Deep compressed body; a small mouth with brush-like teeth; preopercle with large spine at its angle, with vertical margin smooth; bone between preopercle and operculum without spines; bone under eye without large, rear-pointing spines; a single, un- notched dorsal fin, XI, 24-25; anal rays III, 20-22; dorsal and anal fins usually end in filaments; tail straight; lateral line complete; scales of variable sizes, very rough, with distinct ridges on the exposed part, scales extend out onto the median fins.
Grey, darker at front; rear of body and adjacent dorsal and anal fins charcoal or blackish; a broad yellow bar just behind margin of cheek, a second narrower yellow bar bordered with black just behind pectoral fin base; tail fin pale yellowish; juvenile black with six curved yellow bars on head, body, and tail with narrow blue bars between them.
Size: to 50 cm.
Habitat: usually seen solitarily or in pairs on rocky reefs. Juveniles "clean" parasites from the surface of other fishes.
Depth: 1-50 m.
Southern Baja and Gulf of California to Peru, including all the oceanic islands.