Hovers in small groups above shallow reef and signals with colour changes down the body. It approaches divers rather than fleeing, which is unusual for a squid.
Mantle to about 12 cm, total length about 20 cm. A torpedo body with fins running almost its whole length, finely mottled brown above and pale below.
It is the only squid regularly seen by divers over inshore Caribbean reef, so there is nothing to separate it from.
Surface to a hundred and fifty metres. It moves in schools of four to thirty and spends about two-thirds of daylight resting, with sentinels posted. What makes it worth watching is the signalling: it has at least forty distinct body patterns and can display a different one on each flank at the same time, so a squid facing a rival on one side and a mate on the other is saying two things at once.
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.
