A slender blue and yellow open-water fish with two small finlets before the tail, which comes in to be cleaned.
To about 180 cm, commonly 80 to 90. Very elongate and near-cylindrical, much slimmer than any Caranx, with a pointed snout and a small mouth. Dark olive-blue above with two narrow pale blue stripes separated by a broader olive or yellow one.
The structural character settles it outright: a single detached two-rayed finlet behind both the dorsal and the anal fin. No other jack here has finlets at all.
Nought to a hundred and fifty metres, usually the top ten, over reefs and in open water near the surface around islands and offshore. It may form large schools and it gathers around floating debris. It eats planktonic crustaceans and small fish.
Divers often report it rubbing itself against sharks. That behaviour is not in any source consulted for this entry, so it is left as something people say rather than something this page states.
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.