The heaviest of the reef jacks, and it hunts by running fish into the shallows.
To about 170 cm and 80 kg, deep-bodied with a steep forehead, silver-grey to almost black, with scattered small dark spots on the flanks in some individuals. Large fish are noticeably blunt in profile compared with the bigeye and bluefin trevallies. Colour darkens sharply when hunting.
It hunts singly or in small groups, driving fish into shallow water and against the reef, and will follow larger animals — sharks, rays, monk seals elsewhere in its range — to take what they flush. It also takes crustaceans and cephalopods. Encounters are usually brief: the fish arrives fast, circles once, and leaves. It is not a resident of muck sites and is far more regular on current-swept outer reef. Recorded from the shallows to about 50 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.