Octopuses may have both good and bad dreams, just like humans do, a new study has claimed.
In the survey, which has yet to be peer-reviewed, scientists from New York City's Rockefeller University documented behavior by a captive male Brazilian reef octopus that that they say looks very similar to a nightmare.
Some parts of the footage, though, showed Costello waking up with a start and then flinging his arms around and squirting out ink, the same as he would do in the wild when trying to escape a predator, according to the scientists.
"The behavioral sequences displayed by this octopus upon emerging from disturbed sleep were similar to behavioral responses to nightmares, night terrors, and other parasomnias in humans, with a narrative structure resembling waking defense behaviors in octopuses," the study pointed out.
The researches added that they “speculate that the complex behavioral sequences displayed in these episodes suggest octopuses experience parasomnias which may include nightmares with the potential to disrupt their sleep.”
It remains unclear whether such behavior affects all octopuses, given that the study only looked into the one cephalopod. The Rockefeller team, for their part, expressed hope that reporting the incident would prod other scientists to keep an eagle's eye on the octopuses’ behavior to confirm the findings.