This species is distinguished by the following characters: body relatively deep and laterally compressed, greatest body depth 2.2-2.4 in SL; dorsal profile of head convex in adults, in oblique straight line in young; maxilla without scales or longitudinal ridges; preopercle with a deep notch (or gash) receiving elongate interopercular spine (for individuals of about 20 cm SL); gill rakers of first gill arch 37-42 + 71-81 = 110-122; soft rays of dorsal fin usually 13; continuous dorsal fin with spinous portion distinctly notched in young; dorsal and anal fins distinctly pointed posteriorly, the soft ray of both fins, shorter than next to last ray; caudal fin rounded (individuals < 20 cm SL) and emarginate (individuals >10 cm SL); pelvic fins very long and pointed in young, but short and rounded in adults; soft dorsal and anal fins with scales basally; tubed lateral-line scales 50-55; juveniles with very long pelvic fins. Colour of adults dark grey brown dorsally and shading to yellow on head and ventral body, head with fine blue lines or spots, body scales with blue lines or short dashes, smaller adult with trace or juvenile pattern especially the white spots; juveniles with distinct black and white pattern, with more than 5 white spots on back; subadult similar to juvenile but with white spots on back more numerous and black areas with small white spots (Ref 9821, 90102).