How the dolphin sleeps: the amazing abilities of mammals

Dolphins belong to the order of cetaceans, suborder of toothy whales. In order to rest, it seems to us, it is enough just to close our eyes and fall asleep. And people do not even suspect that this can happen somehow differently. But how does the dolphin sleep ? This question has always been interesting, because the toothed whales sleep quite differently from other representatives of the order of mammals.

These animals sleep in the truest sense of the word on the wave. That is, they swim and at the same time rest. Dolphins are constantly in motion, so they get very tired, and like any living being, they also need to sleep.

Dream or life?

For a long time scientists were sure that cetaceans do not sleep at all. After all, there were certain grounds for these assumptions. Therefore, how the dolphin sleeps, was a mystery to all.

First, if he falls asleep, he can be eaten. Secondly, strange as it sounds, but he can drown. Yes, it is to drown, because you need to breathe in order to sleep. But there is no air at the bottom of the sea.

Scientists also assumed that dolphins sleep in snatches. Another reason why it was supposed that dolphins do not sleep is cold. If the mammal falls asleep, it will easily freeze. This is due to the fact that when the body moves the dolphin warms up, and when the sleep comes, it quickly cools. Given all the above features, for a long time scientists could not determine how the dolphin was asleep, and whether he could do it at all. But soon the mystery was solved.

So, there is a lot of evidence that sleep for these mammals is life-threatening. But how to be? Without sleep, life is impossible not only for the dolphin, but for any animal on earth, in the air and in the water. Everyone sleeps, but only each in his own way.

All the time on the alert

A dream for dolphins is something interesting and unusual. After all, they must be vigilant, because predators do not sleep and can easily kill. Some observations have shown that dolphins cover one eye. But why are they doing this? Then the following question arises: "Do dolphins sleep with one open eye?". We will try to answer it.

Dolphins sleep on the waves, as it allows them not to drown. So, they often make inhalations that are necessary for life. If the dolphins slept deeper, it would be harder for them to breathe, as it was time to come to the surface and inhale. For these reasons, the mammal is asleep at the top. But that is not all. An interesting fact is how the dolphin sleeps, his eyes are not completely closed.

It turns out that the two hemispheres of his brain sleep in turn. First one rest, and the second one is awake, and vice versa. The main thing is that the hemisphere sleeps in the same length of time, and while one part of the brain is asleep, the second is watching the surrounding world. This allows the animal to be careful to be safe.

"Lunatics of the Sea"

Often dolphins are called "sleepwalkers" because they are in a dream are in constant motion. This is necessary not only to breathe in, but also not to freeze. The body of the dolphin generates heat during swimming, which allows the mammal to warm up. In this case, "sleepwalking" is very necessary, because it is protection from both cold and predators.

Not all cetacean mammals sleep in motion. This ability is possessed by those who have a body weight of tons. For example, a killer whale, whose weight is about six tons, sleeps on the surface of the water completely motionless. Since there is a sufficient amount of subcutaneous fat in her body, which keeps the heat longer and keeps her on the water.

If the weight of the mammal is less than 100 kilograms, then it will not be possible to sleep motionless. It is necessary to move during sleep. The young killer whales also sleep in motion, as they did not gain the weight that is necessary. When they accumulate a sufficient amount of subcutaneous fat, they will also safely doze off in a stationary state.

Fantastic abilities of dolphins

As you know, toothed whales sleep in motion, and this is not the only interesting feature of these amazing mammals. The second is that they rest with their eyes open, and to be more precise, the dolphins sleep with one open eye. Why is this happening? Everything is simple enough: dolphins possess a unique ability: when one hemisphere of the brain is asleep, the opposite eye is open, in this way they observe others. For example, for their babies. This is very convenient, because they are guarding "their own".

These animals do not have a paradoxical phase of sleep, which allows people to see dreams. Since dolphins sleep with their eyes open, they can not be in the land of dreams.

Sleep on land and in water: what's the difference?

If these mammals were sleeping with their eyes closed, then this would be a continuous threat to life. After all, on land, everything is much simpler: there is where to hide from a predator, and there is no problem with air. In the sea, it is impossible to do this, so we have to adapt to this habitat. If on land a dream is really a luxury, as a solid surface is felt under the body, then in the water one must be able not only to rest, but also to be on the alert all the time.

Thanks to the zeal and observance of scientists, the mystery about how the dolphin is sleeping is successfully solved.