09/04/2021 13:02
Clarín.com
International
Updated 09/04/2021 1:59 PM
In early 2021, an octopus named Marshmallow was the subject of an astonishing study.
Brazilian scientists studied him in a pond and saw that he suddenly changed color and his muscles moved while his closed eyes also oscillated.
Thus they discovered that the cephalopod was dreaming.
Now other researchers have determined that a close relative of the species,
the cuttlefish officinalis, is the most memorable animal.
To find out, experts from the
University of Cambridge
, the Laboratory of Marine Biology in Woods Hole, Massachusetts, and the University of Caen, proved that six old cuttlefish remembered where they were small bites of mollusks that were moved into a pond depending on the time of day. day, in the same way that young cuttlefish did.
The results were published in the journal
Proceedings of the Royal Society B
, and are the first evidence of an animal whose memory of specific events does not deteriorate with age.
The cuttlefish officinalis were studied in ponds in which they were putting food that was being moved from place as time passed.
They performed memory tests on 24 cuttlefish, an animal that lives for about two years.
Half of them were between 10 and 12 months old and the other half were between 22 and 24 months, which is
equivalent to about 90 years of humans.
“The cuttlefish were shown to be able to remember what they ate, where and when, and use this to guide their future feeding decisions.
The surprising thing is that they do not lose this ability with age, despite showing other signs of aging such as loss of muscle function and appetite, ”said
Alexandra Schnell,
from the University of Cambridge, who was the researcher who led the study. .
It is known that as humans age they slowly lose the ability to remember specific events.
This is called
episodic memory,
and its decline is thought to be due to deterioration of a part of the brain called the hippocampus.
But since cuttlefish don't have a hippocampus, things change.
The
vertical lobe
of the cuttlefish
brain
is associated with learning and memory.
This does not deteriorate until the last two to three days of the animal's life, which, according to the researchers, could explain why episodic memory is not affected by age in cuttlefish.
Cuttlefish have shown that they do not lose their memory as they age.
The study consisted of training the cuttlefish to approach a specific spot in their pond
marked with a black and white flag
. Then they were trained to learn that two foods they eat habitually were available at specific locations marked with flags and after certain specific delays. In one place the flag was waved and they were given a piece of
shrimp, their least favorite food
. The shrimp, which they like best, were offered to them in a different location where another flag was also flown, but only every three hours. This was repeated for four weeks.
The corollary was that the cuttlefish remembered what foods would be available, where and when they tasted it. To make sure they didn't just learn a pattern, the two feeding places were unique each day. All cuttlefish, regardless of age, saw which food appeared first on each flag and used that to determine which feeding spot was the best each time the flag was subsequently flown. This suggests that episodic memory
does not decline with age in cuttlefish
, unlike in humans.
Schnell explained: "The old cuttlefish were only as good as the younger ones at the memory task; in fact,
many of the older ones did better
in the testing phase. We think this ability could help cuttlefish in the wild. to remember who they mated with, so that they do not have the same partner again. "