Australian experts have discovered female octopuses have a habit rarely seen in animals that enables them to ward off unwanted male advances.
Octopuses have devised a clever tactic to ward off unwanted sexual attention, opting to “throw” shells and silt at males that are harassing them.
Researchers at the University of Sydney have been recording octopuses in Jervis Bay on the south coast of New South Wales since 2015.
After studying footage, they found that female octopuses would intentionally throw shells and silt and algae at male octopuses making unwanted mating advances.
The study, aptly titled “In the Line of Fire: Debris Throwing by Wild Octopuses”, determined octopuses frequently hit their targets with a “jet-propelled throw”.
While the males could perform the technique, it was more commonly performed by the females, largely during mating attempts – though the experts noted throwing away discarded remains of a meal and den maintenance also prompted use of the octopuses strong throw.
Peter Godfrey-Smith at the University of Sydney explained the cameras captured fights, matings and an extraordinary behaviour at the site in dubbed “Octopolis”.
“It’s hard to know how best to describe it,” said Godfrey-Smith told New Scientist.
When performed, the octopuses hold their chosen object under their bodies in their tentacles, then angle their siphons and shoot a jet of water at the projectiles, propelling them up to several body lengths.
When the study began in 2015, the team weren’t sure whether the octopuses were intentionally hitting others or if it was just an accident.
Now after analysing more footage, Godfrey-Smith and the team have determined the behaviour is definitely deliberate.
The behaviour of one female in 2016 became particularly compelling for Godfrey-Smith, after watching her throw silt 10 times at a male from a nearby den who was attempting to mate with her. She hit him on five occasions.
“That sequence was one of the ones that convinced me [it was intentional],” he said.
While the bloke tried to swerve the flying object, he wasn’t always successful.
The study also notes it is rare for animals to throw objects, especially at members of their own species.