Scientists have discovered that female octopuses fling silt, shells, and algae at approaching males to deter them from seeking to mate with them.
The odd behavior of the eight-legged marine animals was seen on video at Octopolis in Jervis Bay, off the coast of New South Wales, Australia.
Apart from humans, only a few species have been discovered to hurl projectiles at other members of their own species, including chimps.
However, octopuses’ method of hurling things at intruding neighbors is brilliant, as it makes use of their powerful siphon, which can spew water at high speeds.
They have learned to repurpose their siphon and blast a jet of water at an object they clamp between two of their tentacles, which they generally utilize for a speed burst while hunting or to avoid predators.
The projectiles are usually held between the two forward-facing tentacles, although cephalopods have occasionally used various tentacle combinations to help them aim. They’ve honed this procedure to the point that they can shoot missiles several body lengths away and into the desired target.
The researchers discovered that two females executed two-thirds of the 102 recorded throws, and that females threw projectiles nine times as often as men.
The researchers from the University of Sydney wrote in their work, which was released as a pre-print on bioRxiv, that “throwing in general is more commonly witnessed by females, and we have seen only one hit (a marginal one) from a throw by a male.”
Other females in close dens and males attempting to mate with a female thrower were among the octopuses hit.
The recordings were made over the course of two months, in January 2015 and December the following year. When an octopus was hunting another octopus, the scientists discovered that silt, rather than shells or algae, was the weapon of choice.
When it came to all elements of octopus behavior, however, shells were the most popular choice.
The researchers discovered that when another octopus was the target, the throws were also more powerful. Low vigour throws were the most prevalent, accounting for 48 of the 102 throws in total. However, a third – 12 of 36 – were high vitality in social situations.