Octopuses: knot to be messed with.

Octopuses: knot to be messed with.

Octopuses have evolved an ingenious way to avoid tying themselves up in knots, despite lacking full knowledge of what their arms are doing, researchers from the Hebrew University of Jerusalem have shown.

The hundreds of suckers lining the creature’s tentacles will stick to almost anything – but not the octopus itself, scientists have found.

They believe a chemical signal in the cephalopod’s skin prevents self-adhesion.

Without it, the flexible animals would quickly wind up in a tangle.

“We were surprised that nobody before us had noticed this very robust and easy-to-detect phenomena,” said Hebrew University researcher Dr Guy Levy.

Unlike animals with rigid skeletons, octopuses never know exactly where their arms are at any given moment.

Professor Binyamin Hochner, who led the Hebrew University team, said: “Our motor control system is based on a rather fixed representation of the motor and sensory systems in the brain in a formant of maps that have body part co-ordinates.

“It is hard to envisage similar mechanisms to function in the octopus brain because its very long and flexible arms have an infinite number of degrees of freedom. Therefore, using such maps would have been tremendously difficult for the octopus, and maybe even impossible.”