Sea dolphin. Is a dolphin a fish or a mammal? Dolphin - description and photos. What does a dolphin look like

These marine mammals are the smallest of the cetaceans. Today, scientists have about fifty species of dolphins.

Description

These belong to the subfamily of mammals, the order of cetaceans, the family of dolphins. Their body length ranges from 1.2 to 3 meters, in some species it reaches 10 m. Almost all species of dolphins have a fin on their backs. As well as a muzzle elongated into a “beak” and a huge number of teeth (more than 70).

Dolphins in the sea navigate using echolocation. Animals have very subtle hearing - sound vibrations from several tens of Hz to 200 kHz are available to them.

Dolphins are endowed with complex vocal signaling and a sound signal, echolocation organ located in the nostril (the only one). Associated with it are six air sacs that have a system of muscles. The frequency of the emitted signals is about 170 kHz.

It is necessary to say about the highly developed central nervous system of these animals - large, spherical, its large hemispheres have numerous convolutions (the dolphin's cerebral cortex has 30 billion nerve cells). Such brain sizes allow dolphins to process a large amount of incoming information: they can, like parrots, copy the words that a person says.

The hydrodynamic shape of the body, anti-turbulent properties and the structure of the skin, the hydroelastic effect (adjustable) in the fins, the unique ability to dive to great depths and many other features of dolphins have been of interest to bionics supporters for decades.

These cute animals are kept in many dolphinariums and oceanariums, as they are easy to learn and train. Today, many species of dolphins "work" in the circus. Now the possibility of domestication of certain species of these animals is being considered.

Unfortunately, in many countries they are the subject of fishing (for example, short-headed dolphins in Japan, prodolphins). In our state, the fishing of these animals was banned back in 1966.

The topic of our conversation today is the Black Sea dolphin. We will introduce you to the three main types of these marine life.

bottlenose dolphin or big dolphin

This is the most common and most studied species, which is often kept in the Black Sea aquariums. The bottlenose dolphin is a dolphin that endures captivity more easily than others.

These marine mammals grow up to 3 meters and gain weight of 300 kilograms. This Black Sea dolphin is active during the daytime, it rests at sunset.

Bottlenose dolphins hunt for fish, but they will not refuse shrimps, squids, cephalopods. Hunting for schooling fish, dolphins unite in groups. Looking for stingrays and mollusks, they descend to a depth of more than 300 m.

The bottlenose dolphin is a dolphin that consumes more than 15 kilograms of fish daily. They have few enemies - these are large killer whales and sharks. Humans cause significant damage to the population. In fishing nets, animals often get entangled and die. Echo sounders of sea vessels are also involved in the death of dolphins. The fact is that they are guided by the so-called locator.

Under water, the sounds of dolphins, propagating at high speed, are reflected from objects and come back. Thus, the animal receives information about the object of interest to him. If he feels the "alien" sound wave of the echo sounder, he can get lost in space. Often they jump out onto the shallows. There are many such examples, such cases quite often occur on the routes of sea vessels.

Dolphin sounds

Ichthyologists, studying bottlenose dolphins, found out that they are distinguished by a wide range that they use to communicate within the flock. After analyzing the records of "negotiations", scientists came to the conclusion that there are 17 sounds in the "lexicon" of bottlenose dolphins. When pursuing their prey, they "bark", when they absorb food - "meow", and when they intend to intimidate an opponent, they make sounds resembling claps. Five of them understand the Black Sea dolphins, the common dolphin and the pilot whale. The remaining 12 sounds are completely unique. Trainers claim that various combinations of these signals allow animals to communicate with humans.

bottlenose dolphin breeding

In spring and summer, dolphins have a mating season. At this time, the animals behave completely differently than usual - they bend with their whole bodies, take special poses, sniff each other, jump, stroke each other with their fins and heads, and squeal.

The smallest mature female measured by ichthyologists has a body length of 228 cm. Pregnancy lasts about a year.

The bottlenose dolphin, like most cetaceans, is a viviparous animal. The baby is born in the water, usually tail first. Childbirth sometimes lasts 20 minutes, and sometimes drags on for two hours.

Common dolphin - common dolphin

It is the most of its family. They do not imagine their life alone. A flock of dolphins in some cases reaches two thousand individuals in number.

White flanks create families consisting of several generations of offspring of the same female. Lactating females with young and males sometimes form separate, often temporary schools.

These are the fastest developing speeds up to 60 km / h. Which is easy enough to explain. The dolphin is a small dolphin. The length of his body does not exceed one meter. Even a shark can't keep up with them.

