Scientists say octopuses punch uncooperative fish when they are together on group hunts.

• Octopuses punch fish to keep them in line during group hunts. When a fish doesn’t cooperate or tries to steal prey, the octopus punches it as a way to assert control and maintain order.
• Fish and octopuses benefit from hunting together. Fish act as scouts, while the octopuses act as leaders and keep the group organized.
• Octopuses use their arms to explore cracks and crevices fish cannot reach. And the fish eat prey that escapes from the octopuses.

Octopuses punch unruly fish on group hunts

Scientists have observed octopuses and fish hunting together across the globe. These different species cooperate in order to pull food from difficult-to-reach sources. But there’s definitely a hierarchy, the University of Konstanz said on September 17, 2024, with octopuses punching fish that get out of line.

Lead author Eduardo Sampaio of the Max Plank Institute of Animal Behavior and team published their study in the peer-reviewed Nature Ecology and Evolution on September 23, 2024.

Watching interspecies cooperation

Eduardo Sampaio and his team have observed and filmed octopuses hunting in concert with fish in Israel, Egypt and Australia. Their hours of footage have helped them learn how octopuses and fish work together to find food. Fish guide the octopus to the prey, and then the octopus uses its flexible arms to reach in and grab the cowering meal. And different fish can play different roles. For instance, goatfish scout and explore the area, leading others along, but the octopus is in charge of the timing and initiation of group movement.

In fact, you could say the octopus is the leader of the hunt. When a fish gets out of line, the octopus will dart out an arm at the fish, punching it and propelling it away. In most animal groups, the leader is the animal that more literal leads the group forward on hunts, etc. But in this situation, the octopus leads the group by directing the behavior of others.

The scientists used the term “partner control mechanisms” as a euphemism for when an octopus punches a fish that gets out of line. The scientists also found that octopuses were much more likely to punch blacktip grouper versus a blue goatfish. Sampaio said:

These results broaden our understanding of leadership and sociality, emphasizing the complexity and adaptability of social interactions in nature.

How they all benefit

This unique look at interspecies collaboration shows how they can benefit from each other. The octopus benefits by finding prey more easily, and the fish benefit by catching what the octopus doesn’t. Sampaio said:

This beneficial interaction enables fish to acquire otherwise unreachable prey, and octopuses to conserve energy by focusing on high-quality food sources, while exerting control and providing feedback within the group, highlighting the sophisticated dynamics of marine life collaboration.

Sampaio also said:

When the octopus catches the prey it also kills it. One item of prey is not divided, it is taken by whoever catches the prey first! However, because the interaction between the fish and octopus repeat several times during a hunt, prey is ‘shared’ in the sense that sometimes the octopus catches the prey, and other times fish catch the prey.

Bottom line: Scientists studying hours of footage of octopuses and fish hunting together found that octopuses punch the uncooperative fish and are the leaders of the hunt.

Source: Multidimensional social influence drives leadership and composition-dependent success in octopus–fish hunting groups

Via Max Planck Institute of Animal Behavior

Via University of Konstanz

Read more: Watch an octopus get spiky