Illustrative Image – Osman Temizel / Shutterstock.com
While octopuses are known to change color when dreaming, recent observations suggest these fascinating animals may also be prone to nightmares.
troubled dreams
This new research, previously published on the bioRxiv server, involved the close monitoring of a male individual of the Brazilian species Octopus insularis maintained at Rockefeller University in New York. Viewing hours of footage captured by cameras aimed at his pelvis, one could see sudden changes in his skin color accompanied by unusual movements as he appeared to fall asleep.
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The team theorized that the animal’s body language, much like the dog wagging its paws in its sleep, directly reflects the content Dream. On several occasions, the cephalopod would even wake up abruptly, violently shaking its limbs and emitting a jet of ink as if to ward off a predator.
“The behavioral sequences exhibited by this octopus upon awakening from disturbed sleep resembled behavioral responses to nightmares, night terrors, and other parasomnias in humans, with a narrative structure resembling state defensive behaviors. Vigilance in cephalopods,” the researchers write.
Since these observations only relate to a single specimen, it cannot currently be said that this is species-specific behavior octopuses In general. However, the possibility that these remarkably intelligent creatures’ dreams might reflect the darker aspects of their existence would not be surprising.
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An essential function
Interestingly, cephalopods and mammals are extremely distant in the family tree of life: our most recent common ancestor was a primitive flatworm that lived about 750 million years ago. However, this actual temporal gap did not prevent the two groups from developing the ability to dream, suggesting that this function is essential for intelligent life.
“The possible occurrence of this phenomenon in octopuses would shed unexpected light on the convergent evolution of sleep in distant organisms with complex neuronal structures,” the researchers conclude.