診断 |
Diagnosis: distal margin of dorsal fin concave; body depth 1.9-3.0x SL; depth of caudal peduncle 0.8-1.2x its length; 24-42 (50-150mm) and 41-44 (150-250mm) gill rakers; scale formula 4.5-5.5/33-38/6.5; 3-4 scales between lateral line and pelvic-fin base; 12-16 scales around caudal peduncle; 9-10 dorsal fin branched rays (Ref. 2940, 81282).
Description: body rather elongate; snout prominent and tuberculate; two pairs of rather short barbels; all specimens examined had 12 scales around caudal peduncle, except for populations from Ogun (14 and sometimes even 16 scales); dorsal fin with concave distal margin in adults and showing allometric growth, the longest ray growing proportionally faster than head length; D:III,(9)10; A:III,5; P:16-17; V:I,8 (Ref. 2940, 81282).
Coloration: back blackish or greyish-green, belly whitish; dark longitudinal band along middle of sides from gill cover to end of caudal peduncle, bordered in live specimens by light yellowish bands; fins tinged with yellowish-pink; the above colour pattern is characteristic for juveniles or medium-sized individuals; pale bands bordering dark mid-lateral band tend to disappear after death, as well as in large individuals which are more uniformly colored on sides (Ref. 2940, 81282). |