Description: D 10-13 (usually 11-13); A 7-10 (usually 8-9); P I,12-16 (usually I. 13-15); predorsal scales 21-30 (usually 24-26); scales in an oblique (antrorse) row between the origin of the dorsal fin and the lateral line 6½-10½ (usually 8–8½); number of gill rakers 19-26 (4-8 + 14-19) (usually 21-24 (5-7 + 16-18); total vertebrae 38-43 (24-28 + 13-17), usually 40-41 (25-26 + 14-16); snout short, the upper jaw not pointed anteriorly; lower jaw shorter than upper jaw or of equal length (sometimes lower jaw slightly longer); jaw teeth small to medium (not visible to barely visible with naked eyes), mostly tricuspid and with additional cusps (some fish also with conical teeth); juveniles < 7.5-10.0 cm SL with mostly conical teeth; teeth arranged in 2-5 rows, in juveniles in 1-3 rows; palatine teeth always present, usually numerous (sparse in juveniles < 4.0-6.0 cm SL) (Ref. 130199).

It is a highly polymorphic, polytypic species with at least four subspecies within C. oligolepis, differ in pelvic-fin length, number of dorsal-fin rays, predorsal scales, transverse scales and vertebrae, pigmentation, and other characters (Ref. 130199).