Can dolphins breathe underwater?

dolphin

Dolphins belong to Mammalia, Cetaceans, Toothed Cetaceans and Dolphins, with nearly 62 species, which are distributed in all oceans of the world. It is 1.2 ~ 4.2 meters long and weighs 23 ~ 225 kilograms. Dolphins generally have sharp mouths, and there are about 100 sharp teeth in the upper and lower jaws. They mainly feed on small fish, squid, shrimp and crab. Dolphins like to live a "collective" life, and the number ranges from a few to hundreds. Dolphin is a marine mammal with superb skills and intelligence. After training, I can play table tennis, jump in the ring of fire and so on. Dolphin's brain is the most developed among animals except humans. Human brain accounts for 2. 1% of his body weight, and dolphin brain accounts for 1.7% of his body weight. The dolphin's brain consists of two completely separate parts. When one part is at work, the other part gets enough rest, so it can stay awake for life. Dolphins judge the distance, direction, position, shape and even the nature of objects by echolocation. Some people do experiments, blindfold dolphins and wade in muddy water. They can catch up with the food thrown at them quickly and accurately. Dolphins not only have amazing hearing, but also superb swimming and unusual diving skills. Some tests show that the diving record of dolphins is 300 meters deep, while people can only dive 20 meters without diving suits. As for its swimming speed, it is unmatched by human beings. The speed of dolphins can reach 40 kilometers per hour, which is equivalent to the medium speed of torpedo speedboats.

In the kingdom of cetaceans, there are the most species of Dolphinidae, and there are more than 30 known species in the world. Although some species are called whales, such as killer whales and fake killer whales, they are actually members of the dolphin family.

Dolphin is a clever animal. They don't run away from people like timid animals in the forest, and they don't show their teeth when they meet people like wild animals in the mountains. Dolphins always show a very docile and amiable appearance and approach people. Compared with dogs and Malays, they are sometimes even more friendly to humans.

We have heard many stories about dolphins saving people from drowning, and reports about dolphins playing with people are often heard, and some stories even become sensational news. After learning and training, dolphins can even imitate the voices of some people. In 1970s, three American scientists taught two dolphins 25 words. Recently, four scientists, including Dr. Owens of the Pacific Foundation, trained two dolphins and spent three years teaching them 700 English words. However, some scientists believe that the "language" or "dialect" of animals should not be described too strangely.

But dolphins do have unusual intelligence. Its brain size and quality are also among the best in the animal kingdom. At present, scientists have two different views on the intelligence of animals: one thinks that chimpanzees are the most evolved and capable of all animals; The other thinks that the intelligence and learning ability of dolphins are similar to those of apes, or even higher. Therefore, some people call dolphins "wisdom in the sea".

In order to prove that dolphins can learn, as early as 1959, a man named Lili did an experiment on a dolphin. He inserted electrodes into the pleasure center and pain center of dolphins. When current stimulates the pleasure center or pain center of dolphins through electrodes, it will produce pleasure or pain. Then the dolphins are trained to touch the metal pieces on their heads and control the on-off of the current. If the electrode is inserted into the pain center of the dolphin, as long as it is trained for 20 times, the dolphin will choose to cut off the power supply to make the pain disappear. If you are a monkey, you need hundreds of trainings to learn to control the switch. This shows that dolphins have stronger learning ability in some aspects.

Dolphins are friends of human beings, and they are very willing to get close to human beings. Dolphins at Mon Kemi Beach in Australia have established friendship with human beings, which has brought great joy and surprise to people. Maybe there will be more dolphins in the future, and they will establish contact with humans in more places. This wish is not an illusion: with the deepening of people's research on dolphins, we will uncover more secrets about dolphins, and then our communication with dolphins will be easier, more intimate and more friendly!

Speaking of dolphins, people have heard that they have extraordinary wisdom and ability. In the aquarium, dolphins can perform various wonderful jumping movements according to the instructions of the trainer. They seem to understand the information transmitted by human beings and take action. People can't help but wonder how smart this beautiful marine animal is. So, how high is the wisdom and ability of dolphins? Is it possible for them to increase communication with humans? Starting with the structure and ecological characteristics of dolphin brain, this paper discusses its wisdom.

