The common eastern Pacific butterflyfish, pale with dark bands, usually in pairs over rock.
To about 25 cm, common at 12. White or silvery-white with a prominent black bar at the level of the pectoral fin, another just before the tail base, and a dark band running from the throat through the eye to the nape, with black markings on the dorsal, anal and tail fins.
At Revillagigedo the two black body bars on a white ground are diagnostic. The species STRI lists as similar are not eastern Pacific fish, so there is no local confusion species in the literature.
Three to fifty-five metres, commonest between five and twelve, on rocky ground near shore, in pairs or small groups, and monogamous. Adults eat algae and bottom invertebrates. It is not a coral feeder, which is part of why it does well on the bare rock of these islands.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.