Also known as Blue Ring Octopus, Greater Blue-ringed Octopus.
Found singly in their burrows or foraging for food over mixed sand and rubble areas of bays, lagoons and rock-pools.
They feed on bivalves, crustaceans and small fish.
Depth of colour varies to blend in with surroundings their blue rings also vary, when alarmed they will show more and brighter rings to warn it's predators.
Length - 10cm
Depth - 0-20m
Widespread Indo-West Pacific
The Blue-ringed Octopus are highly venomous not only to their prey but also to humans. They inject their prey by biting with a powerful neurotoxin to paralyze, which then allows the octopus to devour its prey.
For humans this causes respiratory arrest!
Octopus make their homes in holes in the reef or bury in the sand.
They can often be found by the tell tail debris outside the holes.
Octopus feed by grabbing their prey with their tentacles or by spreading their skirt (the webbing between their tentacles) over the reef and hoovering up underneath.
They have a beak for biting their prey, the bite quickly paralyses their prey.
Some of the smaller Octopus are venomous to humans. Ref: https://en.wikipedia.org/wiki/Greater_blue-ringed_octopus