Octopus Throws Shells and Debris Toward Its Neighbor in Anger

Scientists were astounded!

It was the first time they have ever seen octopuses throwing things at each other – shells, silt, debris, and algae. What’s more, they have been throwing things underwater, where such actions can be very difficult, even if you have eight arms!

“The throwing — or propelling or projecting — of objects that have been gathered and held is rare in the animal kingdom,” Peter Godfrey-Smith, a science philosopher at the University of Sydney in Australia and co-author of the study, told the Guardian’s Nicola Davis. “To propel an object, even for a short distance, underwater is especially unusual and also quite hard to do.”

The study was conducted in Jervis Bay, Australia — in areas that the scientists nicknamed “Octopolis” and “Octlantis” for their dense populations of octopuses.

Upon analysis of more than 24 hours of underwater video footage from the sites in 2015 and 2016, the researchers were astonished to find gloomy octopuses tossing shells, algae, and silt through the water, which, at times, managed to strike other octopuses.

The researchers recorded 102 instances of throwing among ten octopuses, with two females making 66 percent of the throws. This is a behavior observed among female octopuses when they feel harassed by male octopuses. Meanwhile, the scientists also noted that octopuses of both sexes with dark-colored skin appeared to throw more forcefully and were more likely to hit another member of their species. According to them, an octopus’s dark-colored skin is an expression of aggression.

But, what’s the real motivation behind octopuses’ throwing or projecting things underwater? Experts are not yet so certain. There were incidents in which the thrown things didn’t have any targets at all, and there were times that the objects were directed toward other octopuses, like a neighbor that they wanted to go away. Octopuses are loners, and it’s only because of habitat needs that they can be found living near each other.

Further, according to the researchers, more than 50% of the throws were done a couple of minutes after fighting or mating — and the things they usually threw were shells and algae. But when it comes to a hated neighbor, an octopus’s preferred weapon was silt!

Also, interestingly, a few octopuses that were cleaning their dens attempted to throw things at the stationary cameras that had been accidentally placed at a close range to their homes. Some of the throws missed, but there were a couple of hits!