When fish and octopuses hunt together, who leads? The one throwing punches, video shows

Mutually beneficial relationships help keep the animal kingdom in harmony.

Plover birds walk into the dangerous mouths of crocodiles and feed on decomposing meat inside, keeping the birds full and the sharp teeth healthy.

Woolly bats roost in carnivorous pitcher plants despite their reputation for dissolving creatures in their digestive juices. The bat stays near the rim and gets a safe place to hide, while the plant can feed on the excrement dropping into its equivalent of a stomach.

In reefs of the Red Sea and Australian Pacific Coast, researchers have now discovered that not only are octopuses living harmoniously with some fish species, but they are also working together to hunt prey.

Using diving gear and modified underwater cameras , experts from the Cluster of Excellence Collective Behavior at the University of Konstanz and the Max Planck Institute of Animal Behavior, in Germany, jumped into the water on the search for octopuses, according to a study published Sept. 23 in the peer-reviewed journal Nature Ecology & Evolution.

“The team operates the two cameras they have with them, and station many more to collect data. Then, it’s time to wait ,” according to a Sept. 23 news release from the University of Konstanz.

Over many months, researchers collected more than 100 hours of underwater footage off the coast of Israel, Egypt and Australia, the university said.

What researchers saw in the footage were groups of fish swimming around on the search for prey, followed closely by an octopus, according to the study.

When the fish identified prey, they would flag it in some way and the octopus would jump into action, using “its flexible arms to capture the hidden prey,” researchers said.

“In groups of Octopus cyanea and various fish species, social influence is not evenly distributed but rather hierarchically structured across multiple dimensions, reflecting specialized roles within the group,” study author Eduardo Sampaio said in the release.

For example, while a goatfish was responsible for exploring the area and choosing a direction, the octopus was responsible for the group’s timing and movement, according to the study.

The relationship is symbiotic — fish reach prey they couldn’t get to without the octopus’ arms, and octopuses don’t have to spend the energy to find food on their own.

But every group has to have a leader, and researchers found the octopuses are in charge.

Some fish would dart toward other fish in what was described as “partner regulation mechanisms in the form of aggressive actions,” according to the study.

Octopuses, on the other hand, would “displace fish by punching them,” researchers said.

“Punching involves an explosive motion of one arm directed at a specific hunting partner,” according to the study. “Across species, we found that the octopus was the main interspecific regulator of the group, perpetrating a disproportionate number of aggressive actions towards fish partners while receiving none, thus emerging as the most dominant individual.”

Researchers said though the hunting strategy is mutually beneficial, octopuses are able to keep potential “exploiters” in check with a swift punch, “reinforcing its position as the de facto leader” and making sure the octopus benefits from the relationship.

Octopuses are typically solitary animals, researchers said, so this behavior “exhibits remarkable social competence and cognitive flexibility” as the octopuses adapt their “behavior in response to the actions of different species.”

The researchers collected video from the Great Barrier Reef of the northern Pacific Coast of Australia and in the Red Sea, off the southern tip of Israel and the eastern coast of Egypt.

The study’s authors include Sampaio, Vivek H. Sridhar, Fritz A. Francisco, Máté Nagy, Ada Sacchi, Ariana Strandburg-Peshkin, Paul Nührenberg, Rui Rosa, Iain D. Couzin and Simon Gingins.

Dozens of sea creatures seen glowing for the first time. See the vibrant ocean animals

Fierce battle between octopus and seal stuns scuba diver off Canada. See ‘rare’ video