Octopuses have been observed occasionally hurling debris at each other especially when they are angry.
A team of researchers from the University of Sydney registered The behavior of a group of 10 common Sydney octopuses in Jervis Bay, New South Wales, Australia, over several days in 2015 and 2016, using underwater cameras.
Octopuses have been seen collecting slime, shells, and algae and pushing it through a jet of water emanating from their siphons.
Investigators discovered 102 cases. About half of the throws occurred during interactions with other octopuses, such as mating attempts, and about 17% of the thrown objects hit other octopuses.
The researchers say this indicates that octopuses are able to trigger targeted releases of other individuals – a behavior previously only seen in some animals.
Although it’s not clear why octopuses threw these items, the researchers noted that animals that changed their skin to darker colors — a behavior usually interpreted as a display of aggression — did so more often.
Lead researcher Professor Peter Godfrey-Smith, of the University of Sydney, said, citing Science Focus.
He added that “octopuses displaying a uniform, dark or medium color, fired more times at high power, while octopuses displaying dark, pale eyes fired more times at low power.”
The investigator concluded that “releases by octopuses that showed uniform body patterns, especially uniform dark patterns, struck other octopuses more often than other body patterns.”