Flocks of dolphins live mainly in the open sea. They feed on fish, mollusks, and sometimes crustaceans.

Habitat

It is generally accepted that this dolphin is from the Black Sea, although it lives in almost all seas and oceans with temperate or warm waters. According to scientists, the common dolphin living in the Black Sea is the standard of "dolphin beauty".

External features

This animal has a proportional, slender body. On the sides there is a rather complex pattern - a horizontal figure eight on a white background, which gave the name to the species. Color - black with white, as well as various shades of gray.

behavior in nature

White flanks are very friendly animals in the same flock. They treat sick dolphins with care, jointly hunt fish, protect and protect young dolphins. Communication in the flock occurs with the help of sound signals - clicks, squeaks and rattles. Unlike the bottlenose dolphin, the common dolphin uses 5 sounds of different frequencies, tonality and timbre.

In winter, dolphins gather in large flocks, reaching several thousand individuals. By the summer, they usually disintegrate, and the white flanks form small groups. In such families there is a very close connection between all its members.

Cases have been recorded of these dolphins helping old animals to float on the surface of the water so that they can breathe.

Dolphin azovka

This variety has several names - Azov dolphin, common porpoise, ingot, Azov porpoise, etc. This is another (of the three most common) Black Sea dolphins.

External differences

The Black Sea Azovka dolphin has a short head with a blunt, rounded muzzle, which has a powerful fat pad. The body of the dolphin has a cigar-shaped shape, a triangular dorsal fin with a wide base. The pectoral fins are slightly rounded. The back is painted dark gray, the belly is almost white. The length of this animal does not exceed 1.8 m. Its weight is 30 kg.

Habitat

Dolphin Azovka occurs off the coast throughout the year, off the coast of Azov appears in early spring. In autumn, these animals leave after schools of atherine and anchovy.

In some years, a sharp cooling and even glaciation of the Sea of ​​\u200b\u200bAzov led to the death of these animals in the ice.

They usually winter near the coast of the Caucasus and the Southern Crimea. These dolphins live in small groups of 5 to 30 individuals, but there are also loners (quite rare).

In summer, you can see Azovka where they hunt for mullet. This dolphin often enters rivers.

Life expectancy - 12 years, puberty occurs by 4 years. Pregnancy lasts approximately 11 months, cubs are born in May-August. The female feeds offspring for 5-6 months.

Azovka feeds on gobies, anchovies, slats and other small fish. Every day, the Azovka dolphin eats more than 5 kg of fish.

