A heavy eastern Pacific triggerfish with an orange flank, turning over rubble to feed.
To 40 cm, commonly 30. Sharply two-toned: dark brown over the upper body and light brown to yellowish-orange on the head and lower side, which is the name. There is a thin oblique yellow bar running from the back corner of the mouth across the lower head, and narrow black stripes in the cheek grooves. The body is robust and compressed with leathery skin, regular diagonal scale plates and notched, powerful teeth. Juveniles have dark spots and broken lines on the upper body.
The finescale triggerfish is the confusion and is much larger and uniformly olive-grey, with no yellow cheek bar and no sharp division between a dark top and an orange lower side.
It lives on rocky reef between about 3 and 35 m, alone, feeding on the bottom. Like other triggerfish it wedges into a crevice and locks its first dorsal spine upright. At Revillagigedo, Galapagos, Cocos and Clipperton it is on all the 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.