From neon-green poison dart frogs to monarch butterflies, some of nature’s flashiest creatures have evolved vibrant ways of telling potential predators: “don’t mess with me.” Such is the case with this vividly colored blue-ringed octopus, filmed off the coast of Kiama, New South Wales, Australia.
When the cephalopods are agitated or threatened, iridescent blue rings flash across their entire bodies, an evolutionarily courteous warning to those who might see the octopus as their next meal. Or in the case of humans, attract curious onlookers. (Related: Watch Blue-Ringed Octopus Pounces on Unsuspecting Crab)
There are at least 10 species of blue-ringed octopuses, ranging from Japan to Australia. Smaller species like the blue-lined octopus are found mostly in shallow waters, leading to increased interaction with humans looking to enjoy the same places.
Despite its small and squishy stature, Hapalochlaena fasciata is one of the ocean’s most venomous creatures, capable of gravely injuring and even killing humans with just one bite. Their saliva contains tetrodotoxin, a powerful nerve toxin that causes respiratory failure. At least three deaths in Australia have been attributed to blue-ringed octopuses. (Related: "Octopus Chokes Dolphin to Death in First-Ever Discovery")
That doesn’t mean that humans should fear them, however.
“Like most animals, they will only attack a human if they feel like their lives are in danger. It is always out of self-defense rather than aggression,” says oceanographer Jenny Hofmeister. “Most bites come from people collecting what they think is an empty shell, put it in their pocket, and the octopus hiding in the shell comes out. This is why it is not recommended to shell-collect in areas where blue ring octopuses occur.”
While it may be tempting to follow bright and shiny creatures, it’s best to just keep your distance and let them go on their way.