You can not believe that there is extraterrestrial life in the universe, but you have to admit that some creatures on Earth are indeed different from other creatures and look like another form of life.
If you want to find such a creature, it is actually not difficult, there is a very common animal, so many people think that it is an alien creature, that is, cephalopods. Speaking of cephalopods, you may not be very clear, specifically, should be called cephalopods, which are divided into nautilus subclass and subclasses. Among them, there are several animals in the suborder Puma that we are very familiar with, namely octopus and cuttlefish.
Octopus and cuttlefish are very strange creatures, which are very different from other creatures on Earth. Not to mention that their appearance is very unique, there are many tentacles, looking at the inside of their bodies, it is even more strange.
Unlike us, cuttlefish have three hearts, 2 of which are in the gills and 1 for the other parts of the body. Moreover, the blood supplied by the heart of the cuttlefish is not red like ours, but blue, because they do not have hemoglobin in their blood, but instead copper protein.
Not only that, but a recent study showed that the brains of cuttlefish are also very different from other organisms. We always say that when people get old, their memory will decline, and many things will not be remembered. Not to mention old age, even young people, if you want to remember specific information about something a few days ago, it may be a little difficult.
However, for cuttlefish, remembering these things and information seems like a breeze. Even old cuttlefish have the same memory as when they were young, and even when they were young, they can remember clearly what they ate at which meal. Scientists at the University of Cambridge in the United Kingdom have discovered this amazing ability of cuttlefish through a series of experiments.
The researchers selected a total of 24 cuttlefish and divided them into two groups. Fortunately, this creature does not have a long lifespan, so it is not very difficult to conduct such a study. One group is between 10-12 months old and belongs to the juvenile cuttlefish, and the other group is 22-24 months old cuttlefish, which already belongs to the stage of entering old age.
They trained the cuttlefish to learn when and where they could meet what animals they could encounter. There are two kinds of animals that appear, one is the grass shrimp that cuttlefish prefer to eat, and the other is the large shrimp. In other words, these cuttlefish remember the three most critical elements: time, place, and event. Together, these three elements constitute a kind of memory - accidental memory.
Through such training, cuttlefish can learn how to get their food at the right time and place. The results showed that both juvenile young cuttlefish and decaying old cuttlefish spent the same amount of time learning how to find the best food, and ultimately took the same amount of time choosing food.
Alexandra Schnell, a comparative psychologist at the University of Cambridge, points out: "These cuttlefish can clearly recall when and where they have eaten what kind of food they have eaten, and use it as an important reference for their future predation decisions." The most surprising thing is that as they age, even if they show the degradation of aging and aging, such as muscles and appetite, these memories do not dissipate at all. ”
In other animals, scientists have also found situations similar to occasional memories, such as mice and some birds. However, our understanding of occasional memories in animals is very limited, after all, they cannot directly feedback to us what such memories are. Through experiments alone, it is really difficult to understand what kind of mechanism and role such memory plays.
And the researchers found that the same occasional memory, cuttlefish and mice and birds are different, because this memory of cuttlefish does not decline with age. Schnell describes: "Older cuttlefish performed as well as young cuttlefish in terms of memory tasks, and even some were stronger than young cuttlefish during the test. ”
One important peculiarity of cuttlefish's brain is that there is no hippocampus, which is very different from our vertebrates. The hippocampus is an important part responsible for memory, and it is responsible for functions such as storage conversion and orientation of long-term memory. Maybe our hippocampus is limited and will begin to degenerate as we get older?
Of course, the memory of cuttlefish is not forever degraded. However, it is only two or three days before death that the occasional memory and learning ability of these cuttlefish decays – but this is no longer important.
So, what are the benefits of these cuttlefish evolving such memory capabilities? Is it just for eating?
No. The researchers believe that this may still be traced back to mating and reproduction.
Cuttlefish do show very different characteristics from other animals in old age, in addition to maintaining super memory, they will also mate, and cuttlefish only begin to mate after entering old age. The researchers believe that these two events are not coincidences, but are necessarily related.
They believe that for older cuttlefish, it is very important to remember who they have mated with. Do not repeatedly mate with the same opposite sex, otherwise it will limit the spread of genes. When an elderly cuttlefish realizes that the opposite is their former partner, they will turn away, looking for another opposite sex that has not mated, helping to spread their genes more widely.
However, this is only a guess of the researchers. Exactly why cuttlefish have such memory ability needs more research. It's just that for people at present, a "special function" of cuttlefish has been discovered, which makes their identity more mysterious.