The shimmering clouds under jetties and in caves, and the reason predators come there.
Small slender fish to about 12 cm, translucent silver-green with a bright silver stripe along each flank and a large eye. Several genera and species are involved, they cannot be separated underwater, and this entry is pitched at the group rather than at a species — a photograph of a school will not settle which one it is.
Schools of thousands hold under jetties, in cave mouths and against shallow structure, moving as a single body and parting around a diver. They are the standing prey for trevallies, tuna, needlefish and lionfish, and a school that suddenly compresses or explodes is the usual first sign of a predator entering. Photographically they are the background rather than the subject: a diver inside a school with a wide lens gets the school, a predator cutting through it gets the picture. Recorded from the surface to about 15 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.