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Home › Information Diving › Scuba Injuries › Octopus Bite

Blue-Ringed Octopus Treatment

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.

How Do Venomous Octopuses Bite Humans

Blue ringed octopuses inhabit the tidal pools and coastal reefs in areas of the western Indo Pacific Ocean countries, including:

• Australia (and New Zealand)
• Fiji
• Indonesia
• Japan
• Papua New Guinea
• The Philippines

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.

Octopuses Do Not Have Teeth

These large cephalopods don't have any teeth. But, they have a sharp beak and a radula used for biting, scraping, and chewing their preferred food source (e.g. clam shells, shrimps).

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:

• Cone snails (including the moon snail)
• Puffer fishes
• Poison dart frogs
• Rough-skinned newts

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.

Preventing Marine Life Envenomation

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:

• Blue-lined octopus (Hapalochlaena fasciata)
• Greater blue-ringed octopus (Hapalochlaena lunulata)
• Southern (or lesser) blue-ringed octopus (Hapalochlaena maculosa)

Pro Tip: Another section contains important information about passive interaction with aquatic animals, especially for beginners.

Blue-Ringed Octopus Bite Symptoms

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:

• Breathing difficulties (e.g. a tightness in the chest)
• Cyanosis (blue or purple tissue discoloration)
• Dizziness
• Dysphagia (difficult to swallow)
• Droopy eyelids
• Dysarthria (trouble with pronunciation)
• Headache
• Malaise and muscle weakness
• Numbness (around the mouth, face, tongue, and neck)
• Nausea and Vomiting
• Paresthesia (numbness, prickling, and tingling in the lips)
• Ptyalism (excessive salivation)
• Respiratory failure (may occur within 10 minutes)
• Severe hypoxia (insufficient oxygen in the blood)
• Small, painless bite which may become red and swollen (like a blood blister)
• Sweating
• Tremors and paralysis
• Visual disturbances

Severe Secondary Stages

• Progressive paralysis (first in the extremities, moving to the rest of the body, and ending in the respiratory muscles). This may lead to further breathing difficulties and dyspnea (shortness of breath)
• Cardiac dysrhythmias or arrhythmia (abnormal heart rhythms)
• Hypotension (abnormally low blood pressure)
• Mydriasis (fixed and dilated pupils)
• Coma, seizures, and respiratory arrest (resulting in death)

Important: If the dose of the nerve toxin is big enough, an untreated bite from a blue ringed octopus may cause death in humans.

Blue Ringed Octopus Bite Treatment

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:

• Clean the wound or injury site with freshwater and provide the appropriate care for treating a small puncture wound.
• Carry out the techniques for applying a pressure immobilisation wrap. Heat will not denature (alter) tetrodotoxin because it is a heat-stable toxin.
• Try to keep the victim still, quiet, and reassured. Do not let them walk around.
• Be vigilant for signs and symptoms of progressive paralysis and prepare to provide mechanical ventilations (e.g. with a bag valve mask device or a manually triggered ventilator).
• Without any necessary delay, seek professional medical care for an evaluation at the nearest emergency department.

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.

Special Considerations for Blue-Ringed Octopus Treatment

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.

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