The blue-ringed octopus (genus Hapalochlaena) is normally found in the Great Barrier Reef and other coastal waters and tide pools around Australia and other Western Pacific islands. Though not an aggressive animal, when it does bite, such as stepped upon, it can inject tetrodotoxin along with a number of other toxic compounds.
Tetrodotoxin can cause paralysis, leading to respiratory failure and death, though the blockage of voltage-gated fast sodium channel conduction, blocking peripheral nerve conduction. Treatment is supportive, as the venom usually wears off within 4 to 10 hours.
