Octopuses don’t always hunt alone—but their partners aren’t who you might expect.
A new study shows that some members of the octopus species Cyania Marat roam the ocean floor in hunting groups with fish that sometimes include multiple fish species at once.
Research published in the journal Nature on Monday found that famously intelligent animals organized the decisions of hunting groups, including what to hunt.
What’s more, the researchers observed cephalopod species — often called big blue or day octopus — stinging companion fish, apparently to keep them on task and contribute to the cooperative effort.
Octopuses are thought to avoid other members of their species and use camouflage to navigate alone. But the study suggests that some octopuses have surprisingly rich social lives – opening a new window into the wonders of life under the sea. It’s a sign that at least one octopus species has traits and intelligence markers that scientists once thought were common only in vertebrates.
“I think sociality, or at least attention to social information, is more deeply rooted in the evolutionary tree than we think,” said Eduardo Sambio, postdoctoral researcher at the Max Planck Institute of Animal Behavior and lead author of the research.
“We are very similar to these animals,” he said. “In terms of consciousness, they are at a very close level, or closer than we think to ourselves.”
To understand the inner details of octopus life, the researchers spent about a month diving on a reef off the coast of Eilat, Israel, and tracked 13 octopuses for a total of 120 hours using multiple cameras. The team followed the octopus for 13 hunts, during which they observed groups of two to 10 fish working with each octopus.
These predatory groups typically include several species of reef fish such as grouper and goatfish. Octopuses don’t seem to lead groups, but peck fish to enforce social order – often in blacktip groups.
“The high-strike are the main predators of the group. These are ambush predators, immobile, do not search for prey,” Sampaio said.
Octopuses poke fish to move the group.
“If the group is very quiet and everyone is around the octopus, it starts to sting, but if the group is moving in the habitat, it means they are looking for prey, so the octopus is happy. It doesn’t sting anyone,” Sampaio said.
Researchers hypothesize that fish benefit from such groups of predators, as an octopus can hide prey and reach into crevices to root for lunch. Octopus benefits because researchers believe they can go after fish for food, rather than doing speculative hunting.
“For the octopus, this is an advantage because it doesn’t need to sample or move around the environment,” Sambayo said. “You can see the fish.”
After shooting their video, the researchers fed all of their hunting footage into software that created a three-dimensional representation, then used another program to track each animal and record its position among others. It allowed the researcher to measure how close the organisms were to each other and which organisms anchored or pulled the group in one direction or another.
The data show that one particular fish species, the blue goatfish, will lead groups of wandering predators in that direction, but the school of fish will be delayed if the octopus does not immediately follow.
Sambayo explained that goatfish “explore the environment and find prey.” “Determinant of the Octopus Group.”
The researchers found no evidence that the species shared prey. All the species involved were generalists eating crustaceans, fish and molluscs, but whoever could catch the prey got the food.
However, questions remain, including whether some octopuses prefer to hunt with a favorite fish companion.
“Is the individual authorized?” Sambayo said. “Should I follow the blue sheep or follow Martha since I hunted with her before?”
It is also unclear whether this social hunting behavior is something octopuses learn or is innate.
“In my intuition, I think it’s something they learn because the smaller octopuses seem to have more difficulty cooperating with the fish than the larger ones,” Sambayo said.
Jonathan Birch, a professor of philosophy at the London School of Economics, studies animal sentience but is not involved in the new research. between living beings.
“It’s an important step beyond what you get in nature documentaries, where individual behavior is filmed,” Birch said.
He also appreciated that the study’s observations were made outside of a laboratory setting, where much animal cognitive research takes place. Octopuses are difficult to study outside of their natural environment. “They are more expressive in the wild and can do a lot more,” he said.
Some scientists subscribe to an evolutionary theory called the social brain hypothesis, which posits that primates and other animals have developed larger brains to process social information and cooperate with others.
“Octopuses were thought to be a problem because they are intelligent and yet solitary, so researchers were puzzled for a long time about what was going on there,” Birch said.
That left two possibilities: Either octopuses represent pathways to intelligence outside of social information, or scientists simply haven’t found a hidden octopus lifestyle that fits the theory of social intelligence.
“This study shifts the balance a little bit toward that second theory,” Birch said. “At least one type of octopus has a kind of rich social life.”
This article was originally published NBCNews.com