Dolphins (Delphinidae) are the most beautiful representatives of CETACEANS WITH AN ELEGANT AND CURVED, LIKE A SPINDLE BODY, WHICH IS ideally adapted for movement in water and ALLOWS IT TO SWIM VERY FAST. BLACK, DARK BROWN or GRAY with white sides and belly. They have very elastic and smooth skin. They practically do not feel the resistance of water due to oily secretions that make it easier for water to glide over the skin. They have a very distinctive muzzle. In some species, it even ends with a real "beak", perhaps a little flattened. The mouth is equipped with many strong teeth - from 80 to 100 on each jaw; with their help, they manage to easily hold food in their mouths. Like all other cetaceans, dolphins need air, so they rise to the surface and breathe, puffing loudly, through the nasal opening - a drawbar located right in the center of the head, and under water it is always closed .
Dolphins are fairly large aquatic mammals, body length from 3 m to 4.20 m. Weight - from 150 to 300 kg. Males are 10-20 cm longer than females. The dolphin lives from 30 to 50 years in natural conditions and 7 years in captivity. The age of puberty is between 5 and 12 years for females and between 9 and 13 years for males. Mating occurs throughout the year, but the most favorable period is from March to August. The male and female each year choose a new partner. The female bears one baby for 12 months, this happens every 2-3 years. The baby is born almost 1 m long. The mother feeds him with very nutritious milk for 6 months. Cubs are born in summer. Females give birth and feed them right in the water. Together with the babies, they swim in the center of the pack so that the males can always protect them.
Dolphins are warm-blooded animals and are able to maintain a constant body temperature. Dolphins feed on a variety of fish (capelin, anchovies, salmon), as well as cephalopods (squid, shrimp). In order to catch the coveted species of fish, some oceanic species of dolphins can dive to a depth of 260 m. They swim very quickly, reaching speeds of up to 40 km / h. Everyone knows the jumping dolphins. Vertically, they are able to jump to a height of up to 5 m, and horizontally - up to 9 m. Dolphins are able to move quickly in the water column due not only to the streamlined shape of the body, but also to the special structure of the fins and skin, which can change with elasticity depending on the density of the water. This allows dolphins to develop maximum speed and catch up with even the fastest inhabitants of the seas and oceans. They are good hunters. With directional echolocation, when a dolphin sends ultrasound to a target, it can easily pinpoint the exact location of its prey. Dolphins also communicate through ultrasound, their hearing is very well developed, so they can talk over considerable distances. In addition to ultrasound, dolphins can make various medium-frequency sounds - squeaks, clicks, whistles, etc. Dolphins are able to quickly dive to great depths, up to 100 m, while they do not have any signs of decompression sickness, like in humans. This is due to the special structure of their circulatory system, the composition of blood and tissues, in which there is a lot of water. When diving, the heart of a dolphin begins to beat very slowly, and when emerging, on the contrary, it starts to beat quickly. They breathe while emerging from the water. Inhalation and exhalation fit within a time of less than 1 s. The respiratory rate in dolphins in 1 min is very rare - only 3-5 breaths and exhalations. During exhalation, air, together with the smallest droplets of water, is thrown out through the drawbar in the form of a powerful fountain of water, beating high up. During sleep, the dolphin swims 50 cm from the surface of the water, surfacing every 30 seconds to take in air. He does this automatically, without even waking up. The dolphin spends its days hunting, playing and "talking" with its fellows. In general, this is a very intelligent and sociable animal. You can often see a dolphin helping a wounded or sick tribesman. He can save a person who has fallen into the water. We even saw dolphins bringing small boats to land, carried by the current far out to sea.
Dolphins do not like loneliness and in the vast majority of cases live in numerous flocks where any action is performed together with their comrades. They do not have a leader. They hunt by attacking entire shoals of fish, and have fun performing their famous jumps one after another. The main enemy of the dolphin is its relative, the killer whale. In some regions, dolphins are still hunted by humans.
Many people believe that there is only one kind of dolphin. In fact, there are about 40 of them, they are all different, and sometimes the differences between them are very significant. The most famous species is the bottlenose dolphin, which can often be seen in the Black and Mediterranean Seas.
Dolphins can be found in almost any sea and ocean in the world. But they prefer the coastal waters of warm seas - in the temperate climate and the tropics. Among dolphins, two species are distinguished by habitat - living in the oceans and living in the seas. They differ mainly in the depth of immersion and food preferences. In our country, dolphins are found in the Black and Baltic Seas.
In the middle of the 20th century a huge number of dolphins lived in the Black Sea. According to rough estimates, the livestock included 2.5 million individuals. But the development of industry, pollution of the sea with sewage led to the gradual extinction of dolphins, since they can only live in clean water. Not the last role in the mass death of dolphins was played by their industrial production. Before the ban on the mass capture of dolphins, it was carried out with the help of special nets that maimed the animals.