The IQ of dolphins is difficult to determine.

Dolphins can do all kinds of difficult acrobatics, and they are obviously quite smart animals in the sea. But what is the actual intelligence of dolphins? Psychologically speaking, the word "intelligence" contains three meanings: one is the ability to adapt to various situations; The second is the ability to learn from past experience; The third is to use symbolic things such as language or symbols to engage in "the ability of abstract thinking."

According to observing the behavior of wild dolphins. As well as the communication between dolphins and humans when performing acrobatics, it is speculated that dolphins have strong adaptability and learning ability; But at present, it is impossible to prove that dolphins use language or symbols for abstract thinking. However, even without scientific conclusive evidence, it cannot be considered that dolphins have no abstract thinking ability.

If dolphins really have the ability of abstract thinking, how does it use this ability? To what extent? These are all interesting questions. But now, it is not easy to find the answers to these questions, because even the wisdom possessed by human beings is still unknown.

Although dolphins belong to mammals like human beings, due to different living environments, there are not many opportunities for contact with each other, so human beings have very limited understanding of the potential ability of dolphins. So, what methods do humans use to study and explore the intelligence of dolphins? At present, the following two methods are mostly used: one is to calculate the potential ability of dolphins according to their anatomical characteristics; The second is to actually observe the behavior of wild dolphins and infer their wisdom from the aspects of behavioral purpose and function.

The brain is as developed as primates.

Anatomically, the dolphin's brain is very developed, not only large but also heavy. The sulcus on the brain hemisphere of dolphins crisscross, forming complex folds. The number of cells and nerve cells per unit volume of cerebral cortex is very large, and the distribution of nerves is quite complicated. For example, the Atlantic bottlenose dolphin weighs 250kg, and its brain weighs about 1.500g (similar to that of an adult male). The ratio of brain weight to body weight is about 0.6, which is much lower than that of humans (1.93), but higher than that of primates such as gorillas or monkeys.

As for the wrinkles formed by the sulcus in the cerebral hemisphere of dolphins, according to the research, the wrinkles of Atlantic bottlenose dolphins are even more complicated than those of humans. The surface area of their cerebral cortex is 2500 square centimeters, which is 1.5 times that of humans. The density of nerve cells in dolphin brain is almost the same as that of human or chimpanzee. In other words, dolphins have more nerve cells in their brains than humans or chimpanzees. Therefore, whether from the ratio of brain weight to body weight or the number of wrinkles in cerebral cortex, the memory ability or information processing ability of Atlantic bottlenose dolphins is comparable to that of primates.

Try to understand the language of dolphins.

Because the memory ability and information processing ability of dolphin brain are equivalent to those of primates, if humans can communicate with dolphins, they should be able to get a lot of valuable information about marine animals and learn different expressions and thinking modes. When diving with dolphins, you will find that dolphins are quite noisy animals. According to the recorded investigation records, dolphins use ultrasonic calls with frequencies above 200-350 kHz for "echolocation", while human hearing range is between 16-20 kHz, so human beings cannot hear the ultrasonic waves emitted by dolphin echolocation. Therefore, the dolphin calls we hear in the water may be part of the low-frequency sounds that dolphins use to communicate with each other.

The premise of human communication with dolphins is to understand the language of dolphins, so it is necessary to analyze the correlation between the sound and behavior of dolphins. In fact, as long as there is suitable recording equipment, the sound of dolphins can be analyzed. However, the parallel connection between sound and behavior is not easy to master. At present, people can't exactly understand the meaning of various sounds made by dolphins.

In order to let humans communicate with dolphins, the second method is to let dolphins learn human language. More than 20 years ago, experts from Ocean University of America used this method to develop the intelligence of dolphins. At present, under the training of experts, dolphins have been able to learn and understand the meanings of words and complex sentences from the gestures of trainers, and make appropriate responses, but they have not yet reached the realm of free exchange of information with people.

