Blue-Ringed Octopus

blue-ringed octopus

Photos by Roy Caldwell

Blue-Ringed Octopus (aka Blue Ring Octopus) Facts

The only dangerous octopus in the world cruises the waters of Australia.
Fully grown these marine animals are usually smaller than your hand, 10-20cm (4-8″) in diameter with tentacles extended and a yellow/brown colour, perhaps with brown bands.
When angry brilliant blue rings appear on its body, though that may be too late to warn you or your children.
It’s often found near the shoreline or in rocky pools, hunting crabs.
If it’s picked up or trodden on it’ll bite with a little beak in the mid-underside of its body.
The bite may not be noticed immediately, but pain followed by severe breathing difficulties, nausea and paralysis will clarify matters soon enough.
Death is rare but not unknown.
The Blue-Ringed Octopus also releases venom into the water surrounding it.

Blue-ringed Octopus avoidance

Don’t touch, poke, play with or stand on any blobby animals near or on beach in Australia. Whether they are Jellyfish or Blue Rings they won’t do you any good!

Blue-ringed Octopus Bite Symptoms

Within ten minutes of the bite, nausea, vomiting, extreme pain, vision problems, numbness, muscular weakness, severe breathing difficulties, nausea and floppy paralysis.

Bite Treatment

• reassure the victim and keep him/her still.
• quickly wrap a light bandage above and below the bite (if you can’t get two fingers under the bandage, it’s too tight).
• Immobilize/splint the bitten area and keep it at heart level (gravity-neutral) if possible. Too high causes venom to travel to the heart, too low causes more swelling.
• Do not drink alcohol, or take any medicine or food.
• Take victim to medical facilities urgently.
• You may have to assist with mouth-mouth ventilation.

There is no known antivenom to the Blue-Ringed/Blue Ring Octopus.


The stonefish is found all over the world, including in cold European waters, but it’s more common and vicious in warm waters. The small, well-camouflaged stonefish snuggles under the sand in shallow water leaving poisonous spines sticking up ready for an unwary foot.


There are no safety measures you can take except wear some kind of sand shoes/sandals. You won’t see this dangerous animal till it’s too late.

Stonefish Sting Symptoms

Immediate excruciating pain, followed by swelling of the foot. Muscle weakness, paralysis and dying skin may follow.
The pain will subside after a day, though the swelling may take longer to disappear.
Not usually life threatening but a very unpleasant experience.

Treatment (the same for most stinging fish)

Immerse the area in hot water, take a pain killer and head for hospital.
A tetanus shot and X-rays may be needed to check for Stonefish spine fragments still in the victim. A more serious pain killer would probably be appreciated too!