These creatures are generally found living in tidal regions from Australia to Japan, in the Pacific and Indian Oceans, amongst the coral reefs and tide pools. Possessing a large head and two big eyes, their glowing blue rings are a sign of feeling threatened and ready to attack. Should you spot one, do not provoke it, and stay clear of its path.
The blue-ringed octopus is said to hold two types of venom in its saliva: the ability to kill their prey with one type of toxin, whilst the other is used as defense. Primarily feeding on small crustaceans during the night, the octopus will wait until the venom has spread throughout their prey’s body before consuming.
Known as the only octopus that is poisonous to humans, most common blue-ringed octopi carry enough poison that can kill 26 adults, all within a few minutes.
Like most animals, the blue-ringed octopus will only attack if it feels threatened or is stepped on. Each year several people are bitten, however, their bite is rarely lethal. In most cases, when the victim is first bitten they are unaware of the octopus’ presence in the area.
Usually when a person is bitten they may not know about it; the bite is slight and will produce little to no discolouration of the skin (bite area), and no more than a tiny drop of blood. Although the bite is small, the victim will begin to feel the effects within 5 to 10 minutes: paresthesias, numbness, progressive muscular weakness, and difficulty in swallowing and breathing. Sometimes the victim further experiences nausea, visual disturbances, vomiting and difficulty speaking. When symptoms continue and worsen, unconsciousness occurs, with possibility of death following.
There is currently no antidote available for this venom, however, after about 15 hours the victim’s muscles will start working again. Usually those who survive the first 24 hours will make a complete recovery.
Although this is among the deadliest sea creature, only three deaths caused by the blue-ringed octopus have ever been reported – two in Australia and one in Singapore.