Whether studying the correlation between dolphin's voice and behavior or teaching dolphins to learn human language, the ultimate goal of mutual understanding and communication between humans and dolphins is still quite far away.

The way dolphins sleep.

Dolphins seem to swim around forever without sleep. Dolphins are mammals. They used to live on land, but later they went back to live in water and breathed with their lungs. If they continue to sleep in water, dolphins will die because they can't breathe. Do they really have to sleep? If they can sleep, do they sleep on land or in the sea?

In fact, if we can observe dolphins carefully for a period of time, we will find that they sometimes close one eye when swimming. After investigating their brain waves, it is known that one side of their brain will be asleep. That is to say, although swimming continues, the left and right brains are taking turns to rest.

If we can work while sleeping like dolphins, and rest our left and right brains alternately, we can use it wholeheartedly, and we are not afraid to miss the station when sleeping in the car.

Dolphins are desperate to protect their young.

If the female dolphin miscarries unfortunately, in order to give the calf with no activity a chance to breathe, she will desperately push the calf to the surface with a kiss, repeat these actions, and even stop foraging for two days.

According to people in the aquarium, once the dolphin dies, the mother dolphin will try her best to revive it, but if it lasts too long, even the mother dolphin will die of fatigue. Therefore, the calf's body must be salvaged as soon as possible. Perhaps this can prevent the mother dolphin from being too sad and restore her strength. However, it is not easy for the staff to remove the dead dolphins. Mother dolphins will protect dolphins from ships and compete with staff for endurance.

Does the mother dolphin know that the baby dolphin is dead? Or do you desperately want to push the dolphins to the surface because you feel sorry for them? Or is it just animal instinct? Perhaps dolphins do have some rationality that humans can't understand, and the details are still unclear.

Dolphins rescue their victims.

In ancient Greece, there was a story about dolphins rescuing drowning people: On one occasion, Aleon, a famous Greek lyric poet and musician, participated in a music competition organized by a wealthy Italian businessman and won a huge prize. He returned to Corinth, Greece by boat with this wealth, but on the way, the crew were jealous of him and wanted to kill him. Before he died, he asked to play another song. The wonderful music attracted a large group of dolphins. Aleon jumped into the sea, and the dolphin carried him on his back and swam to a safe place, so Aleon escaped. This story shows that the relationship between humans and dolphins was quite good in ancient times. So what is the situation between dolphins and dolphins?

1in June, 1994, when the researchers conducted an ecological survey of dolphins in the Pacific Ocean, they observed that a dolphin was hit by a harpoon and was in a coma. Not far away, another dolphin swam over and pushed the injured species to the surface. Its sound seemed to awaken the injured dolphin in a coma.

Dolphins can identify friends and enemies.

When investigating wild dolphins, researchers found that dolphins were usually reluctant to approach people at first, and seemed to be aware of the existence of strange objects. However, when they realize that humans have no intention, the vigilance of dolphins gradually declines, and they can even reach a distance. They will shake their heads and observe people. As long as one of them approaches people inadvertently, the other dolphins will swim slowly.

Near Chaco Bay in southern Italy, more than ten Atlantic bottlenose dolphins swim to the beach every day. These dolphins don't seem to mind human harassment. They are used to the food and bait given to them by human hands. Therefore, even wild dolphins will live in harmony with human beings if given the right opportunities.

But human beings have to get rid of the prejudice of "the spirit of everything" and stay in the world of dolphins. Find other ways to communicate with dolphins.

Jack the genius navigator

In Wellington, the capital of New Zealand, there is a unique dolphin monument which reads "Jack the Genius Navigator".

187 1 year, the sailboat "burini" passed through Cork Strait, New Zealand, and was trapped in the "Death Canyon" for a whole day due to sudden weather changes. It was about to be destroyed, and the desperate captain crossed his chest feebly. Suddenly, his eyes lit up, and a big silver-gray dolphin jumped out of the stormy waves, looking back and forward from time to time, as if to say, "Please rest assured, my friend, I know how to go out and get rid of death." The captain seemed to see the lighthouse during the night flight and ordered to follow the dolphins without thinking. The great dolphins finally led burini people out of the land of terror.

