Petrocephalus gliroides (Vinciguerra, 1897)
Species overview
Small fish, body rather short and deep, head moderately long, slightly longer than deep, snout short, about as long as diameter of eye, mouth inferior. Head with three aggregations, »rosettes«, of cutaneous sensory organs. Dorsal fin originating slightly posterior to origin of anal fin. Caudal peduncle short and deep. Back greyish, belly yellowish, countershaded, without any markings. Size observed: 150 mm SL.
P. gliroides(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 28-32 % SL; head depth 27-28 % SL, 80 % body depth.
-Outlines of back and belly slightly convex, upper profile and underside of head convex, bases of unpaired fins slightly curved, steeply running to caudal peduncle.
-Snout rounded, short, 16-17 % head length, 27-28 % postorbital length.
-Mouth 19-24 % head length, inferior, its edge below posterior rim of eye, upper jaw on a level with lower edge base of pectoral fin.
-Chin inconspicuous.
-Teeth notched, 11-14/20-24.
-Nostrils closely together, upright-oval, on a level with lower rim of the eye; axis parallel to axis of head.
-Eye diameter 20-26 % head length, up to 32 % postorbital length. Three rosettes, aggregations of electrorecpetors, on the head.
-Opercular cleft strongly curved, posterior border caudally to base of pectoral fin, 33-36 % head length, 38-41 % head depth.
-Dorsal fin 27-29 fin-rays, base of D 21-23 % SL, anal fin 28-33 rays, base of A 24-27 % SL, origin of D more or less opposite origin of A, end of D well before end of A; predorsal length 60-64 % SL, preanal length 58-64 % SL.
-Pectoral fin pointed, extending beyond middle of pelvic fin. V is closer to P than to A.
-Caudal fin pointed, scaled part short. 37-40 scales in lateral line; 12-14 round caudal peduncle.
-Caudal peduncle 16-20 % SL, its depth 8-9 % SL, 36-51 % its length. (Data in part after Whitehead and Greenwood, 1959).
-Coloration »Greyish above, yellowish beneath«, countershaded.
Type locality
»Fiume Ganana, Lugh (Somalia)« Lûq, Luuq, Somalia (3° 56 ‘ N 42° 32 ‘ E)
Distribution
Somalia.