How some ways can an octopus flex its supple arms? Now we all know

By David Chandler

WOODS HOLE, Mass. — Octopus arms are one of the versatile buildings identified in all the organic world. Their agility is so extraordinary that robotics researchers need to be taught the secrets and techniques behind their actions, hoping to use a few of the identical rules. They envision comfortable, versatile robotic appendages that, just like the extremely tactile octopus arms, can search and perform duties by tight and slim openings, akin to delivering life-saving meals and water to folks trapped within the rubble of collapsed buildings.

Now, researchers from the Marine Biological Laboratory (MBL) in Woods Hole and Florida Atlantic University (FAU) have printed essentially the most detailed research ever of the advanced motions of octopus arms. They videorecorded 25 octopuses of their pure habitats, in six completely different places within the Atlantic, Caribbean, and in Spain, and developed a scientific catalog of their vary of arm actions as associated to behaviors, akin to foraging and locomotion. The findings are reported this week within the journal Nature Scientific Reports

“I’ve been trying for a long time to work out the natural behavior of cephalopods in their natural habitat,” stated MBL Senior Scientist Roger Hanlon, in whose lab the brand new research was carried out. This research represents the primary full ethogram, or detailed catalog, of octopus arm behaviors within the wild, and builds on earlier work by Hanlon’s group that studied octopus arm actions in tanks in his lab.

“Studying and recording octopus behavior from wild octopuses in the field gave us the opportunity to analyze a larger behavioral repertoire and further understand how they use their arms to achieve such complex behaviors,”  stated FAU analysis fellow and first creator Chelsea Bennice.

Octopus gardens

Octopus habits is guided way more by sensory organs of their arm suckers than by eyesight, Hanlon stated. “The octopus is a very tactile animal – it’s more tactile than visual.”

They are additionally extraordinarily good at camouflage, dynamically altering their pores and skin colour and texture to mix in with their setting. So, simply discovering them within the first place, as a way to document their habits, was an actual problem.

For essentially the most half, group divers Hanlon and Bennice would discover the animal’s habitat first (octopuses are messy eaters and sometimes depart meals particles round their hidey-holes). Then they’d await the octopus to return and monitor its exercise throughout the next days. Octopuses spend about 80 p.c of their time of their dens, solely rising a few times a day to forage for meals.

“I’m a strong believer that you have to get into the natural world, and especially the sensory world, of whatever animal you study,” Hanlon stated – and he’s been diving to check octopuses for over 25 years.

The six octopus habitats on this research various from easy, sandy seafloor to extremely advanced coral reef environments.

“The fieldwork is very arduous, and it takes a lot of luck to get valid natural behaviors,” Hanlon stated.

Breaking it down

The group went by its area footage second-by-second to catalog not solely each movement of every of the 25 octopuses’ eight arms, however to divide every arm into three sections and doc these actions individually.

Study co-author Kendra Buresch of MBL says that is the primary time the complete vary of 12 various kinds of octopus arm actions has been catalogued.

“These are the actions that make up the whole complex of octopus behaviors,” she stated.

Among the brand new findings is that, whereas all elements of the octopus arm are able to a full vary of various motions, some occur extra in a single arm half than one other. Elongation and shortening motions happen principally on the arm’s base, for instance, whereas bending happens principally on the tip.

The arms can carry out quite a lot of duties, from locomotion – “walking” throughout the seafloor or swimming above it – to probing reef crannies looking for prey, to manipulating objects.

In addition to their excessive flexibility, every arm has ~100 suckers that comprise extremely delicate sensory organs.

“Each sucker is a chemo-tactile genius,” Hanlon says, “the equivalent of the human nose, lips and tongue all wrapped into one.”

The analysis was partly funded by the U.S. Office of Naval Research, which hopes to develop robotic arms which have each nice flexibility and sensory capabilities.

After a submersible or a constructing collapses, “How do you deliver a drug or a phone or water to someone who’s down there?” Hanlon stated. “You need some snaky little arm with high flexibility that can not only get down there, but can do something useful when it arrives.”

—###—

The Marine Biological Laboratory (MBL) is devoted to scientific discovery – exploring elementary biology, understanding marine biodiversity and the setting, and informing the human situation by analysis and training. Founded in Woods Hole, Massachusetts in 1888, the MBL is a non-public, nonprofit