Two rare species of dolphins live in the waters of the North Atlantic - white-sided and white-faced.
The white-sided dolphin reaches a length of 2.7 m, with females slightly larger than males. It differs from the white-faced dolphin in shorter pectoral fins and a distinct white stripe on the sides. In the white-faced dolphin, the “Beak” and the front of the “forehead” are white. The body length does not exceed 3 m. The pectoral fins are well developed (up to 0.6 m in length).
White-sided and white-faced dolphins are found mainly in the Barents Sea, sometimes they enter the Baltic Sea. Their number in
Russia has not been established, outside the country they live in the Norwegian and North Seas. The fishery has survived only off the coast of Norway. Both species are protected in Russian territorial waters. The feeding diet of dolphins consists of bottom and bottom fish (cod, flounder, navaga), they feed on mollusks and crustaceans less often. Common dolphins are very fond of accompanying ships. Getting into the flow of water from the ship's propellers, they reach speeds of up to 6 km / h. On the shallows, there are frequent cases of "drying" of white-sided and white-faced dolphins.
During a group drying on the coast of Ireland in 1988, 57 animals died simultaneously. Fishing nets are also dangerous for dolphins, in which they often get entangled and die.
bottlenose dolphin. This large dolphin, distributed throughout the hot and temperate zone, is probably the most studied and tamed, not without reason it plays the role of Flipper. Every day he is entitled to 8-15 kg of fish (anchovies, sardines, mackerel), cuttlefish and squid: after all, 4 m in length! Bottlenose dolphins perfectly get used to captivity, easily learn various tricks and perform in front of the audience with pleasure.
The Black Sea bottlenose dolphin is a medium-sized dolphin (length up to 2.5 m, weight from 150 to 320 kg). It feeds on fish, diving to a depth of 100-150 m and remaining under water for 5-10 minutes. Black Sea bottlenose dolphins keep in small shoals, capable of reaching speeds of up to 40-50 km / h. They tolerate captivity well and are amenable to training.
In the first half of the XX century. Black Sea bottlenose dolphins were numerous in the Black Sea. Severe water pollution and intensive shipping have led to the fact that their numbers in coastal areas have declined sharply. In 1966, the USSR stopped fishing for bottlenose dolphins, then Bulgaria and Romania refused to harvest dolphins. However, despite the long ban, the number of dolphins in the Black Sea is not increasing. The reason, most likely, is the continued fishing in Turkey. At the end of the 80s. 20th century the number of bottlenose dolphins was 35-40 thousand individuals. It is included in the IUCN-96 Red List and Appendix II of the CITES Convention.
The gray dolphin reaches a length of 4.3 m, feeds on cephalopods and is able to stay under water for a long time. In Russian waters, this species is found along the Kuril and Commander Islands. Its number has not been established.
In recent years, a decrease in groups of dolphins near the Kuril Islands has been noted. This, apparently, is associated with their capture in the waters of Japan for keeping in oceanariums. It is included in the IUCN-9c Red List and Appendix II of the CITES Convention.
In the rivers of Asia and South America, and especially in their mouths, there are river, or freshwater, dolphins, which constitute a separate family. River dolphins are the most ancient family of toothed whales. It includes the Gangetic (susuk), Laplatsky, Chinese lake and Amazonian inia. With their long, thin snouts, they dig in the bottom silt, looking for worms and crustaceans. In muddy water, they almost do not need vision, they compensate for it with echolocation. With its help, they can distinguish copper wire with a diameter of 1 mm!
The COMMON DOLPHIN is a cetacean with a strong build and a remarkable coloration: it has a very dark back and a very light belly, and a pattern of light stripes stretches along the sides. Common dolphins, the fastest of cetaceans, feed on schooling fish. Their upper and lower jaws are equipped with sharp and almost indelible teeth.
Killer whale. This large (8-10 m long) dolphin is easily recognizable by its very high dorsal fin (up to 1.8 m in males). The killer whale is called the killer whale. This schooling predator is a thunderstorm of sea birds and animals, especially seals, walruses, dolphins. No animal, not even a huge blue whale, will fight off a flock of these fast, strong cetaceans that can swim at a speed of 55 km/h. There are few teeth in large killer whales, but they are large, and the jaws are equipped with strong muscles.
Grinda (ball-headed dolphin). This dolphin weighs more than 4 tons, body length is about 8 m. It has a spherical outgrowth on its forehead, which increases with age. During the day, the pilot whale sleeps, and at night it dives 30-60 m (sometimes up to 1 km!) To catch octopuses and squids, which it eats 35 kg daily. Under water, the grind is able to do without air for two hours.
Among mammals, cetaceans - whales and dolphins - show the highest degree of adaptation to the aquatic environment. The shape of the body creates perfect streamlining for them. A powerful layer of subcutaneous fat reduces heat transfer and prevents water pressure when animals are immersed to a great depth. The cornea of ​​the eyes is flattened, and Garder's glands, which secrete a specific oily liquid, protect them from the harmful effects of sea water. The entry of water into the respiratory tract (blowhole) is prevented by the mouse's nasal canal system. The larynx is designed in such a way that the trachea and esophagus are isolated from each other. This allows cetaceans to swallow food directly in the water. The inner ear is adapted to the perception of sound and ultrasonic vibrations.
