Scientists Gather More Proof Octopuses May Actually Dream

Scientists Gather More Proof Octopuses May Actually Dream


Some time back, marine biologist David Scheel from Alaska Pacific University witnessed a female octopus named Heidi changing colors as she slept in her tank. The footage was available as part of a series called "Octopus: Making Contact," which aired on PBS. Scheel believed she was dreaming because the color changes matched with colors she had turned while hunting prey.

"If she is dreaming, this is a dramatic moment," Scheel said at the time.

Now, another octopus, this one named Costello, has exhibited similar but much more dramatic behavior, leading scientists to continue to ponder the question of whether or not octopuses really do dream.

According to a piece in National Geographic, observations of a sleeping octopus startling awake have scientists asking if it has nightmares or if it's just getting old.

Researchers at New York City's Rockefeller University arrived at work one morning to find the male Brazilian reef octopus kept in the lab doing something odd. His arms were wrapped inside a piece of PVC pipe as if he were trying to strangle it. The water in the tank was murky, which would signify inking.

Wondering what was going on, the team decided to review camera footage from hours earlier. What they saw on screen surprised them. Costello, who appeared to be emerging from sleep, demonstrated defensive behaviors before inking his tank.

The odd movements suggested Costello was recalling "something stressful" and possibly indicative of having nightmares, noted Marcelo Magnasco, a biophysicist at Rockefeller who co-authored a study on the strange phenomenon published on the biology website bioRvix.

The five authors, whose paper has not yet been peer-reviewed, caution that the observations and data are from a single octopus and that the reasons behind the unusual episodes are speculative at this point. But, together with the report on Heidi, you have to admit it seems feasible that cephalopods could dream. Why not? Other creatures besides humans do.

Another point is that throughout the rest of the day, the researchers never saw Costello repeating any of the same wild thrashing movements.

After that first strange episode, the team decided to examine more than 50 days of video footage focusing on Costello, looking for similar instances where he was stationary or asleep one minute then abruptly flailing about in a disorderly manner, or performing some kind of anti-predatory response, like inking his environment to escape the perceived threat.

As it happened, there were four recorded episodes when Costello was sleeping before waking up and showing erratic and violent behaviors. Two of them involved inking. In one instance, Costello turned deep red, spun around on the bottom of his tank several times, and then thrashed his tentacles before inking.

"The animal is clearly frantically trying to get away from something," Magnasco observed.

It's possible Costello was experiencing something like a nightmare during these unusual episodes, like reliving past traumas, the study authors suggest. He initially arrived with damage to two of his tentacles, possibly from encounters with predators before he was captured. That might be stuck in his memory, or the trauma of his removal from the sea and ending up in a tank could be the trigger.

Costello was legally caught and procured from a supplier in the Florida Keys in February 2021.

"We are not trying to in any way, shape, or form give the impression that this is an open-and-shut case," Magnasco acknowledged. "But ignoring this as a possibility would be foolhardy."

Rebecca West

Rebecca is a writer and editor for both print and digital with a love for travel, history, archaeology, trivia, and architecture. Much of her writing has focused on human and animal health and welfare. A life-long pet owner, she has taken part in fostering dogs for military members during deployment and given many rescued and surrendered dogs the forever home they always wanted. Her two favorite canine quotes are, "Be the kind of person your dog thinks you are," and "My dog rescued me."

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