The male octopus was regularly seen forcefully jolting out of slumber and
doing strange behaviors, although it is unknown what caused this strange
behavior.
In a New York laboratory, researchers caught on camera an octopus acting in
a peculiar way that could be caused by nightmares. Over the course of a
month, scientists observed the octopus bolt out of a peaceful sleep and
thrash around in a manner that nearly looked to indicate the animal had a
sleep issue.
Or was this octopus actually dreaming? The animal may have responded in
this way for other reasons, and experts cautioned against jumping to
conclusions about the animal's behavior. Nevertheless, this conduct is
uncharacteristic.
"There's still so much we don't know," said
Eric Angel Ramos, a postdoctoral researcher at the University of Vermont who assisted in
filming the octopus. "For all the studies that have been done" on octopuses
and other cephalopods.
Four instances of an Octopus insularis named Costello appearing to sleep
peacefully in a tank before abruptly swinging its tentacles about in a
frenzy were recorded on video at a lab at The Rockefeller University in New
York. As a typical predator protection technique, Costello also fired a jet
of black ink into the water in two of these incidents.
Ramos told Live Science, "It was really bizarre because it looked like he
was in pain; it looked like he might have been suffering, for a moment." And
after that, he simply got up and carried on with his day as usual.
The study team reported these actions in a preprint (which has not been
peer-reviewed) submitted to the server
bioRxiv
this month. Some of these activities are akin to what an octopus may do when
facing a predator in the wild.
According to the scientists, "the animal may have been responding to a
negative episodic memory or exhibiting a form of parasomnia," or a sleep
condition, as a result. But they added a warning that nothing could be
inferred with certainty from these data.
Recently, additional information concerning octopus sleep has come to
light. According to a research released in 2021, animals exhibited a
two-stage sleep pattern that included "active" and "quiet" sleep, much to
how humans alternate between REM and non-REM sleep each night. Since REM
sleep is when humans dream the most, some researchers have speculated that
octopuses could also dream when in their "active" sleep period.
One specialist, who was not engaged in the observations, cautioned against
reading the octopus's behavior as dreaming.
According to
Robyn Crook, a comparative neurobiologist at San Francisco State University, we don't
know enough about the neurology of sleep in cephalopods to determine if they
even dream, much less have nightmares. And even if they do dream, she added,
it's possible that their dreams are entirely unlike from ours.
Crook remarked, "It's not something we could readily respond. The question
is quite philosophical.
Thus, she noted, despite the fact that the acts in this video are "very
interesting," it is most probable that they were not motivated by
dreams.
Crook said that the octopus may have just been frightened by anything. She
also suggested that the octopus could have been displaying
senescence-related symptoms. When an octopus enters this stage of its
existence, it is just before it dies and its body is beginning to
decompose.
Crook and her coworkers recently discovered a connection between senescence
and nervous system deterioration in a different octopus species, the giant
Pacific octopus (Enteroctopus dofleini). She didn't regard the arm motions
in the video as anti-predator behavior, but rather as a sign of senility,
which, in her opinion, is characterized by a loss of motor control.
According to Ramos, Costello's species only survives for 12 to 18 months,
and he passed away soon after these events. "I don't exclude that senescence
could be one of the drivers of this," he said to Live Science.
According to Ramos, it's conceivable that this behavior stood out since
many laboratory octopuses are put to death before they may begin to senesce.
Additionally, he said, most labs don't continuously record their octopuses,
so other labs may have missed opportunities to catch comparable
behaviour.
