Octopuses seen hunting together with fish in rare video — and punching fish that don't cooperate

A new study shows that some members of the species Octopus cyanea maraud around the seafloor in hunting groups with fish, which sometimes include several fish species at once.

The research, published in the journal Nature on Monday, even suggests that the famously intelligent animals organized the hunting groups’ decisions, including what they should prey upon.

What’s more, the researchers witnessed the cephalopod species — often called the big blue or day octopus — punching companion fish, apparently to keep them on task and contributing to the collective effort.

...

These hunting groups typically included several species of reef fish, such as grouper and goatfish. The octopuses did not appear to lead the groups, but they did punch at fish to enforce social order — most often at blacktip groupers.

“The ones that get more punched are the main exploiters of the group. These are the ambush predators, the ones that don’t move, don’t look for prey,” Sampaio said.

Octopuses would also punch fish to keep the group moving.

“If the group is very still and everyone is around the octopus, it starts punching, but if the group is moving along the habitat, this means that they’re looking for prey, so the octopus is happy. It doesn’t punch anyone,” Sampaio said.