Cephalopods have colour-changing chromatophores on their skin, which allows them to camouflage themselves — but the blue-ringed octopus has a different trick up its tentacle. Michelle Starr is ...

The small blue ring octopus is extremely venomous, with toxin 1,200 times more powerful than cyanide. Its bite can swiftly paralyze, potentially leading to death within 20 minutes. There is no known ...