Octopuses are leaders of fish, but it seems they’d rather be feared than loved. New observations of underwater hunting behavior reveal that these creatures use corporal punishment to maintain order among their minions, using their many arms to punch at fish, even though the fish are ostensibly their allies.
Many animals engage in cross-species cooperation when it comes to hunting. Despite octopuses generally being seen as solitary creatures, recent research has revealed they often form partnerships to hunt. Rather than team up with other octopuses, however, they team up with several different types of fish. Marine biologists are now gaining a clearer understanding of these relationship dynamics, and while no one is looking to fry and eat these fish, their octopus leader might be more inclined to give them a swift nudge.
Scientists have uncovered the secrets of multispecies hunting! Octopuses & fish team up, with fish guiding the hunt and octopuses capturing hidden prey. #UniKonstanz @CBehav+@MPI_animalbehav research reveals incredible interspecies teamwork. @NatureEcoEvo https://t.co/9xafHNQsv9 pic.twitter.com/c0vPiX094C
— Universität Konstanz (@UniKonstanz) September 23, 2024
The marine biologists, led by Eduardo Sampaio from Portugal’s Marine and Environmental Sciences Centre at the University of Lisbon, conducted scuba expeditions in 2018. During these dives, they observed several hunting groups made up of octopuses and various types of fish, including goatfish and different species of grouper. The octopuses and fish were bonded by a shared diet of small crustaceans, other fish species, and molluscs. They have evolved a mutually beneficial relationship in which each different type of animal plays a role in hunting. It’s a relationship that’s worked out swimmingly for both parties.
In the ensuing study, published in Nature Ecology & Evolution, Sampaio described several octopuses using their fish buddies as scouting parties. As a result, the octopuses knew where to find food, and would use their arms to pry open shells or reach into crevices to flush out potential meals. In turn, the fish were able to scavenge on the leftovers or attack the prey animals flushed from their hiding spots.
While this dynamic showed the octopuses weren’t dictators, they were still largely in charge, and would use violence to get their way. The punches, which the biologists defined as an “explosive motion of one arm directed at a specific hunting partner,” would result in the attacked fish being exiled towards the outer portion of the group.
In video taken by the biologists during one of their research dives, an octopus can be seen nestled on the seafloor. When a blackfish grouper, identified as part of the octopuses’ hunting team, swam up to one, the octopus extended an arm and gave it a quick whack, sending the fish scurrying away.
Octopuses getting pugilistic isn’t anything new. A 2021 study, which Sampaio also worked on, documented other examples of the eight-armed creatures hunting in collaboration with various fish species. Again, octopuses were seen punching some of their underwater neighbors. While it’s impossible to know what cephalopods are thinking, the biologists came up with two theories for why an octopus would lash out in situations where there’s no immediate benefit. The blow could be a way to promote collaborative behavior by punishing a fish for misbehaving during a hunt. Or, they wrote, it’s possible the octopuses hit a fish for no reason other than spite.
The new study built on that research, further delving into the complexities of the cross-species relationships. Goatfish, for example, were great at scouting spots with potential prey. The octopuses ultimately had the final say on whether the group would move and when. While the octopuses would strike out to maintain order, no fish ever made an aggressive move toward the leaders. The fish did, however, sometimes display similar behavior toward each other. Sampaio wrote in the new paper that fish would occasionally dart at one another, forcing their companions to move in a manner similar to the octopus punch.
This all makes octopuses sound like the eldest sibling in an unruly family. Maybe we shouldn’t be looking at them as beloved teachers, and more like the noogie-giving bullies who our parents put in charge while they ran errands.
