Octopuses Trick Foes With 'Walk'

(AP)  Octopuses, known for using camouflage to avoid predators, have been observed apparently trying to sneak away by walking on two arms while pretending to be a bunch of algae.

Two kinds of octopus were seen to use different ways of walking along the sea floor, researchers were reporting in Friday's issue of the journal Science.

The movements were discovered by Christine L. Huffard of the University of California, Berkeley, who was studying underwater video camera tapes of the animals. Researchers filed the video showing one octopus curled up like a ball and walking on two "legs" and another apparently posing like a plant before strutting away here.

Berkeley professor Robert J. Full said Huffard was studying octopus movement as part of a robotics project. He said the researchers use examples from nature in designing robots; one project is to build a soft robot.

Octopuses trying to avoid being eaten usually hold still to camouflage themselves. But by walking on two arms, these two types were able to move quickly while using their other arms to disguise themselves.

Two individuals of O. marginatus from Indonesia wrapped six arms around themselves, looking like a coconut on the sea floor. They ten used the two rear arms to move backward.

In Australia, O. aculeatus was seen raising two arms above its head before lifting four more and moving backward on the two remaining arms. The researchers described it as looking like "a clump of algae tiptoeing away."

The researchers believe the octopuses were trying to flee from predators, though they cannot be sure until they have seen more examples of the behavior.

The research was funded by the American Malacological Society and the National Science Foundation.

By Randolph E. Schmid
By Randolph E. Schmid