Around a dolphin swimming in a stream of water, there are no turbulences that slow down the movement. Such eddies - turbulent currents - greatly slow down, for example, the movement of submarines with a configuration similar to the body shape of dolphins. "Anti-turbulence" in dolphins is provided by the structure of the skin, which is penetrated by a huge number of passages and tubes filled with a spongy shock-absorbing substance.
The sea turned out to be an exceptionally favorable environment for the development of fine hearing in cetaceans. Sound travels almost 5 times faster in water than in air, and over much greater distances. Many species of toothed cetaceans have sophisticated sonar, allowing them to navigate in the aquatic environment using sound signals. Animals emit specific location sounds and then pick up reflected echoes from various underwater objects. This method of orientation is called echolocation.
The sonar includes mechanisms for transmitting and receiving sound signals. The sonar transmission mechanism is very complex. The main role in it is played by air sacs, which are concentrated in the soft tissues of the head above the bony nostrils. The directionality of the echolocation beam is achieved due to the coordinated work of the air sacs, the nasal canal, the frontal fat pad and a complex system of muscles. The fat pad and the concave surface of the skull focus the emitted signals and send them into space in the form of a beam. Let us assume that the location beam meets a fish on its way. Reflected acoustic beams pass through the skin to the lowest part of the jaw - the bone membrane, then to the intramaxillary fat pad and finally to the ear. The angle at which sound rays strike the mandible is important. Accurate location is achieved if this angle is between 30 and 90°. It is no coincidence that dolphins constantly seem to shake (“scan”) their heads as they approach the object being located.
The principle of operation of the sonar is widely used in modern technology, for example, in sonars and echo sounders.
Dolphins constantly (with a frequency of up to 1000 times per second) make sounds (whistles and clicks) to communicate with their fellows and to navigate in space using echolocation. If such a sound wave stumbles upon an obstacle, then, reflecting from it, it creates an echo that allows the mammal to move in the right direction, go around obstacles, and also find its prey. Dolphins “pronounce” these sounds with their nostrils. They can whistle, bark, meow, squeal, quack, chirp, roar. Some of these sounds correspond to the signals of feeding, anxiety, fear. For example, they have special distress signals when the animal is in danger of suffocating underwater. In this case, the dolphins rush to the aid of a brother in trouble and push him to the surface. Dolphins, placed in two separate pools, between which there is an electronic connection, actively "talk", although they do not see each other. Bottlenose dolphins are able to some extent to imitate the human voice.
All these amazing abilities of dolphins led in the 60s. 20th century American neurophysiologist John Lilly concluded that dolphins have a developed language similar to human speech. Is it so? Human language has two codes - acoustic and semantic (semantic). The first is related to the sound parameters of the word (duration, frequency modulation, etc.), the second is related to semantic characteristics. With its help, a person is able to describe the events of the past, present and future. Neither D. Lilly nor his followers were able to prove that the "language" of dolphins has a semantic code.
The range of sounds emitted by whales and dolphins is unusually large, up to ultrasound. The time between the produced click-signal and the return of its echo tells the animals the distance to any object in their path. The unique echolocation abilities of cetaceans allow them to navigate at night, swim in minefields, determine the depth of the bottom or a submerged object (in some countries they even tried to use dolphins for military purposes). Hearing is best developed in cetaceans, despite their lack of an outer ear. They perceive not only sounds, but also infrasounds (very low sounds) and ultrasounds (very high sounds) that lie beyond the limits of human hearing. Scientists have found that during their travels, whales and dolphins are able to perfectly navigate the sea in any weather - in storm and calm, at depth and at the surface of the water, day and night. It turned out that the so-called analyzers, the sense organs, help them.
At one time, some scientists believed that dolphins could be taught human language, but, unfortunately, this was not achieved. At the same time, during the experiments it turned out that, experiencing different emotions, dolphins make completely different sounds. The study showed that the most important signal for cetaceans is the distress signal. Hearing the voice of a relative in trouble, they immediately rush to help. As a result, the death of one individual often ends in the death of the entire group. The infamous strandings of large groups of whales ashore are the result of the instinct to preserve the species, when, having heard a cry for help, they all rush to save their relative at once.
Dolphins are the best acrobats among marine mammals. They love to jump out of the water, do somersaults in the air, dive again as a “fish” or have fun flipping on their backs. Dolphins can most often be seen in zoos and dolphinariums. He seems cute and smiling because of the special curve of the mouth line.
In ancient Greece, the dolphin was considered a sacred animal; many myths and legends were associated with it.

