ALL YOU EVER NEEDED TO KNOW ABOUT THE Blue-ringed octopus

BLUE-RINGED OCTOPUSES ARE a genus of small octopuses known for their iridescent blue markings. The patterns only reveal themselves when the creatures are disturbed or feel threatened.

- BY MELISSA HOBSON

This can lead to cases of mistaken identity when the animals are calm, they appear relatively harmless.

These octopuses hunt and defend themselves using their bite, which contains a highly toxic venom. This paralyses their prey so they can gobble it up, and can also be deadly to humans. Thankfully, bites are rare as blue-ringed octopuses aren’t aggressive.

Where do blue-ringed octopuses live and how big are they?

Found in the tropical waters of the Pacific and Indian Oceans, blue-ringed octopuses inhabit coral reefs, rocky areas of the sea bed and tidal pools. They are diminutive creatures, often fitting into the palm of your hand and weighing less than 100g. Sizes vary depending on the species, of which there may be around 10, though only four have been named. The largest is the southern blue-ringed octopus at 22cm, while the greater blue-ringed octopus is about 12cm long. In between are the blue-lined octopus and the extremely rare Hapalochlaena nierstraszi, of which only two specimens have ever been found, in 1938 and 2013. Little is known about the species, though the 1938 specimen had a 16cm-long mantle (head).

What adaptations do they have?