Why do octopuses spray (throw) things at each other?

Octopuses in Australia throw gravel at each other, according to a new study that has not yet been peer-reviewed. © Courtesy of Peter Godfrey-Smith

Leviathan Press:

Remember this classic Pisces rant?

And this Spitting Leaders, created by Spanish artist Fernando Sánchez Castillo, truly reproduces the literal meaning of "spitting each other":

© De Gelderlander

Two octopuses were resting on a pile of shells in calm waters south of Sydney, Australia, when one of them, without warning, sprayed the other with a splatter of gunk in the face, sending it flying several inches away—like getting splattered on a sidewalk in New York City.

The scene was caught on camera. It's one of dozens of similar images showing octopuses spraying a stream of water carrying small debris. In a new preprint study based on the scene, the researchers say the behavior proves that octopuses do "throw" objects at each other. In one case, a female octopus repeatedly sprayed mud at her desired mate, the researchers wrote.

(www.biorxiv.org/content/10.1101/2021.08.18.456805v1.full)

Peter Godfrey-Smith, lead author of the study and professor of philosophy of science at the University of Sydney, said the observations were significant because directed throwing behaviour is rare in the animal kingdom. Elephants, monkeys and birds are among the few animals that have the ability to throw objects, but the skill is sometimes thought to be unique to humans.

An octopus pushes mud toward another octopus off southeastern Australia. © Courtesy of Peter Godfrey-Smith, David Scheel, Stephanie Chancellor, Stefan Linquist, and Matthew Lawrence

But some experts don't consider the behavior to be throwing, and question whether the animals are intentional. "If they were throwing, they would pick it up before throwing it," said Jennifer Mather, a renowned octopus expert at the University of Lethbridge in Canada. She was not involved in the research, but she suspects that the octopuses are simply spraying water toward potentially dangerous areas - a behavior we have discovered for decades. It's not a clearly social behavior, she said.

© Laughing Squid

In recent years, we've been completely fascinated by the intelligence of octopuses, drawing parallels between their behaviour and our own. It's hard not to be drawn to the idea that octopuses dream - or that male octopuses are rejected for their advances. But experts say we should be careful about how we interpret these findings, because octopuses are nothing like us. Ultimately, we shouldn't honor animals for their human-like qualities. It's precisely because they're different that they're so special.

Octopuses sometimes spray ink at researchers

Studying octopuses can be a chore. They have tube-like structures on their bodies, called siphons, that help them move around by draining water. But they also use their siphons to spray water or ink at anything that annoys them (including researchers). "They'll spray ink out of the water and stain your clothes," said Frank Grasso, an octopus researcher at the City University of New York.

Yes, octopuses in labs will poke out of the water and spray ink at unsuspecting researchers. Grasso's clothes have been soiled by them at least once, he said. "I've been sprayed hundreds of times by octopuses, and they target their targets," said Piero Amodio, an octopus researcher in Naples, Italy.

In one hilarious but valuable example that is a little hard to believe, Godfrey-Smith writes: "Octopuses have learned to disrupt electrical circuits by spraying water at light bulbs when no one is around."

Mather said that in the wild, the siphon of an octopus has many other functions, such as cleaning up debris and discarding food scraps in the cave. She said: "If the octopus is going to make a place to live, they will clean it up first. They will also spray water at scavenging fish that follow them."

Does all this mean that the octopus uses its siphon as a water gun and the debris as bullets?

Scientists collected a large number of octopus videos in a place called Octopolis in southeastern Australia. The animals there are surprisingly numerous and are generally considered antisocial. © Courtesy of Peter Godfrey-Smith

Do octopuses really throw objects at each other?

Octopuses are a difficult creature to spot in the wild—unless you’re in octopus capital.

Octopus Capital, named by Godfrey-Smith, is a small area off the southeastern coast of Australia that is home to a large population of the common Sydney octopus, also known as the melancholy octopus. Several cameras set up in the area gave researchers a rare glimpse into the interactions between these antisocial animals.

Video footage from Octopus City clearly shows some unusual siphoning behaviors: octopuses there store silt, algae or shells in their tentacles and then use siphons to discharge them several feet away, the researchers wrote.