Since then, miracles have appeared. This silver-gray dolphin has been wandering around the strait, leading the passing ships year after year. Whenever a boat comes, it will always jump out of the water and wave its tail fin to welcome it. But it bypassed the reef and escaped the turbulence, which enabled the ship to escape. The crew affectionately called it "Jack".

19 12 years, Jack ended his 40-year career as a volunteer pilot and passed away quietly. The local people attached to it, and divers found its body, covered it with a national flag, held a funeral for it, and later carved a bronze statue for it.

Dolphins pay attention to division of labor in hunting.

Dolphins move in groups in the process of hunting. Not only that, na-ture website reported that a recent study on the coast of Florida showed that each dolphin has its own clear division of labor in hunting.

Cooperative hunting is found in many animal groups, such as chimpanzees.

But each individual has his own specific job in the group, just like in a football team, each player has his own division of labor, which is rare in animal groups.

American researchers observed two groups of dolphins, one consisting of three and the other consisting of two to six. The researchers identified each dolphin by marking their fins and observed their 60 hunting activities.

It is found that in the process of collective hunting, one of the two groups of dolphins always plays the role of "driver", while the other group of dolphins plays the role of "obstacle". The "driver" dolphins will drive the small fish around them into the encirclement formed by the obstacle dolphins.

This kind of individual division of labor in hunting has only been found in African lionesses in the past. A lioness waits in the center of the whole hunting scene, while other lionesses attack prey from all directions.

Regarding the special division of labor among dolphins discovered this time, the researchers said that it is still uncertain whether this special hunting method exists in all dolphins or only in a certain area.

Why do dolphins swim fast?

A good figure is a prerequisite for swimming fast. But even the best figure, in nature, if you want to be a swimmer, there are still many details to be perfected. When animals swim in the water, they usually cause some small eddies. These small eddies affect the swimming speed of animals. Dolphins and sharks have different ways to solve this problem. On the dolphin's body, the slippery skin is not tight, but elastic. Dolphins shrink their skin when swimming, thus forming many small pits on their skin, in which water is stored. In this way, a "water cover" is formed around their bodies. When the dolphin swims fast, the "water cover" covers its body and moves with it. With the help of this water protective layer, dolphins swim with little friction and will not cause whirlpool.

Dolphins have a long history of saving lives.

1949, the wife of a lawyer in Florida, USA, disclosed her strange experience of being rescued from drowning at sea in Natural History magazine: when she was swimming at a beach, she suddenly fell into an underwater undercurrent, and rows of turbulent waves came at her. Just when she was about to go into a coma, a dolphin swam quickly, gave her a sharp push with its sharp beak, and then pushed her several times until she was pushed into shallow water. After waking up, the woman looked around to see who saved herself. However, there is no one on the beach, only a dolphin is playing in the water not far from the shore. In recent years, there are more and more similar reports, which shows that dolphins were never invented by people.

Dolphins will not only push drowning people to the shore, but also come forward to rescue sharks when they eat people. 1959 in the summer, the passenger ship "Rio Arteiro" crashed in the Caribbean, and many passengers struggled in the rough sea. Unexpectedly, it never rains but it pours. A large group of sharks came around and everyone would be buried in the belly of the fish. At this critical juncture, groups of dolphins suddenly appeared like "heavenly soldiers and heavenly generals", pouncing on greedy sharks, driving away demons in the sea and turning passengers in distress into safety.

Helping the weak is instinct.

Dolphins are always an animal that helps people in trouble. When people are in danger in water, they often get its help. Dolphins have also won the reputation of "lifeguards at sea", and many countries have promulgated laws and regulations to protect dolphins. So why do dolphins save people? Before people fully understood dolphins, they were always thought to be sent by God to protect human beings. Due to the progress of science, the understanding of dolphins is further deepened, and its mystery is gradually uncovered.

