Blue-backed by day, red-backed at night, with a dark stripe down the middle of the back.
To about 30 cm, slender, blue-green above and silver-white below with a dark blue-black stripe running along the midline of the back and black tips to the tail lobes. At night and in resting fish the upper body turns red-brown, and a night diver finding one wedged in the reef will not match it to the daytime fish without knowing.
It schools in mid-water over slopes and drop-offs, often in mixed groups with other fusiliers, taking zooplankton. Schools of several hundred move fast and continuously and are the standing prey base for trevallies and mackerel. It is a species where the useful photograph is of the mass rather than the individual, and where a school reacting is a better subject than a school cruising. Recorded from about 3 to 45 m.
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.