Octopuses are marine creatures with eight arms, each lined with hundreds of suction cups. These suckers allow them to interact with their environment and also possess chemoreceptors, enabling them to “taste” what they touch.
The Initial Grip
When an octopus makes contact, the sensation is often described as a gentle suction and a slight pulling. The numerous suckers lining an octopus’s arms are muscular structures designed for adhesion. Each sucker creates suction by contracting internal muscles, forming a low-pressure area, similar to a vacuum, against a surface. This mechanism allows octopuses to hold onto prey, navigate diverse terrains, and even cling to humans.
The outer, flexible ring of a sucker molds to the object’s surface, creating a watertight seal, while the inner muscles then contract to generate the strong grip. While the suckers themselves do not typically cause pain, the cumulative pressure from many suckers, especially from a larger octopus, can feel uncomfortable or leave temporary marks.
Understanding the Risks
While many octopus encounters are harmless, certain risks are associated with their grip, particularly with larger species. A significant octopus can exert considerable strength, capable of leaving bruising or temporary indentations on the skin. This strength can also lead to entanglement, where a large octopus might wrap its arms around a person, potentially restricting movement or pulling them into deeper water, posing a drowning risk.
A more serious concern is the possibility of a bite. Octopuses possess a sharp, parrot-like beak located where their arms converge. While most octopus bites are not venomous to humans, some species, like the blue-ringed octopus (genus Hapalochlaena), carry a potent and potentially fatal neurotoxin called tetrodotoxin. The bite from a blue-ringed octopus is often painless, and victims may not realize they have been envenomated until symptoms like numbness, muscle weakness, and respiratory paralysis begin to manifest. This neurotoxin can lead to respiratory failure and be fatal within minutes.
What to Do if it Happens
If an octopus grabs you, remain calm and avoid panicking. Sudden, forceful pulling can make the octopus tighten its grip, as its suckers are designed to resist such forces. Instead, gently peel the suckers away one by one, starting from the edges of the octopus’s arms. You can also attempt to push the octopus’s body away from the center of its suckers, or target its mantle (the main body sac) or beak area, as these are sensitive spots.
Moving slowly and deliberately can encourage the octopus to release its hold. Octopuses often let go once their curiosity is satisfied or if they are dislodged from an anchor point.
Should a bite occur, especially if you suspect a venomous species like the blue-ringed octopus, seek immediate medical attention. There is no antivenom for blue-ringed octopus venom, so medical treatment focuses on supportive care, which may include artificial ventilation until the toxin’s effects wear off. Applying a pressure immobilization bandage to the bitten limb can help slow the spread of the venom while awaiting professional medical help.