Blue-Ringed Octopus Packs A Toxic Punch

Southeast Asia's blue-ringed octopus is small and cute, but don't touch one or you may wind up with a bite from one of the most venomous animals in the world. But don't worry... all you need is a ventilator to breathe for you for the next 15 hours, and you'll be good as new!

This tiny octopus, about the size of your hand, has a brownish yellow color that it uses to blend into rocks so it can ambush crabs. It carries the powerful tetrodotoxin in its saliva, the same toxin that pufferfish are famous for. It is thought that the toxin is made by microbes in the salivary glands, and then spreads out throughout the rest of the octopus's body, even making its way into the eggs, to discourage predation. Tetrodotoxin works by blocking sodium ion channels in the nervous system. Sodium ions act as signalling molecules by which the nerves communicate directions to muscles; when channels are blocked, paralysis occurs. Only a tiny amount of the toxin is enough to cause paralysis of the diaphragm, which controls lung expansion. One small blue-ringed octopus has enough to suffocate 10 or more people.

Postsynaptic response in the presence of tetrodotoxin is almost nonexistent.

Though the creatures are widespread, there are relatively few cases of bites to people, due to the octopus's shy and docile nature. However, the few unlucky ones that do get a bite are in for an ordeal. Though the small bite may even go unnoticed at first, after 10 minutes the victim's face and lips begin to go numb, and it becomes difficult to speak or call for help. Vomiting proceeds, and soon it becomes impossible to stand. Breathing becomes strained, and the numbness will take over the whole body. If they are brought to a hospital, no antidote is available; the only treatment is to hook the patient to a ventilator for around 15 hours or so, until muscles begin working again, including those of the lungs which allow for breathing.