Hunts in daylight, changes pattern several times a minute, and watches you back.
A substantial octopus with a mantle to about 16 cm and a total span approaching a metre, and the one most likely to be seen moving about in broad daylight. Colour and texture change continuously — mottled brown to brick red, smooth to heavily papillate, often with a dark false eyespot at the base of the second and third arms — and a hunting animal will pass through dozens of patterns in a minute.
Hunts by moving over rubble and reef and throwing the interbrachial web over a patch, feeling underneath it with the arm tips, then moving on; a diver following one at a polite distance can watch this repeatedly. Dens are marked by a midden of cracked crab and shell debris at the entrance, which is how a resident animal is located without seeing it. It is unusually attentive to divers, holding position and watching rather than withdrawing, which is where most of the popular writing about octopus intelligence starts. Recorded from the shallows to about 30 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.
