Have you ever seen a whale breathe?
Stomata and evolution of whales
The jets of water that rise from the bottom of the sea look spectacular. However, the way whales we traditionally perceive as transflation is actually exclusive to humpback whales.
All cetaceans on Earth today can be divided into toothed whales and baleen whales. But whatever kind of whale it is, it evolved from some kind of mammal on land about 50 million years ago.
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The prevailing view now is that the common ancestor of modern whales is a mammal called the Pakistani whale. Looks like a dog with limbs like a normal mammal. However, there is a group of scholars who disagree with this view because it has a fatal problem, the nostrils.
In a 2009 national geographic show, a biologist asked this question. Nowadays, whether cetaceans or dolphins, their nostrils grow on the top of their heads. The mainstream of academics believes that the cetacean ancestor Bucky whale has its nostrils growing above its mouth.
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However, according to the restoration of the original whale and the Dragon King whale, we can see that the evolution of the whale is just like the evolutionary theory describes. Primitive whales slowly moved from land into the ocean to live, and in addition to evolving limbs into flippers, their nostrils were constantly moving upwards. It's all about making ventilation easier.
Scientists speculate that whales were basically adapted to marine life about 30 million years ago, but it wasn't until 10 million years ago that whales' nostrils officially evolved into what we see them today. In other words, the position of the nostrils and mouth alone took the whale 20 million years.
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But moving the nostrils from the front of their mouths to the top of their heads is not as simple as we think. I don't know if everyone has choked when drinking water? This is because the esophagus and trachea of all terrestrial mammals today are connected. This allows us to breathe with our mouths when our noses are not ventilated.
Won't whales choke when they eat?
In fact, we said this earlier. Whales have evolved to move their noses from above their mouths to the top of their heads so that their trachea and esophagus are separated.
In this way, when the whale eats, it does not need to consider whether it will choke on the nose after drinking a large mouthful of water, and can eat with its mouth wide open. Crocodiles of this construction do not have.
We have the impression that crocodiles spend basically all day in the water waiting for their prey, showing only their eyes and nostrils. As soon as there is prey approaching, the crocodile will drag the prey into the water and drown.
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In fact, crocodiles also have certain risks in doing so. Crocodiles, like us humans, have an esophagus connected to the trachea. Opening your mouth in the water also carries the risk of choking on water. As a result, valves have evolved in crocodiles' mouths, allowing them to isolate air when they open their mouths.
The breath of a whale
The nose of a whale is also called a stomata. When relaxed, the stomata are covered by a myocutaneous valve, which, like the valve in the crocodile's mouth, acts as a barrier to water. When they surface, the pores open, spewing out high columns of water.
However, these water columns are not the water in the whale's body, but the water vapor formed by the residual water outside the nostrils being rushed into the air by the air current of high-speed breathing.
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Leaving this aside, whales breathe the same way humans do, taking a deep breath and holding it in the water. This means that whales, like humans, do not die of forgetting to breathe. However, in the case of panic, danger, and fear, they will suffocate because they cannot breathe in time.
Notice the scene in front of you, a group of sperm whales standing vertically in the sea, like a group of eerie coffin arrays, looking very frightening. But don't be afraid, this is actually what sperm whales look like when they sleep.
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Sperm whales can dive to a depth of more than 2,000 meters and stay for two hours as long as they take a big breath. When sperm whales are sleeping, they float in swarms near the surface of the water, and even fishing boats pass by them without responding.
According to observations, sperm whales spend only 7% of their time sleeping each day, and about 10 to 15 minutes at a time, which is almost equivalent to how long they hold their breath. Compared to the state in which we sleep one night and are still thunderous, sperm whales are indeed not easy to suffocate when they sleep.
In addition to sperm whales, some whales will float on the surface of the water to sleep, sleep with their nostrils exposed, and breathe as they sleep.
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Some toothed whales use a form of sleep called USWS, which is manifested in a slow swim on the surface of the water. In this way of breathing, the whale will sleep while leaving a part of the consciousness to breathe, and there will also be a part of the consciousness to hold the breath.
Animal sleep
In fact, most animals in nature have strict sleep schedules. For example, giraffes can only enjoy 30 minutes of deep sleep a day with fragmented time.
Dolphins hold their breath for only 10 minutes at a time, but there is a bottlenose dolphin that sleeps for one-third of the day every day.
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In order to ensure that they will not be choked to death when they sleep, dolphins will generally take turns resting on the left and right brains, first letting one side of the brain into deep sleep, and the other side of the brain to stay awake. This mode of sleep is known as "single hemisphere slow-wave sleep."
In addition, this peculiar way of sleeping birds also uses. When you see a bird turning a blind eye to you, it may be sleeping. Legend has it that Swift never lands, but always flies in the sky, which is also because Swift has mastered this magical skill and can fly while sleeping on a long flight.
In short, most wild animals can't sleep as peacefully as we do, they are a bunch of sleepy bugs that want to sleep but can't sleep.