The juvenile is yellow with black bars and swims alongside anything large, including divers.
Adults reach about 120 cm and are silver with a few dark blotches on the flank and yellow fins; they have no teeth, and feed by extending the mouth into sand to draw out molluscs and worms. Juveniles are bright yellow with seven or eight black bars and are the stage most divers meet.
Juveniles pilot alongside sharks, rays, large groupers and jellyfish, holding station just ahead of or beside the host, and readily transfer that behaviour to a diver — a small golden trevally swimming a few centimetres from a dome port for a whole dive is a common experience on muck sites. The behaviour is protective and opportunistic rather than a partnership. Adults form loose schools over sand. Recorded from about 2 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.