A copper-coloured sweeper with a large eye, packed into caves and wrecks in dense schools by day.
To about 15 cm. Oblong, very deep and highly compressed with a near-horizontal back and a huge eye about a third of the head length, coppery red to olive with a silver sheen. Juveniles are semi-transparent.
The character is a dark band along the base of the anal fin, which separates it from the other Caribbean sweeper.
Two to thirty metres in clear water on coral reef. It packs into dark crevices, caves and the insides of wrecks in dense, slowly milling schools by day, which is how every diver meets it, and disperses at night to feed on zooplankton and larval invertebrates.
Common names in this genus are unstable — STRI calls this one the copper sweeper and gives “glassy sweeper” to a different species — so the scientific name is the thing to work from.
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.