
Big blue octopus
Octopus cyanea
Pinnoctopus macropus

The Atlantic white-spotted octopus is a striking, deep red hunter that comes out after dark to work its way through the coral, arm by arm.
Also known as: long-armed octopus, white-spotted octopus, grass octopus, grass scuttle, whitespotted octopus, longarmed octopus, whitespot octopus, white-spot octopus
It shares reefs with the common octopus, but hunts by night rather than day, and its first pair of arms is noticeably longer than the rest, unlike the common octopus's more even arms.
This octopus is red, marked with white blotches on the body and paired white spots along the arms. Its colour deepens and grows more intense when it feels threatened. The first pair of arms is much longer than the other three pairs, and a shallow web connects all the arms at the base.
It lives close to shore over sand, rubble, or seagrass meadows, sometimes burying itself under the sand by day. At night it moves from one coral head to another, wrapping its mantle around the branches and probing inside with its arms for hidden fish and invertebrates.
When this octopus works a coral head at night, groupers and other predatory fish often tag along, snapping up small animals that bolt out as the octopus searches the branches.
Describe what you saw and we name it, then keep every species you find in your Oceandex.