Spend a few minutes watching the graceful dance of an octopus on the tree and you will quickly appreciate the talent for making the arms flow like living liquid.
One thing that surprises them is their versatility. To test their motor skills, researchers from the Massachusetts Marine Biology Laboratory placed ten samples in their own tanks that were distributed specifically for filming every turn of their limbs.
In total, 120 minutes of images collected over several months included 16,563 arm deformations from 10 octopuses, providing ample examples of almost all types of bends, clockwise turns, imaginary turning, shortening and imaginary stretching.
We can easily accept that octopus levels are high among animals for ability, better performing the boneless movements found in worm torsos, elephant stems, and even our own twisted tongues. .
But in science, there are assumptions for cumps. Hard data are important, and surprisingly no one had mapped the detailed movements of octopus arms.
O. bimaculoides extending an arm to study its environment. (Michael LaBarbera)
We already have a good awareness of octopus anatomy and physiology. Each arm is essentially a string of nerves extending down from its own specific brain center, enabling members to make individual decisions according to their specific sensory system.
In fact, two-thirds of octopus neurons are transmitted through its eight arms in this way, resulting in more ‘brains’ in its borders than in any one central location. A fully flexed transverse muscle surrounds the axial nerve cord of each arm, which is connected by a fold of long-sided muscles with a fiber that runs far down the limb.
Sticky strips of oblique muscle fiber are intersected by these longitudinal, square muscles in two directions to provide torsion in a clockwise and counterclockwise direction. Finally, there is still another set of muscles, with the most fleshy part towards the base of the arm.
This complex arrangement of musculature means that octopuses have the ability to perform four types of movement – bending (in and out of the mouth), two torsion directions, elongation, and shortening.
To show exactly what types of movements each octopus arm can make, ten California wild two-spotted octopuses (Octopus bimaculoides) were captured and stored in glass aquariums at a marine biological laboratory.
Some tanks allowed the animals to move freely. Others had clear obstacles with a small hole – just big enough to push one or two arms through.
Then there were the tanks with screens that had a bunch of holes, some of which allowed the subjects to reach out to various textiles or food items.
Each location encouraged different types of movement, with several cameras set up to capture the full range of movements of each member where possible.
Check it out for yourself in the clip below.
Using the variable distances between suckers as a guide, the team measured the different movements used by each particular arm, down their length.
All sections of the limbs twisted clockwise and counterclockwise, for example, with no real preference for one side of the other, ruling out any real ‘hand’ in arm rotation.
However, the samples appeared to show preference in arms when it came to reaching out, with the two pairs of ‘front’ arms extending far more frequently than the two pairs of ‘back’ arms. .
“Even our research team, which is well versed in octopuses, was amazed at the sheer flexibility of each of the eight arms as we analyzed the frame-by-frame videos,” said a lead researcher. and cephalopod expert Roger Hanlon, an evolutionary biologist from the University of Chicago.
These amazing molluscs also deserve a blue ribbon when it comes to contortion; we could use their bodies for inspiration in the development of technology that scrapes and worms its way to cracks.
“These detailed analyzes can help guide the next step in determining neural control and coordination of octopus arms, and could find design principles that encourage the creation of next-generation soft robots. , “said Hanlon.
Imagine soft robots that go through collapsed buildings looking for victims, or even self-driving tubes that slide safely down a patient’s windpipe with the rigors of a hunting bark. octopus.
It is a dance that we can add more value now that we truly know that no other animal is like it.
This research was published in Scientific Reports.