Australia
Study shows: octopuses deliberately throw mussels and silt at other animals
An octopus throws objects around itself. The behavior was newly observed by researchers.
© University of Sydney
To date, throwing objects has been observed almost exclusively in mammals. A new study shows that octopuses also tend to hurl shells, silt and other objects.
Researchers have observed a special characteristic of common Sydney octopuses: They throw mud, mussels and algae around – specifically at conspecifics and fish. The behavior of the animals is extremely unusual for the researchers: “Throwing at other individuals of the same population, as is apparently observed in these squids, is a rare form of non-human projectile use previously only observed in a few social mammals.”
The behavior of the sea creatures was discovered on video recordings from Jervis Bay in the state of New South Wales. Although the videos are from 2015 and 2016, they have now been re-evaluated by scientists led by Peter Godfrey-Smith from the University of Sydney. Overall, the researchers found more than 100 cases in which the animals threw shells and silt around.
Animals collect material and then throw it around
The images show how the octopuses first collected the material and then flung it around them using their funnel organ. Normally, this funnel organ is used by squids for breathing and locomotion.
Since the animals had to put their funnel organ in an “unusual position” for the throws, the researchers assume that the actions were deliberate.
An image combo shows Sydney octopuses (Octopus tetricus) throwing around shells and silt. photo
© PLOS ONE/dpa
The researchers have not yet fully clarified what exactly the background to the litters is. On the previous video recordings, litters from females account for around two thirds of the “attacks”. It is also striking that a number of “throws” did not reach a goal.
Targeted throwing has so far been observed primarily in some monkey species (particularly chimpanzees and capuchin monkeys) and elephants.