Lifespan Typically lives for about two years. The blue-ringed octopus, as deadly as it is said to be, is actually very small.

Deep-sea creatures often look more like science fiction monsters than marine animals. The glass octopus is one such animal.

Mr Gilchrist said the octopus's only used its venom as a 'last line of defence'. 'While these small octopus are one of the most dangerous species, bites to humans are rare,' he said. ' ...