Shore Buddies Wisdom Wednesday
Photo by William Soo
The Mototi Octopus, also known as the greater blue-ringed octopus, is one of several species of blue-ringed octopuses. All are thought to be venomous and for their size, they are the most deadly of all cephalopods. This venom is more toxic than of any land animal. It is said that the venom of this octopus could kill 26 adults in just a few minutes. There is no antivenom for treatment. It has been confirmed that blue-ringed octopuses are immune to the venom of their own and that of other pygmy octopus. Fortunately, these octopuses do not attack humans. Injury typically occurs when a blue-ringed octopus is stepped on or picked up. These octopus are bottom dwellers inhabiting sandy and silty areas in shallow coral reefs, tidepools, and clumps of algae at depths of 0-20 m (0-66 ft).They hide in rock crevices, inside empty seashells, and in discarded bottles and cans. Greater blue-ringed octopuses have a soft sac-like body and eight sucker-covered arms. Their body background color at rest is usually tan to dark yellow, or occasionally gray. Up to 25 faint blue rings as large as 8 mm (0.3 in) in diameter cover the dorsal surface, mantle, and extend out over the arms. The center of each ring is usually a dark brown color. Each ring has a dark blurred edge, containing some of the chromatophores that cause color changes when the animal is stressed. At such a time the faint blue rings change to a brilliant iridescent blue that often seem to glow. A short blue line runs through the eyes. The body is often covered with papillae that give it a rough appearance. As blue-ringed octopus evolved, they partially lost their defensive ability to ink as their ink sac became smaller and smaller. Today’s juveniles can still ink but the ink sac greatly reduces in size as the octopus grows.