When you’ve spent time in the sea, it’s always worth checking that you haven’t come ashore with any aquatic hitch-hikers. The advice is particularly relevant to underwater litter-collectors in the Indo-Pacific region.
An Australian snorkeller can count himself especially lucky, after finding that he had inadvertently brought home one of the world’s most venomous marine creatures.
Matt Rogerson of the Snorkelling Western Australia group had been doing his regular good deed collecting underwater rubbish at Perth’s North Beach before returning home to rinse out his rash-vest and wetsuit. That was when he noticed a blue ringed octopus crawling out from among his snorkelling gear.
“Didn’t feel a bite, but now read the bite is painless,” he posted on social media. “I took it back to a groyne with seaweed and set it free.”
Rogerson reckoned that the octopus had emerged either from a retrieved snorkel or a rubber dog’s ball with a hole in it, because the other litter he had collected would have provided no hiding places.
Divers know to treat blue-ringed octopuses with caution. Four confirmed species are found in the Pacific and Indian Oceans, growing no longer than 20cm, and their venom contains tetrodotoxin, which is also found in pufferfish.
They carry enough to kill as many as 26 people. A bite is likely to occur only if the octopus feels threatened, which is when it displays its blue rings, but it can take effect within minutes, causing total paralysis with the possibility of heart and lung failure.
No antidote is available, but bite victims can be saved if artificial respiration can be applied quickly enough, followed by treatment in hospital on a ventilator.
Despite the potential danger, the number of recorded fatalities remains relatively low. Nevertheless, “I'll be far more careful what I tuck into my wetsuit in future,” commented the fortunately unscathed snorkeller.