Dolphins sleep underwater, usually at night, and during the day only after feeding. A weak blow of the hanging tail from time to time exposes the sleeping animal from the water for the next respiratory act. In sleeping dolphins, one hemisphere alternately sleeps while the other is awake. Under water, dolphins navigate primarily with the help of ultrasound in a very wide range - a frequency of up to 170 kHz. The sound signals emitted by them at the level of ultrasound are reflected from possible prey, as well as from obstacles. For humans, these sounds are not audible. Some dolphins, such as the bottlenose dolphin, can imitate the human voice. Between themselves, they "talk" with signals with a frequency of 7 to 20 kHz: whistling, barking (chasing prey), meowing (feeding), clapping (intimidating their relatives), etc.

Dolphins are very fast and jumping animals: for example, bottlenose dolphins can reach speeds of up to 40 km / h, and jump to a height of up to 5 m; The common dolphin swims even faster - at a speed of more than 60 km / h, soars up with a "candle" up to a height of 5 m, and its horizontal jump is 9 m.

Common dolphin or common dolphin (Delphinus delphis)

The common dolphin or common dolphin (Delphinus delphis) has an average length of 2 m, the dorsal fin reaches a length of 30 cm, flippers - 55-60 cm and 15-18 cm (width). The animal's head occupies one-fourth of the entire body. A transverse furrow and a ridge behind it separate a slightly convex forehead from a not too long and straight elongated muzzle, similar to a beak and flattened both above and below. The fusiform body is rather compressed than elongated, its anterior part is round, and the posterior part is slightly compressed from the sides. The narrow and high dorsal fin is sharp at the end with a convex anterior margin and a sickle-shaped posterior margin. The flippers are attached in the first third of the body, the caudal fin is divided into two blunt lobes. The skin is incredibly smooth with a glossy, almost mirror-like surface, it has a greenish-brown or greenish-black color above, and pure white below, the so-called sinuous line separates both colors. On the white side, gray and blackish spots are visible in some places.
The common dolphin lives in the seas of the Northern Hemisphere, it is more playful than other species, and sometimes it swims up rivers. Herds of dolphins can come very close to ships and stay near them for a long time. They constantly dive and rise to the surface, they can expose their top of the head for a while, and then disappear again at a depth. They are very fast swimmers and are able to keep up with even the fastest steamer, while doing various tricks, somersaulting in the water and circling around the ship. One of them can jump out of the water and then fall head first, making almost no noise. White-barreled dolphins form in flocks of 10 to 100 individuals or more. The main feature of their character is sociability, the main reason for which should be considered a lively interest, and not mutual affection. People of ancient civilizations leaned towards the latter statement and praised the affection and mutual love of dolphins. Gesner spoke about this as follows: “Dolphins not only show incredible love for each other, but also for their own cubs, parents, dead comrades, as well as whales and people. The special love of dolphins for cubs is manifested in the fact that after mating, the male and female remain together until their death and are sometimes surrounded by a large family. Dolphin parents reverently raise their children, feed them, sometimes carry them on their “beak”, accompany them everywhere and teach them to get food so that in the future they can survive. When white-barreled dolphins gather in flocks for battle, they leave all the cubs behind them, if everything is calm, then the cubs swim in front, the females follow them, and the males close the flock, who protect them, and even at the last minute will not leave the weakest and defenseless. If the parents become weak and defenseless, then their children will get food for them and help them swim. Common dolphins feed on fish, crayfish, cephalopods and other marine animals. Most of all, they love to hunt for herrings and sardines, and with particular greed they attack flying fish. And the most fierce enemy of this dolphin is not a man, but a predatory killer whale. Because people only chase dolphins if there is no other fresh meat. In addition, a person loves dolphins and prefers to see them as circus performers, rather than food.

more photos of dolphins

What makes dolphins save drowning people

Of course, it is very curious to consider dolphins so merciful (remember the song “and dolphins are kind ...”?), That at the slightest opportunity they will rush to rescue a person in trouble. This opinion is to some extent confirmed by the hypothesis that dolphins were the ancestors of people. After all, these inhabitants of salt water are also mammals and also breathe air. The brain of dolphins is very developed and is almost not inferior to the human brain in terms of the complexity of the device.
Another version explains the dolphin's "kindness" differently and reports that stories about how dolphins saved people are by no means a confirmation of rationality. A number of studies show that this is just a reflex, an instinct developed by dolphins in the process of evolutionary development.
The instinct helps dolphins to survive, to preserve their community, helping out the injured relatives. When a sick or injured mammal, barely afloat, is in sight of its fellows, they begin to support it near the surface of the water. Thus, the dolphin, which could drown and choke, is able to breathe air.
Of course, such behavior is commendable, but it is instinctive and has almost nothing to do with intelligence. After all, it helps the whole species to survive. Confirmation that saving the drowning is not humanism, but only instinct, can be seen in cases where dolphins try to rescue an already deceased relative or person.
We don't mean to offend dolphins or anyone who likes these intelligent marine mammals. We just tried to look at the situation more closely. There is nothing reprehensible in the fact that the reasons that impel to save another being are an instinct akin to the instinct of self-preservation or reproduction.

Dolphins and man

At sea, being on the deck of a ship, one can often see how a flock of several dolphins overtakes the ship. Having developed great speed under water, they simultaneously, as if on command, jump out of the water. After flying several meters through the air, dolphins dive head first into the sea to jump out in a minute.

When you watch how dolphins frolic near the ship, you admire their beauty and dexterity. The power and elegance of the movements of these champions in swimming and jumping among marine animals are striking.

