Do Octopuses Dream? Scientists Think They Just Might

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Blending in with your surroundings is a crucial (and fascinating) skill in the animal kingdom, which is why many animals can change colors on demand. Chameleons, seahorses, and octopuses can all do it — it’s one of nature’s coolest magic tricks! Interestingly, an octopus doesn’t just change colors to hide from predators; it also changes colors while sleeping. In one fascinating video, an octopus was captured changing colors while snoozing — and it’s amazing to see it dreaming in color!

In a video by @dan-gigandet, shared on Instagram by @octopus.fans, an octopus is filmed underwater. It is a pale yellow color at first, then turns a deeper yellow like a golden sunflower. Next, it becomes a brighter, almost white shade before transitioning into a darker, scaly pattern. The yellow, brown, and white patterns on its skin shift and change, even as the octopus remains motionless in the water. It’s mesmerizing to watch, and we just want to play this video on repeat.

Sleeping in Colors

Blue Ringed Octopus (Hapalochlaena sp.)

When awake, octopuses can change colors to blend in with their environment or to communicate.

Researchers know that octopuses change colors when they sleep, and they believe that octopuses could be dreaming while doing so. A 2021 study found that an octopus (Octopus insularis) will go through quiet and active sleep, just like humans. Changes in skin color and texture, eye and mantle movement, and arousal threshold all depend on which sleep state the octopus is in. The study found that the quiet sleep state had pale skin, closed pupils, and longer episode durations, whereas the active sleep state had dynamic skin patterns with varying colors and textures, rapid eye movements, and shorter episode durations. An octopus’s active sleep cycle seems similar to the rapid-eye movement (REM) seen in other mammals.

The study authors explained how they determined that the octopuses were sleeping when they changed color. They studied four octopuses over more than 50 days, video recording them for review. They found that the octopuses were sensitive to weak stimuli when awake, but needed a strong stimulus to evoke a response when in either sleep state. When awake, octopuses change colors and textures to camouflage with their surroundings or communicate, but when sleeping, the color changes are influenced by brain activity and are unrelated to their environment.

What About Dreaming?

Underwater photo of small octopus in tropical sandy turquoise sea bay

Octopuses go through two different sleep cycles: quiet and active.

It’s worth noting that the 2021 study referenced earlier does not confirm whether octopuses are dreaming during their active sleep or simply sleeping. Study authors Sidarta Ribeiro and Sylvia Medeiros told CNN, “It is not possible to affirm that octopuses dream because they cannot tell us that, but our results suggest that during ‘Active sleep’ the octopus experiences a state analogous to REM sleep, which is the state during which humans dream the most.”

The researchers added that if octopuses do dream, their dreams are most likely not like those of humans.

“If octopuses indeed dream, it is unlikely that they experience complex symbolic plots like we do,” Ribeiro and Medeiros said. “‘Active sleep’ in the octopus has a very short duration (typically from a few seconds to one minute). If during this state there is any dreaming going on, it should be more like small videoclips, or even gifs.”

More Evidence of Dreaming

Animals That Change Color- Octopus

Researchers have found more suggestive evidence that octopuses might dream, based on observed behaviors during sleep.

A 2023 study, per National Geographic, has provided suggestive evidence that octopuses might experience dream-like states during sleep. Scientists at the New York City Rockefeller University experienced something unusual one morning. They found their Brazilian reef octopus, Costello, wrapped around a PVC pipe in his murky tank. After reviewing footage, they saw that it appeared Costello was sleeping right before he woke up and seemed to “attack” the pipe and ink his tank. The researchers suggested that the octopus was possibly having a nightmare or remembering something stressful in his dreams.

After reviewing more camera footage, the researchers found other instances of Costello appearing to wake up from sleep and make odd movements. For example, on one occasion, the octopus turned deep red, spun around on the floor of his tank, thrashed his tentacles, and released ink — behaviors he might display in the wild to defend against predators.

“We are not trying to in any way, shape, or form give the impression that this is an open-and-shut case,” Marcelo Magnasco, a biophysicist and study author, told National Geographic. “But ignoring this as a possibility would be foolhardy.”

Smartie Pants

There are around 300 different species of octopuses, which come in nearly every color of the rainbow. Octopuses are known as being the most intelligent of all invertebrate animals, with the highest brain-to-body-mass ratios. Some studies have found that octopuses have both short- and long-term memory, as they can navigate back to their dens after traveling long distances. If any animal were going to have the ability to dream, we wouldn’t be surprised if it were an octopus!

The post Do Octopuses Dream? Scientists Think They Just Might appeared first on A-Z Animals.

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