Zoologists have found that dolphins are not limited to humans. They will rescue their sick companions.

During the period of 1959, American zoologist De Herb Nale and others saw two dolphins swimming towards a dolphin injured by explosives, trying to rescue their companions. Dolphins also help newborn dolphins, and sometimes they seem blind. In an ocean park, a little dolphin died at birth, but it was pushed out of the water by its mother. In fact, almost all objects that do not actively move in the water will attract the attention and great enthusiasm of dolphins and become their "rescue" objects. Some people have done many experiments, and the results show that dolphins will do the same thing to anything floating in front of them, whether it is a dead turtle, an old air cushion, a lifebuoy or a wooden board. 1955, a dolphin rescued its old enemy, a young tiger shark, which was 1.5 meters long, and lifted it out of the water for eight consecutive days. As a result, this unlucky little shark finally lost his life.

Accordingly, marine zoologists believe that the life-saving virtue of dolphins comes from their "caring nature" for children. It turns out that dolphins are mammals that breathe with their lungs. They can dive into the water when swimming, but they have to put their heads out of the sea to breathe every once in a while, otherwise they will suffocate. Therefore, for newborn dolphins, the most important thing is to reach the surface as soon as possible, but if there is an accident, the dolphin mother's care behavior will happen. She gently lifts the dolphin with her beak, or holds the pectoral fin of the dolphin with her teeth to make it surface until the dolphin can breathe on its own. This caring behavior is the instinctive behavior of dolphins and all whales. This instinct is formed in the process of long-term natural selection, which is very necessary for protecting the same kind and continuing the race. Because this behavior is independent of the object, once the dolphin meets the drowning person and mistakenly thinks it is a floating object, it will also have the same push-pull reaction, thus saving people. In other words, it is a coincidence that the inherent behavior of dolphins coincides with the exciting phenomenon of "saving people".

A wise man in the ocean, a friend of mankind.

Some scientists believe that it is a simplification to attribute the rescue behavior of dolphins to an animal instinct, and its root is to underestimate the wisdom of animals. Oceanographers believe that dolphins have the same learning ability as humans, even slightly better than chimpanzees, and are known as "wise men" in the ocean. Studies show that dolphins are far superior to chimpanzees in both absolute and relative brain weight, and learning ability is closely related to intellectual development. Some people think that dolphins have larger brain capacity than chimpanzees and are obviously animals with high IQ and thinking ability. Its "feat" of saving people is completely a conscious act. Because in most cases, dolphins will push people to the shore, not the sea. At the beginning of the 20th century, near the Atlantic Ocean in Mauritania, there was a poor fishing village, El Mahara. Dolphins in the Atlantic seem to know that people are suffering from hunger, and often drive a large number of fish from the high seas to the port to help fishermen cast nets to catch fish. In addition, anecdotes similar to dolphins helping people fish have also been reported in Australia, Myanmar, South America and other places.

What is the reason why dolphins are so single-minded to humans? In front of sharks, dolphins are crazy killing gods. It is easy to attack humans, but there is no record of dolphins hurting people. The most incomprehensible thing is that even if someone kills a dolphin, the other dolphins present just stand by and never answer blows with blows. For dolphins with strong cooperative spirit, this kind of performance really puzzles zoologists.

Dolphins also have "names"

According to a report by Russian News Network on May 24th, scientists from the University of St Andrews in the United States recently concluded that every dolphin in a social state has its own name, and dolphins in the same group can also distinguish each other's "surnames".

The scientists chose the research site on the Florida coast. During the research, experts recorded and analyzed the sounds made by social dolphins. After that, they separated all the sound signals that can indicate the identity of a specific dolphin, and only kept the frequency characteristics of these sounds.

It is reported that by comparing with the sounds made by people, researchers have separated stress and other characteristics related to "dialogue" from the sounds made by dolphins. During the experiment, the researchers divided the dolphins in the same group into two groups and extracted the sounds made by one group. Later, by playing these sounds to another group of dolphins, people were surprised to find that they actually responded positively to the voices of their "relatives".

