Octopus Engineering: Cephalopod's Squishy Tentacles Never get Tied Up

It might seem inevitable that an octopus would get tangled up in its squishy suction-like tentacles. Yet scientists know. There's a bit of engineering magic that prevents this cephalopod from getting bent out of shape.

"We were surprised that nobody before us had noticed this very robust and easy-to-detect phenomena," said co-first author Guy Levy, who carried out the research with Nir Nesher, via a press release. "We were entirely surprised by the brilliant and simple solution of the octopus to this potentially very complicated problem."

The secret behind an octopus's body motor control shows that they are not aware of their arms, unlike humans and other mammals.

"Our motor control system is based on a rather fixed representation of the motor and sensory systems in the brain in a format of maps that have body part coordinates," he adds, via the release. In other words, our bones keep us from dealing with this issue.

While studying severed octopus arms, researchers discovered that these sea creatures remain active for more than an hour after amputation. Their suckers are also actively able to continue holding onto other objects. 

The findings suggest that the octopus's skin contains a chemical extract that works as a repellent.

For instance, they found that the octopus's arms didn't grab petri dishes covered with octopus skin, but they did attach to dishes that were only partially covered with less force.

"The results so far show, and for the first time, that the skin of the octopus prevents octopus arms from attaching to each other or to themselves in a reflexive manner," the researchers noted, via the release. "The drastic reduction in the response to the skin crude extract suggests that a specific chemical signal in the skin mediates the inhibition of sucker grabbing."

In the future, researchers hope to use these traits to work with robotic designs. 

More information regarding the findings can be seen via the journal Current Biology.