There may be an octopus arms race underway. And that's not even a joke about tentacles: Octopuses are actually fighting, and potentially using weapons.
The creatures are hardly team players under the best of circumstances.
"Octopuses in general are regarded as fairly solitary animals," says Peter Godfrey-Smith, a marine biologist at the City University of New York. He is studying octopuses in Australia's Jervis Bay — specifically, the common Sydney octopus, also known as the gloomy octopus.
"A particular group of them have started living in higher concentrations than usual, which we think is because of some peculiarities of the site where they live," he tells NPR's Arun Rath. "And essentially, they've had to, we think, learn to get on a little bit. They've had to learn to interact, more than octopuses normally have to do."
And, well, there's been some friction. The octopuses in the bay have been fighting — or "boxing," as Godfrey-Smith calls it — and some have even been bullying others.
"There seems to be a lot of fairly ornery behavior which has to do with policing and guarding territory," he says.
But it gets worse.
Those ornery octopuses have also taken to hurling objects at each other, like shells and bits of seaweed, blasting them through the water with high pressure. And while Godfrey-Smith says there may be other explanations for this behavior, the number of direct hits has him suspecting that the octopuses are using projectile weapons.
"It would be quite significant if it's happening," says Godfrey-Smith, who's been collaborating on this research with David Scheel of Alaska Pacific University. "In general, projectile use is pretty rare among animals."
He says they've got a lot more observing to do before coming to firm conclusions about the shell-chuckers. In the meantime, he refuses to be baited by sensationalizing reporters.
"The prospects for octopus takeover are still fairly remote at present," he says.
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