Dolphins live in all seas connected with the ocean, including the Mediterranean, Black, Okhotsk, Japanese, White, Barents. Some freshwater dolphins live in the Amazon, Ganges, and Yangtze rivers.

Scientists number about 70 species of dolphins. Some of them are numerous and live in herds, others are more rare.

An important feature of dolphins is their swift and easy movement in the water. An adult dolphin has a speed of over 50 km/h. With a sudden jump, he throws the body into the air for inspiration. The speed swimming of the dolphin is facilitated not only by the streamlined body, but also by the special properties of the skin.

Dolphins have complex audio signaling. It has been established that they create and perceive ultrasounds. Precise sonar allows them to detect objects the size of an acorn in water at a distance of up to 15 m. Thanks to echolocation, dolphins find food while swimming and avoid collisions with obstacles even in completely muddy water.

The life of dolphins in many ways resembles the life of toothed cetaceans, sperm whales. Like whales, dolphins give birth in the water. At the time of birth, the female raises her tail high above the water, the dolphin is born in the air and manages to inhale the air before falling into the water.

For the first few hours, the baby dolphin swims like a float in an upright position, slightly moving its front flippers: it has accumulated a sufficient supply of fat in the womb and its density is less than that of water.

The female dolphin carries the cub for ten months. It is born half the length of the mother's body. As in the whale, in the dolphin, when sucking, the lips are replaced by a tongue rolled into a tube: it covers the mother's nipple with it, and the mother sprinkles milk into his mouth. All this happens underwater: the respiratory canal of cetaceans is separated from the esophagus, and the dolphin, like whales, can swallow food underwater without fear of choking. Dolphins give birth to one cub every two years. Three years later, he becomes an adult. Dolphins live up to 25-30 years.

Dolphin fishing is currently prohibited. Dolphins are increasingly attracting the attention of scientists. In recent years, abroad and in our country, many articles and books have appeared that amaze readers with sensational information about the extraordinary "mental" abilities of dolphins, about their quick wits.

In the preface to the Russian edition of the book "Man and Dolphin" by the American physiologist J. Lilly, the Soviet zoologist S. E. Kleinenberg writes: ..."

Often they talk about cases of rescue by dolphins of drowning people. In aquariums, dolphins are easily trained to swim up when called and jump through a hoop, play with a ball, and swim with a person. Some reports indicate that dolphins, during long-term experiments in the laboratory, have learned to understand human speech, to carry out, for example, the commands of divers and to bring divers under the water the necessary tool: pincers, hammer, adjustable wrench, search for an object that has fallen into the water, etc. The reliability of such capabilities of dolphins will be shown by further research and scientific experiments.

Dolphin circus performances are shown in many aquariums and dolphinariums, causing great delight of the public. Dolphins jump into papered or burning hoops, play football, move on their tail, ride on the back of a rider, “sing” in front of a microphone, ring a bell, etc.

Of the dolphins, bottlenose dolphins have been better and more fully studied. These dolphins get along easily and even breed in captivity. They are friendly to a person, quickly learn acrobatic stunts, perform many different exercises at the command of a person. In training, according to experts, the bottlenose dolphin is superior to dogs and monkeys.

The Roman naturalist Pliny the Elder, who lived about 2000 years ago, described such a case. In ancient times, a boy from the shores of the Mediterranean taught a bottlenose dolphin to swim at his call, fed him by hand, and she regularly transported him across the bay to school and back home. Something similar happens today. In the town of Opononi (New Zealand), a young female bottlenose dolphin visited the beach, where she played with bathers. There are cases when dolphins drove away sharks from a person who accidentally found himself in the open sea and thus saved him. The attitude of dolphins to sharks is easy to explain: after all, sharks are their natural enemies, they attack dolphins. Therefore, it is impossible to assume that animals consciously seek to help a person: dolphins act as instinct tells them.

Dolphins are useful animals. The inhabitants of Mauritania use them for fishing: dolphins drive red mullet into nets. Trained and released into the sea, dolphins quickly discover fish schools. They can be taught to scout the seabed, deliver soil samples, protect people from sharks, find sunken ships, shells with pearls. Dolphins can learn to detect ships in distress, rescue drowning people. These cetaceans serve as laboratory research subjects for medicine to study cardiovascular disease, the effects of nutrition, and other problems.

These peaceful marine animals require careful and reasonable attitude towards themselves. They are ready to serve people no less diligently than a terrestrial four-legged friend - a dog.

