The big science question: why do octopuses pound their companion fish

Scientists have witnessed a strange fact - octopuses pound fish with tentacles, and they do this not at all for protection or hunting. The octopus sharply throws out a tentacle in the direction of the fish, as if beating it with a fist. At first glance, this unpleasant behavior seems to be the result of a direct interspecies conflict, but not everything is so simple. Scientists call it the "active suppression tactic" of fish, this occurs in the midst of a joint hunt, when octopuses and fish team up to stalk and catch prey together.

Octopus and fish hunt together and complement each other's strategies and strengths, explains marine biologist Eduardo Sampaio of the University of Lisbon. When several partners participate in the hunt, a complex network of interactions is created between individuals, which implies the emergence of hierarchy and control. Scientists compare this phenomenon to a crush in a school cafeteria, when an older student can afford to push a first grader in line for a bun.

Sampaio and his team observed the interaction of Octopus cyanea with various fish species in the Red Sea. The researchers concluded that punching punches served a specific purpose in interspecies relationships. Most of the blows go to maintaining the hierarchy during the hunt, whether it be scaring away prey, encouraging a change in position in the team, or even expulsion from the group. Sometimes a certain freeloader fish does not participate in the hunt and behaves like a parasite, hoping to reap the fruits of other people's labor - and in such cases the octopus also does not intend to put up with it.

Beating does not always happen for practical reasons. On two occasions, scientists observed strikes unrelated to attempts to secure prey. Sometimes it was just malicious behavior to wear down the fish and prevent it from getting close to the prey. It can also be a form of aggression with delayed gain, so that the partner fish behaves appropriately as they interact further, or with the aim of contributing to the overall microclimate in the group.