In a lab in New York, a male octopus named Costello suddenly woke up from his sleep and started flailing his arms and releasing ink. Researchers believe this behavior is proof that octopuses have nightmares.
Researchers at a New York lab believe they have captured footage of an octopus having a nightmare. If true, it would suggest that octopuses, like humans, are capable of having complex and vivid narrative dreams.
The footage, captured with around-the-clock cameras at Rockefeller University in New York, shows a male Brazilian reef octopus named Costello dozing in his tank. Costello can be seen changing skin color while sleeping, a behavior that researchers believe may demonstrate a dream. Like a dog shaking in its sleep, an octopus may move and change color to reflect the nature of its dreams.
And Costello’s behavior offers possible evidence that the dreams weren’t all positive.
Reviewing the footage, the researchers observed several instances in which Costello suddenly awakes from his sleep, waving his arms around in apparent distress. In two recorded cases, it even releases ink, a common tactic for defending against predators.
“It was really weird, because he looked like he was in pain; it looked like it was in pain, for a while,” said Eric Ramos, a researcher at the University of Vermont who helped film the octopus. Live Science. “And then he woke up as if nothing had happened, and he resumed his day normally.”
This unusual behavior led researchers to speculate that Costello may have been having a nightmare.
“The behavioral sequences displayed by this octopus upon awakening from disturbed sleep were similar to behavioral responses to nightmares, night terrors, and other parasomnias in humans, with a narrative structure resembling awake defensive behaviors in humans. octopuses,” the researchers wrote of the behavior in their study, which has not yet been peer-reviewed.
“We hypothesize that the complex behavioral sequences displayed in these episodes suggest that octopuses experience parasomnias that may include nightmares that may disrupt their sleep,” the researchers concluded.
Octopuses are certainly capable of intelligent activity, as they are equipped with highly developed brains.
Although humans’ last common ancestor with them was a flatworm that lived about 750 million years ago, the researchers note that if the finding in this study is true, it appears that we both separately developed the ability to dream, indicating that dreaming may serve an essential purpose for intelligent life.
“The potential occurrence of this phenomenon in octopuses would shed unexpected light on the evolution of sleep in distant organisms with complex neural architectures,” the study concludes.
But while the idea that octopuses can experience complex dreams like humans do is exciting, it’s not the only explanation for why Costello may have exhibited this behavior.
In a statement to Live Science, Robyn Crook, a neurobiologist at San Francisco State University, said there is not enough evidence to prove that octopuses and other cephalopods dream. And even if they did, it’s hard to tell if they dream like humans.
Crook thinks something may have spooked Costello, causing him to display protective behaviors.
Another possibility that Costello has gone through senescence, a stage in an octopus’ life where its body begins to decay in preparation for death. For Crook, Costello’s movements in the video indicate more nervous breakdown and loss of motor control than a nightmare. And indeed, Costello died shortly after exhibiting these behaviors.
Even Ramos said Live Science that “I do not exclude that senescence may be one of the driving forces”. Some labs, he said, can euthanize octopuses before they begin to age, which could explain how Costello’s unusual behavior appeared to researchers.
However, Ramos noted that most labs also don’t monitor their octopuses around the clock, so they may have missed observing these behaviors.
For now, researchers agree on one thing: more research on octopuses and other cephalopods is needed.
“For all the studies that have been done,” Ramons said, “there’s still so much we don’t know.”
After reading the study on octopuses and nightmares, discover the coconut octopus, the cephalopod that uses tools and sometimes walks on two legs. Then read about the dumbo octopus, the tough octopus with dumbo-like ears that swallows its prey whole.