pectoral fin pointed, extending to base of pelvic fin. V is closer to P than to A.
-Caudal fin pointed, scaled part short. 34-37 scales in lateral line; 12 round caudal peduncle.
-Caudal peduncle 20-21 % SL, its depth 5-7 % SL, 26-29 % its length.
-Coloration »Light grey, somewhat darker on head, back and belly«.
Type locality
»Mukishi (Lomami)« Democratic Republic of Congo (0° 46 ‘ N 24° 16 ‘ E).
Distribution
Congo basin, Haut-Zaïre, Democratic Republic of Congo.