Even though humans have died from blue-ringed octopus bite, it is very rare. In fact, most people will survive after being bitten by a venomous cephalopod.
The information in this guide explains the typical signs and symptoms of envenomation and the recommended first aid treatment for blue ringed octopus bite.
Blue ringed octopuses inhabit the tidal pools and coastal reefs in areas of the western Indo Pacific Ocean countries, including:
They are small, rarely exceeding twenty centimetres (8 inches). But, they are extremely venomous. In fact, it's the only cephalopod known to endanger the lives of humans.
A mass of blue iridescent rings covering the yellowish body makes them easy to identify. But, they only display this feature when they feel threatened, while hunting, and during the mating rituals.
Pro Tip: The section about marine mollusks contains more octopus facts and information, such as what octopi eat and the reproductive process.
Scientific studies show that envenomation from a blue-ringed octopus is very rare. In almost all cases, professional medical intervention will result in a full recovery for the victim.
Here's the thing:
All cephalopods possess a very strong beak (similar to that of a parrot) and they all deploy a venom to paralyse its prey.
Yet, the powerful neurotoxin (tetrodotoxin) released when a blue ringed octopus bites another animal or human is around 10,000 times more potent than cyanide. Hence, the victim would be paralysed within a few minutes by the same neurotoxin that's also used by:
Pro Tip: Less than one milligram of the venom tetrodotoxin (TTX) from the octopus's salivary gland is enough to kill a human being. In fact, you can fit that tiny amount on the head of a pin.
Blue-ringed octopuses are mostly nocturnal creatures. As a result, they spend most of the daylight hidden in tide pools or shallow reefs.
There are only three (3) species, and none of them are aggressive around scuba divers or snorkelers:
Pro Tip: Another section contains important information about passive interaction with aquatic animals, especially for beginners.
In most cases, being bitten by a blue-ringed octopus is 'relatively' painless (similar to the sting from a bee). Even so, most of the serious injuries associated with scuba require an appropriate response.
The typical neurological symptoms that occur through initial stages of marine life envenomation, include:
Important: If the dose of the nerve toxin is big enough, an untreated bite from a blue ringed octopus may cause death in humans.
Layperson rescuers should accept the first aid treatment for blue ringed octopus sting management as being one that is 'supportive' because no antivenom exists. Follow these general steps if someone gets bitten:
Important: The actual bite site from a blue ringed octopus might still be lethally toxic even if the patient does not feel pain (imperceptible). Removing body tissue with a scalpel (e.g. wound excision) is not recommended.
If cardiopulmonary resuscitation (CPR) is required, it must be maintained until the diver begins to breathe (which may take several hours).
The pressure bandage must not occlude normal circulation. The fingers or toes beyond the bandage should remain pink with sufficient sensation. The bandage should be left in place until proper medical support is available.
Note: The short video [presented by National Geographic] contains stunning footage of the blue-ringed octopus subduing small fish and crabs, poisoning them with venom, and then eating them.