Octopuses can 'walk' on two legs

Octopuses can 'walk' on two legs

Two little species of Indian Ocean octopus can tuck up six of
their arms while running on the other two, U.S. researchers
reported on Thursday.

They can use their other six arms to disguise themselves from
predators, either as rolling coconuts or clumps of floating
algae, the team at the University of California Berkeley and
Universitas Sam Ratulangi in North Sulawesi, Indonesia found.

The discovery, published in Friday's issue of the journal
Science, discredits theories that walking requires hard bones and
skeletal muscle, as octopuses have neither.

"We have observed octopuses that do indeed walk," Berkeley's
Christine Huffard and colleagues write in their report.

"Individuals of Octopus marginatus (from Indonesia) and
Octopus (Abdopus) aculeatus (from Australia) move bipedally along
sand using a rolling gait," they added.

"This locomotion differs from their normal crawling, which
usually involves several arms sprawling around the body, using
the suckers to push and pull the animal along."

The researchers have videotaped the animals, one the size of a
walnut and the other the size of an apple, "walking."

Walking on two legs, or arms, makes sense for an octopus,
Huffard's team said.

"When an octopus moves quickly, it becomes visually
conspicuous and must employ unique behaviors to evade its
predator's search image," they wrote.

"By walking, both O. marginatus and O. aculeatus are able to
move quickly while using six of their arms to remain disguised:
O. marginatus perhaps as a rolling coconut and O. aculeatus as a
clump of algae tiptoeing away." --Reuters