Scientists from the University of Sydney have found that octopuses can throw shells at each other: females usually do this when they want to stop too persistent courtship.
In 2015, scientists installed cameras on the east coast of Australia to monitor the life and habits of octopuses. With the help of them, they were able to record how the octopuses throw various objects.
True, this does not look like it does in humans: an octopus takes a shell, algae or debris from the bottom, then brings it to its siphon and directs a stream of water at it, which carries the object away. The distance of such a throw can reach several body lengths of the octopus itself. The octopus has only one siphon, it leads to the mantle cavity, where the mollusk is taken into the water. At the right moment, the muscles of the mantle cavity contract strongly, pushing out water – an impulse for movement is created.
Scientists previously thought this was common behavior and was needed when building a shelter or dumping food waste. But when more examples of such behavior accumulated, the researchers found out that octopuses throw an object at a specific target and, quite often, hit.
For example, during one of the observations, a female octopus threw objects ten times in a row at a male neighbor, who had previously tried to mate with her. There were cases when it did not come to a throw: the female lifted the shell, and the male had already managed to retire.
According to the authors of the work, the ability to purposefully throw objects is characteristic only of highly developed animals. Researchers continue to study the features of this behavior of octopuses in order to more accurately describe how and why they throw objects.