Pollimyrus marchei (Sauvage, 1879)
Species overview
Medium-sized fish, body moderately elongate and deep, head rather short, slightly longer than deep, snout rounded, slightly protruding mouth. Caudal peduncle slender. Dark on the back, silvery beneath, countershaded; head and belly speckled brown.
Size observed: 184 mm SL.
P. marchei(measurements)
Taxonomic description
-Body moderately elongate, strongly laterally compressed, moderately deep, body depth 25-29 % SL, greatest depth between pelvic and anal fin or near the latter.
-Head length 21-25 % SL; head depth 18-22 % SL, 71-76 % body depth.
-Outline of back slightly convex, upper profile of head strongly convex, underside of head concave, outline of belly slightly convex. Bases of unpaired fins running moderately steep to caudal peduncle.
-Snout blunt, rounded, 19-24 % head length, 30-40 % postorbital length.
-Mouth 13-17 % head length, subterminal, its edge below anterior rim of the eye, i. e. below posterior nostril, upper jaw on a level between base of pectoral fin and underside of head.
-Chin inconspicuous.
-Teeth truncate or feebly notched, 5-8/6-8.
-Nostrils separate, anterior nostril on a level with lower rim of lens, posterior nostril oval, closer to the margin of the eye than to anterior nostril, on a level with lower rim of the eye. Axis of nostrils cutting axis of head at an angle of about 40-45°.
-Eye diameter 13-18 % head length, 21-29 % postorbital length.
-Opercular cleft curved, 25-40 % head length, 29-46 % head depth.
-Dorsal fin 22-24 fin-rays, base of D 19-21 % SL, anal fin 30-31 rays, base of A 26-29 % SL, origin of D well behind origin of A, end of D well before end of A; predorsal length 57-62 % SL, preanal length 50-56 % SL.
-Pectoral fin pointed, extending to tip of pelvic fin. V is much closer to P than to A.
-Caudal fin pointed, rather long, the scaled part obtusely pointed, about 1/3 the length of the membranous part. 57-62 scales in lateral line; 12 round caudal peduncle.
-Caudal peduncle 19-26 % SL, its depth 4-5 % SL, 18-26 % its length.
-Coloration »Olive-brown above, silvery beneath: head speckled with brown«. Countershaded.
Type locality
»Doumé, riv. Ogôoué (Congo français)«, Gabon. (Type locality seems questionable, there is no »Doumé« on the Ogowe, but instead a place »Booué«, which seems to be more likely.
Distribution
Rivers Ogowe (0° 49 ‘ S 9° 00 ‘ E) and Ivindo 0° 09' S 12° 09' E) and tributaries, Gabon; quite abundant.
Electric organ discharges
P. marchei(elec. organ)
P. marchei(EOD)