A: An octopus sprays mud and algae at another octopus. B: Another octopus's face is covered in mud and algae. C, D: Detailed illustrations. © Peter Godfrey-Smith et al

Of course, Godfrey-Smith admits that "throwing" is not a good way to describe this behavior. "Technically," he said, "it's just a special way of propulsion that an octopus uses."

The researchers observed more than 100 instances of this behavior in less than 24 hours of footage starting in 2015. Typically, octopuses use their siphons to push objects out of their burrows or discard food scraps. But sometimes, they appear to fire fragments at specific targets.

Octopuses always seem to be able to target annoying people, is this intentional?

In more than a dozen cases, scientists have spotted octopuses attacking other octopuses with debris. The behavior is more common among females, says Godfrey-Smith, author of Other Minds: The Octopus, The Sea, and The Deep Origins of Consciousness: “It’s fascinating to see a female attack a male in this way multiple times over just a few hours until the male runs away.”

In another case, a male octopus turned pale in anger after his courtship was rejected, and his breathing seemed to quicken, and he threw a shell in a huff.

An octopus sprays mud at another octopus, which then ducks. © Courtesy of Peter Godfrey-Smith, David Scheel, Stephanie Chancellor, Stefan Linquist, and Matthew Lawrence

The octopuses also threw debris at other fish and underwater cameras that tried to get close to their burrows, the researchers wrote. They even moved toward their targets before throwing.

These behaviors suggest that octopuses have the ability to throw objects at a given target, perhaps to attack them. So octopuses definitely belong to the ranks of animals that regularly throw or push objects, but they cannot yet be included in the list of animals that have the ability to accurately throw objects.

The octopus carrying the shells to move around surprised many people. After all, compared with hermit crabs, this behavior of octopuses is more exposed and may bring more danger. © Totalwar.org

But Mather and many outside experts don't believe the octopuses actually pick up and throw debris. They think the octopuses may just accidentally hit one another while cleaning out their burrows.

Meanwhile, Amodio said it's possible that the octopuses were picking up debris with the intent to throw them, but certainly not purposefully. They probably just pushed the debris in the general direction of where the offending object was, he said.

Common octopus on the Costa Brava, Spain. © Reinhard Dirscherl/ullstein bild via Getty Image

For his part, Godfrey-Smith is having trouble figuring out whether the octopus's throwing behavior is intentional. Still, he's sure the octopus is aiming. You can't explain why the female octopus repeatedly hurled debris at the male. "Octopuses don't need to clean their nests that often," he says. And the male must have known he was being attacked because he ducked.

Why we care so much if octopuses throw things at each other

Regardless of whether the octopuses intentionally throw objects at a given target, or whether the behavior can be called "throwing," the study shows that octopuses can use their siphons to cleverly move debris, set up nests, and even send signals to other animals, including humans.

Does this mean they are smarter than we thought?

This question is fraught in itself because it underlies common notions of what intelligence is. In our assessments of the animal world, intelligence is often measured by human standards. As primatologist Frans de Waal puts it in Are We Smart Enough to Know How Smart Animals Are?, “Each species is able to adapt flexibly to its environment and to come up with solutions to the problems it presents, but in different ways.”

An octopus swims in the high seas off Hawaii. © David Fleetham/VW PICS/Universal Images Group via Getty Images

Octopuses bear little resemblance to us. In fact, as Elizabeth Preston wrote in The New York Times, “When the two branches of the animal lineage diverged, vertebrates had not yet emerged, so we should be very cautious in speculating about the mental workings of these animals.”

Experts say that exploring octopus intelligence is beneficial because we will have more respect and sympathy for them based on our further understanding, which is of great significance to the protection of wild animals. Mather said: "You don't want to protect something you don't respect."

However, the amazing thing about octopuses is not how different they are from us. For example, octopuses have eight tentacles, each with about 300 suckers, each of which has up to 10,000 sensory neurons, which give them a sense of touch and taste. "If you have these, you are not a human, you are an alien," Grasso said.

By Benji Jones

Translation/Sodium Potassium

Proofreading/Rabbit's Light Footsteps

Original article/www.vox.com/down-to-earth/22651130/octopus-launch-objects-behavior-intelligence

This article is based on the Creative Commons License (BY-NC) and is published by Sodium Potassium in Leviathan

The article only reflects the author's views and does not necessarily represent the position of Leviathan

Source: Leviathan