Blue-ringed octopi are some of the deadliest marine life in the ocean, though they rarely bite humans.
There are several species of blue-ringed octopus, part of a genus known as Hapalochlaena. They live in tide pools in the Pacific Ocean between Australia and Japan and also out to the western Indo-Pacific islands — but you may also be exposed to them at an aquarium or other marine life organization.
Blue-ringed octopi are small in size: no larger than approximately 2.5 inches long, with arms that are about 4 inches long. Most of the time they’re yellow or sand-colored, but bright blue rings appear on their body when they’re about to strike.
They’ll strike only if they feel threatened. If a blue-ringed octopus does bite you, you need to get medical treatment immediately because their bites can be fatal in a short amount of time.
Blue-ringed octopi bites are lethal to humans because of the creatures’ venom.
The venom can kill more than 20 humans in just a few minutes, though this is extremely unlikely to happen. Blue-ringed octopi won’t bite unless they feel provoked. Plus, they generally stay hidden away during the day and are awake at night.
There have been very few reports of deaths from blue-ringed octopi bites in the last several decades. One 2008 study notes that there are just three human deaths on record.
Blue-ringed octopi have venom called tetrodotoxin, or TTX. This is one of the most serious and deadly types of venom found in the ocean. The octopi’s salivary glands produce the venom, and the bacteria gets dispersed through their beak.
TTX can paralyze a human in minutes. Due to this paralysis, your body wouldn’t be able to get enough oxygen, and death from a blue-ringed octopus would occur.
You might experience a range of symptoms if a blue-ringed octopus bites you. You may not actually feel the bite itself, but it’s imperative to get medical treatment right away if you suspect it occurred.
Symptoms of a blue-ringed octopus bite will progress rapidly in about 10 minutes.
Early symptoms of a blue-ringed octopus bite may include:
- excessive saliva production
- difficulty swallowing
- chest tightness
- lightheadedness and dizziness
- loss of vision
Symptoms can quickly get worse, escalating to:
- weakness in your muscles
- lack of coordination
- lack of oxygen in your tissues, resulting in discoloration that appears as blue or purple
A blue-ringed octopus bite is a true medical emergency because of how lethal its venom is. You should seek immediate medical attention if you’re bitten, even if you don’t suspect that the creature injected you with venom. There’s no antivenom for a blue-ringed octopus bite.
- supplemental oxygen
- intravenous (IV) fluids
- intubation (if you’re not able to breathe adequately on your own)
You’ll also want to care for the wound site. This involves cleaning the bite area with fresh water (not salt water). You should apply the pressure immobilization technique to the wound after it’s cleaned.
This involves wrapping an elastic bandage wrap (ACE bandage) over the wound site, then continuing to wrap it around the rest of that body part very tightly. Complete the treatment by splinting the wrapped area with something stable.
There’s little reason to fear getting stung by a blue-ringed octopus if you’re careful. Don’t prod one while you’re swimming or if you encounter one in another marine life environment, like an aquarium.
Blue-ringed octopi will bite only when they feel threatened. Try not to poke into small spaces in their natural habitats. They can move in and out of very tiny spaces, so be careful to avoid touching any object where they may hide.
The prognosis of a blue-ringed octopus bite depends on the timing in which you receive medical treatment.
Not all bites result in severe symptoms, but a healthcare professional should watch over you for several hours following a bite. This will allow them to treat potentially dangerous symptoms that may occur hours after the animal encounter.
If you’re able to get intubated and put on a ventilator in time, it’s possible to survive the bite.
In a 2008 study, for example, a 4-year-old boy survived a blue-ringed octopus bite. He received intubation and oxygen from a ventilator within 30 minutes of being bitten.
The paralysis from the venom began to wear off after 15 hours, and doctors removed the ventilator after 17 hours. The study reported that the child had no long-term complications from the bite.
A blue-ringed octopus bite is rare but extremely dangerous. Avoid disturbing the creatures in their habitat to lessen the risk of being bitten.
You need to seek immediate medical attention if a blue-ringed octopus does bite you. Quick interventions may save your life.