Pollimyrus isidori fasciaticeps (Boulenger, 1920)
Species overview
Small fish, body short, rather deep, head as long as deep or slightly longer, snout rounded, clearly protruding mouth which is clearly subterminal; head with a V-shaped brighter marking, body silvery, densely dotted, countershaded, unpaired fins with dark markings on first rays, caudal with dark band on base. Size observed: 80 mm SL.
P. i. fasciaticeps(measurement)
Taxonomic description
-Body short and deep, strongly laterally compressed, body depth 27-39 % SL, greatest depth above pelvic fin or at origin of anal fin.
-Head length 23-34 % SL; head depth 19-31 % SL, 70-85 % body depth.
-Outline of back slightly convex, upper profile of head strongly convex, underside of head convex, outline of belly slightly convex, bases and anal of dorsal fin steeply running to caudal peduncle.
-Snout blunt, rounded to truncate, clearly protruding mouth, 14-23 % head length, 31-39 % postorbital length.
-Mouth 13-19 % head length, subterminal, its edge a line below posterior nostril, upper jaw on a level with lower edge base of pectoral fin.
-Chin inconspicuous.
-Teeth notched, 6-7/8.
-Nostrils separate, circular, anterior nostril on a level with lower rim of lens, posterior nostril on a level with lower rim of eye and very close to its anterior rim. Axis of nostrils cutting axis of head at an angle of about 30°.
-Eye diameter 16-27 % head length, 27-54 % postorbital length. Opercular cleft moderately curved, its posterior margin above base of pectoral fin. 22-35 % head length, 20-43 % head depth.
-Dorsal fin 18-19 fin-rays, base of D 18-24 % SL, anal fin 24-25 rays, base of A 25-28 % SL, origin of D well behind origin of A, end of D more or less opposite end of A; predorsal length 51-66 % SL, preanal length 50-59 % SL.
-Pectoral fin pointed, extending nearly to the tip of pelvic fin. V is closer to P than to A.
-Caudal fin obtusely pointed, the scaled lobes rounded and short. 38-50 scales in lateral line; 20 round caudal peduncle.
-Caudal peduncle 18-22% SL, its depth 4-9 % SL, 22-42 % its length.
-Coloration »Brown above, silvery beneath, finely dotted dark brown, like powdered; a V-shaped band on the head, with arms directed obliquely behind the eyes; a blackish spot on the bases of the anterior rays of dorsal and anal fin, and a bar of same colour at the base of the caudal fin«.
Type locality
P. fasciaticeps: »Léopoldville«, Kinshasa 4° 15 ‘ S 15° 20 ‘ E (Democratic Republic of Congo;
P. vanderbilti: »Fort Sibut; Ubangi-Shari« (Ubangi river: mouth: 0° 30 ‘ S 17° 42 ‘ E; boundary between Congo-Brazzaville and Democratic Republic of Congo).
Distribution
»Middle Congo basin« Republic of Congo-Brazzaville and Democratic Republic of Congo.