The brain of octopus is a lot simpler than that of humans. But until now, researchers have struggled to explain how these cephalopods coordinate their eight arms during complex crawling movements. According to a new study conducted by three Israeli scientists, octopuses move with simple elegance, but the problem behind this kind of movement is “not trivial.”
An octopus’ arms have a mind of their own
Israeli researchers led by Guy Levy of The Hebrew University of Jerusalem have revealed the secret of how octopus coordinates its flexible arms while crawling. The animal is bilateral symmetric, which means its right and left sides are mirror images of each other. But the brain doesn’t have to do everything because its arms have a mind of their own.
The brain of an octopus simply chooses which arm to use to move along. Researchers found that the animal has a preferred direction of movement. It moves at 45 degrees to the direction its eyes are facing. That angle provides a good view of its surroundings. Researchers found that octopuses can crawl in any direction without changing the position of their head. That’s because their arms are controlled independently of the head and body.
Nature’s solution to a complex problem
Dr. Levy said that by breaking the process in two parts, nature has found an amazing solution to a complex problem. Researchers said that the central nervous system of octopus makes only one decision: which arm to move. Then the actual movement of the arms is controlled by the peripheral nervous system. While its central nervous system has only 170 million neurons, the elaborate peripheral nervous system consists of about 330 million neurons.
It is the first detailed analysis of how octopuses manage to move even without a rigid skeleton. Findings of the study could be useful to engineers working to design biologically inspired robots. These animals crawl by shortening and elongating their arms, which gives a pushing thrust.
Findings of the study were published in the journal Current Biology.