Octopuses can change color while sleeping, most likely this is the impact of dreams on the animal’s body.
At the Federal University of Rio Grande do Norte, neuroscientist Sidarta Ribeiro and colleagues discovered that octopus sleep is also divided into active and passive phases . After several days of monitoring four octopuses of a common species in the wild (scientific name is Octopus vulgaris), the research team collected more than 180 hours of video material and came to remarkable conclusions. idea.
According to Mr. Ribeiro, octopuses spend about half of their day sleeping. “ In silent sleep, they lie motionless for a long period of time – very quiet, and their eyes are closed – they also breathe very regularly and softly .”
What is this octopus dreaming about?
Every 30-40 minutes, this passive sleep is interrupted by a short period of active sleep lasting 1-2 minutes. During this time, the octopus’s body changes color and surface layout. The octopus’s eyes and tentacles move, and the suction cups contract continuously. “Clearly this is a very active sleep phase ,” Mr. Ribeiro said.
The research team tested whether the octopus really slept by playing videos related to crabs – the octopus’s favorite meal. “ When we stimulated the animal visually or with vibrations, it did not react at all ,” neuroscientist Ribeiro said, adding that this action was in stark contrast to the behavior of awake octopuses. “ If they were really dreaming, they would have been dreaming for up to a minute .”
This active sleep period of the octopus, although short, is clearly distinguished from passive sleep; While dreaming, octopuses’ skin darkens and they move slightly. “ In about 40 seconds, they suddenly change color and body surface structure. The eyes of octopuses move ,” Sylvia Medeiros, a graduate student participating in the research, responded to the press. The octopus’s strange actions take place about every 30-40 minutes.
Also according to Medeiros, the octopus’s dreams (if they exist) cannot be too complicated or have any meaning, because the active sleep phase is very short. Octopuses have the ability to solve problems like many other species including primates. It is also possible that dreams help octopuses improve their brain abilities and cope with difficult problems better.
Carrie Albertin, an octopus researcher at the Marine Biological Laboratory located in Massachusetts, said: Octopuses often lie still in their nests, they often sleep and may even dream.
Electroencephalogram shows that sleeping octopuses have brain waves similar to humans. (Photo: Depositphotos).
“I think when you look at these animals, it’s hard to deny that something is going on, but it’s important to identify them, to conduct research so that scientists can clearly delineate concepts ,” Ms. Albertin commented. “ That’s exactly what [the Brazilian research team] did .”
She believes that the newly published research is the first solid step in clearly identifying each octopus’s sleep stages.
Previously, scientific evidence showed that the ancestors of octopuses and humans were separated by more than 600 million years of evolution. Most scientists believe that their behaviors are very different from humans.
“All animals have the same sleep cycle, even animals with simple structures like jellyfish or fruit flies. Only vertebrates have two sleep stages, NREM and REM ,” said scientist Sam Reiter.
Therefore, the results of research on octopus sleep open up a new source of knowledge, proving that human sleep cycles are quite similar to octopuses.
“Even though different and far apart species of organisms can evolve a 2-phase sleep cycle independently, such as octopuses – animals with a brain structure completely different from vertebrates,” Leenoy said. Meshulam – a physicist at the University of Washington – told New Atlas.
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