Vincent Janick, a scientist who participated in the research, said: "We recorded some dolphin calls in the dry season and input them into the computer to synthesize similar sounds artificially. After that, we played these recordings to the dolphins and observed their reactions. The results show that dolphins can completely tell who made these sounds. "

Based on these observations, scientists have come to the conclusion that dolphins not only have their own names, but also can distinguish their companions according to these names, rather than relying solely on sound. Janick pointed out: "Now we know that dolphins actually have their own names just like us."

Scientists believe that this identification method is very necessary for dolphins-because underwater sounds are easily distorted, and companions can only be identified through more complex sound combinations.

It is reported that 9 of the 14 dolphins who participated in the experiment responded to the "names" of their relatives. However, scientists still don't know why the other five dolphins didn't make any corresponding movements. Maybe they don't want to see their relatives.

Janick said that this discovery is significant because it shows that dolphins have some behaviors similar to ours.

Survival behavior of dolphins

In the wild, dolphins catch prey with their teeth. They have 90 to 100 teeth, but instead of chewing, they swallow the whole fish. Dolphins, like whales, breathe through the pores on their heads, and they swim out of the water to exhale. They will take a deep breath before diving into the water again. Their lungs have a special structure and can quickly decompress, so that they can dive to a water depth of more than 30 meters. Dolphins swim by flapping their tail fins up and down the water. A pair of front fins help them change their swimming direction, and the back fins help them stabilize their bodies. The streamlined body of dolphins can reduce their resistance in the water and enable them to maintain a swimming speed of 30 kilometers per hour.

Dolphins like to eat fish and squid best, and their daily consumption is about 4% to 8% of their body weight. They weigh about 200 kilograms, so they eat about 15 kilograms of food every day. Dolphins living in Ocean Park mainly eat Yokozawa fish, mackerel, sardines, squid and spring fish imported from the United States, because foreign sources are rich and stable, and food is less likely to be contaminated.

Dolphins have no prescribed sleep time. They may sleep during the day or at night. When they sleep, they usually float close to the water, leaving only one side of the brain to rest and the other side to continue to operate, because in the ocean, if they fall asleep, they are easily attacked by the enemy and cannot escape.

Dolphins use high-frequency waves to communicate with their companions. They can make 32 kinds of sounds, and each dolphin has its own special call to identify itself.

Dolphins belong to the suborder Cetacea. All cetaceans have specific sonar systems, among which dolphins are the most sophisticated and can accurately measure the shape of nearby objects by using sound waves? Materials? Location, the whole process only takes 2 seconds.

Although dolphins live in the sea, the water they need for their bodies does not come from the sea, but depends entirely on the water in the fish they eat. If you don't eat fish for more than three days, you will lose water and die. Because dolphins are used to eating live fish in the sea, they can't eat dead fish when they are raised in the sea!

Dolphins often jump across the sea in groups, which is a kind of roll call of dolphins, indicating two signals of "departure" and "home"; And if they keep a certain speed and jump forward regularly, they can also reduce the resistance of water!

If we try to open our eyes in the water, we can't see much; On the contrary, as long as you have a pair of special ears, you can hear clearly in the sea. Dolphins, like their close relatives cetaceans, make strange noises all day, which can spread for several kilometers. This is the language of dolphins. Although it is very complicated, it can achieve good communication effect, so that they can inform their peers or send out distress signals; But also rely on this sonar system to hunt food, such as pleasure fish? Squid, etc ... but sometimes when you meet the beach, ultrasonic misleading is trapped on the beach, which leads to life-threatening.

Killer whale, a bully at sea

There are about 60 species of dolphins in the world, almost all over the ocean. Black whales (killer whales) are a kind of dolphins, and their temperament is very violent. It is said that a killer whale ate 13 dolphins and 15 seals at one time. But their IQ is very high. If raised from a young age, you can cultivate animal stars in the aquatic world!