Caught On Camera: Octopuses Throwing Debris At One Another [Watch]

Octopuses are intelligent and rather enigmatic creatures. A team of researchers has caught octopuses appearing to deliberately "throw" silt and other objects around them, sometimes even at other octopuses.

The researchers caught the behavior from wild gloomy octopuses (Octopus tetricus) at a site in Jervis Bay, Australia, they wrote in their study, published Wednesday in the journal PLOS (Public Library of Science) ONE.

The reason it's interesting is that throwing is said to be rather "uncommon" in animals. Throwing while aiming at a target has been observed in other animals such as capuchins, mongooses, birds and even elephants, the researchers said, but the behavior has sometimes been considered to be "distinctly human."

In the case of octopuses, they are actually quite "anti-social." They tend to hunt alone, get into fights and even cannibalize each other. And now, apparently, they may be added to the list of creatures that throw debris around.

"Here we provide the first report for any octopus species of a behavior frequently seen at these aggregations: the throwing or projection of debris, both in social interactions and in other contexts," the researchers wrote.

In the video shared by Science X, one can see some of the throwing instances that the researchers captured. In it, the octopuses can be seen throwing silt and other debris around them, hitting other octopuses in what appears to be deliberate throws.

"In some cases, the target octopus raised an arm up between itself and the thrower, just before the throw, perhaps in recognition of the imminent act," the study's lead author, Peter Godfrey-Smith of the University of Sydney, said in the university news release.

The researchers gathered data from 2015 to 2016 using underwater cameras, collecting 102 instances of throwing among 10 octopuses, PLOS noted in a news release. They observed the creatures throwing materials to clean out their dens, hurling silt at the cameras and even at other fish.

Out of the throwing incidents they logged, 33% (17) were interactive in context.

"Throws that hit another octopus tended to differ in several ways from throws that did not," the researchers wrote. "These differences collectively suggest a degree of targeting."

While both male and female octopuses were observed to throw, females did it more often, accounting for 66% of the throws. One female, for instance, "repeatedly" hurled silt at a male that was trying to mate with her, according to the University of Sydney. The male had to duck to avoid the hits.

"Throwing at other individuals in the same population, as apparently seen in these octopuses, is a rare form of nonhuman projectile use, previously seen only in some social mammals," the researchers explained.

The octopuses did it by gathering the material in their arms, holding it in their arms and web, then using their siphon to project the material away in behaviors that may be interpreted as "throws."

But why were the octopuses "throwing"? The creatures' intentions are not quite easy to determine, Godfrey-Smith said, as per the University of Sydney.

For instance, it could be their way of establishing personal space, since the area they live in is rather cramped, though Godfrey-Smith noted this to be still "speculation." The behavior also didn't appear to start fights, as the octopuses did not appear to "return fire." Further, not a lot of the throws seemed to be targeting others.

That said, the observations do show wild octopuses engaging in throwing behavior, showing yet again just how intelligent these creatures might be.

"Even if no intention to hit other octopuses lies behind these throws, they do have social effects in interactions between individuals at this site," the researchers wrote. "Octopuses can thus definitely be added to the short list of animals who throw or propel objects, and provisionally added to the shorter list of those who direct their throws on other animals."