Protecting oneself by striking back at someone who harasses you can be called a natural human instinct. But scientists have found evidence of similar behaviour in octopuses. They have seen female octopuses try to fend off harassing males by throwing small pebbles, pieces of shell or other debris at them.

A recent study posted on the preprint server bioRxiv, which has not been peer reviewed, says camera footage showed the female octopuses gathering small pieces of material with their arms and propelling them at other octopuses with a strong jet of water.

Researchers including Peter Godfrey-Smith of the School of History and Philosophy of Science at the University of Sydney said some throws appeared to target others and to play a "social role". Some throws were launched differently, from under the arms, and these were more likely to hit another octopus.

Scientists have been observing this unusual behaviour off the east coast of Australia since 2015. Octopuses also use this knack for throwing when building their dens.

The study sorted a total of 101 throws into categories. Of these, 36 were in a "social context", and more than half were "partly social".

Social throws are mainly those that happened within two minutes of another octopus coming close. They were seen as apparent responses to fights between two octopuses, attempts to mate or other behaviour.

The study also found that of the 24 octopuses that threw material, 11 did so in a social context. However, none of the octopuses that were hit threw anything back or started a fight.

In 2016 a female octopus threw material at a neighbouring male 10 times, hitting him five times. The male, which had repeatedly tried to mate with her, only tried to dodge what was thrown at him and never struck back.

The report cites IANS and MSN.

Source: Jagonews24. First published in Bengali on The Agro News.