Grey-brown with fine blue lines and a pale bar at the tail base. Separated from the doctorfish by the absence of body bars.
To about 35 or 38 cm, commonly 25, and it lives to at least thirty-two years. A grey-brown to yellowish-brown oval disc. The mark is a set of yellow lines radiating back from the rear edge of the eye, sitting in a bluish patch, and there are no vertical body bars at all. The fins have light blue or white margins, there is a pale bar across the base of the tail, and the tail itself is crescent-shaped with a narrow whitish or yellowish rear edge.
The doctorfish is the constant companion and the check is the same one from the other side: no bars and yellow eye lines here, ten vertical bars there.
It grazes reef and adjacent seagrass and forms large mixed schools with the doctorfish and the blue tang to overrun damselfish territories. It is routinely seen in 2 m of water and has been recorded to over 100 m; treat it as a shallow fish to about 25 m.
The name is worth a note. This is the northern Caribbean species, separated in 2011 from a Brazilian species that used to carry the same name. For Florida, the Bahamas and Cayman this name is correct. The split is not perfectly clean — the Brazilian species has since been found in Cuba and Mexico — but the northern name is the right one here.
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.