Scientists Figure Out Why Octopus Punch Fish On Hunting Parties

Marine biologists have known for a long time that certain species of octopus punch fish. Octopus cyanea are a species of octopus that typically live solitary lives except for when they embark on inter-species hunting parties with blue goatfish and grouper.

It is this species of octopus which is best-known to punch fish and marine biologists recently published a new study in the journal nature ecology & evolution about this behavior. The study, titled ‘Multidimensional social influence drives leadership and composition-dependent success in octopus–fish hunting groups,’ explains why octopus punch fish and the answer is a lot cooler than we ever expected.

Here’s what one of these cross-species hunting parties look like with an octopus and fish:

Putting on our critical thinking hat for a moment, let’s wonder why octopuses might display this behavior… The obvious answer is ‘to protect themselves’ and that’s what most marine biologists have assumed led to this behavior.

This new study, however, suggests that on these cross-species hunting parties octopuses are punching fish in order to enforce the roles and rules and when fish get punched it’s because they were trying to cheat the other members of the hunting party.

Here is what it looks like when a fish catches hands from an octopus (at the :20 mark):

The researchers behind this study sought to learn about “hunting groups of otherwise-solitary Octopus cyanea and multiple fish species, to unravel hidden mechanisms of leadership and associated dynamics in functional nature and complexity, when divergence is maximized.” They point out that most research done is species-specific and rarely focuses on cross-species interactions like these octopus-fish hunting groups.

What they found when looking at these fish-octopus hunting groups is the species take on specific roles. The fish is the goatfish “drive environmental exploration” and direct where the hunting group goes and when they travel. The octopus takes on the classic leadership role.

And here’s where it gets really cool… As the leader of these hunting parties, octopuses exhibit displays of “partner control mechanisms” which is a fancy way of saying “punching fish.”

So when the fish are getting out of line, maybe trying to eat more than their fair share or overstep the respected boundaries of the hunting party they catch a punch from their leader, the octopus. Researchers write “these findings expand our current understanding of what leadership is and what sociality is.”

There are SO MANY videos on YouTube about ‘octopus punches fish to defend itself.’ Videos like this one:

It’s high time to change the titles of those videos to ‘octopus is the boss and keeps fish in line.’ And a big shout out to the BBC’s Discover Wildlife for sharing this topic first!