Deep compressed body; a small mouth with brush-like teeth; preopercle with large spine at its angle, with vertical margin serrated; bone between preopercle and operculum with 1-4 large spines; bone under eye without large, rear-pointing spines; a single, un- notched dorsal fin, XIV, 17-18; anal rays III,17-18; dorsal and anal fins end in filaments; tail straight; lateral line weakly developed, ends under end of soft dorsal fin; large (45-48 in lateral series) regularly arranged, very rough scales with distinct ridges on the exposed part, scales extend out onto the median fins.
Blue-grey; whitish tail fin; a small (~ eye-sized) white spot on upper side above tip of pectoral fin; margins of dorsal, anal, and pelvic fins electric blue; juveniles grey-brown with about 7 narrow blue bars, including two on head.