The dolphin is a representative of the suborder of toothed whales, the order of cetaceans, the dolphin family (Delphinidae). The graceful body of the dolphin has a spindle-shaped streamlined shape, which allows these mammals to quickly cut through the water surface. The speed of the dolphin reaches 50 km/h.

Humans and Dolphins

People have known about the extraordinary mind and quick wit of dolphins for a long time. These charming animals rescue people from ships in distress, preventing them from drowning. You could even say that dolphins are the smartest animals on the planet. Many trainers believe that the intelligence of dolphins can be equated to a human, these animals behave so intelligently and unusually.

There is a joke about dolphins, which says that if a person had not overtaken the dolphins and had not climbed down from the tree before, they would come out of the water and now would be the kings of nature, replacing us.

Dolphin is smart, kind, beautiful, he is an excellent student, analyzes, remembers.

Dolphins are directly related to the formidable inhabitants of the oceans, killer whales and whales. There are about 50 species of dolphins. These include the porpoise, black dolphin, gray dolphin, white-faced dolphin, Atlantic white-sided dolphin.

The most popular is the bottlenose dolphin (large dolphin), which people basically have in mind when talking about meetings with representatives of this species. They are well studied and tamed. Bottlenose dolphins are filmed in films, they participate in programs for the rehabilitation of children suffering from various neurological ailments.

Dolphin - description and photos. What does a dolphin look like?

A dolphin is not a fish, but a mammal. Common to all species is an elongated streamlined body, which is crowned by a small dolphin head with a beak-shaped mouth. Each jaw contains 80-100 small conical teeth. The dolphin's teeth are slightly tilted inwards. The transition between the muzzle and the frontal part is well defined. Almost all members of the dolphin class have a prominent dorsal fin. The skin is supple and smooth to the touch. The length of the dolphin can reach 4.5 meters depending on the species.

Dolphins in the water move very easily, they practically do not feel its resistance due to special fatty secretions on the skin that facilitate gliding. Interestingly, the dolphin's skin is quickly erased from the friction of water. Therefore, in the deep skin layers they have a significant supply of regenerating cells. The dolphin constantly sheds, changing up to 25 layers of skin per day!

The eyes of dolphins are small, vision is poor. This is due to the fact that animals practically do not use them for hunting. The nostrils are transformed into a blowhole located on the crown of the head.

How do dolphins breathe?

Whales and dolphins are related and can stay under water for a long time without surfacing. The drawbar is closed during such periods. But, like other cetaceans, dolphins still need air underwater and periodically rise to the surface to breathe.

Do dolphins have ears?

Dolphins have no ears. But that doesn't mean they don't have hearing. There is! True, it functions differently from other mammals. Sounds are perceived by the inner ear, and the air cushions located in the frontal part serve as resonators. But these animals are fluent in echolocation. They accurately determine the location and dimensions of the object by the reflected sound, and by the wavelength - the distance to it.

How Do Dolphins Sleep?

Dolphins also have another interesting physiological feature: they never sleep. Animals hang in the water column, periodically rising to the surface for breathing. During rest, they are able to alternately turn off either the left or right hemisphere of the brain, that is, only one half of the dolphin's brain sleeps, while the other is awake.

Where do dolphins live?

The habitat of the dolphin is exclusively water bodies. The dolphin lives in almost all places on our planet, with the exception of the Arctic and Antarctic regions. Dolphins live in the sea, in the ocean, as well as in large freshwater rivers (Amazonian river dolphin). These mammals love space and move freely over long distances.

Dolphin language

Dolphins are animals social, live in packs, in which there can be from 10 to 100 (sometimes more) individuals, fighting off enemies with common efforts. Inside the pack, there is practically no competition or fights between them; fellow tribesmen coexist peacefully with each other. Dolphins communicate using sounds and signals. Dolphin language extraordinarily varied. The "talk" of these mammals includes clicking, whistling, barking, and chirping. The dolphin voice spectrum extends from the lowest frequencies to ultrasonic. Moreover, they can combine simple sounds into words and sentences, passing information to each other.

What do dolphins eat?

The diet of dolphins includes only fish, preference is given to sardines and anchovies. The method of hunting used by animals is also interesting. A flock of dolphins finds a school of fish and with special sounds forces it to huddle into a dense group. As a result of such hunting, most of the school becomes the prey of dolphins. This feature is often used by gulls, attacking frightened fish from the air. There are known facts when dolphins helped fishermen by driving a joint to them in the net.

Sharks and dolphins

An interesting fact is that sharks and dolphins live in symbiosis. They often hunt together without showing any aggression towards each other.

Dolphin species

There are 17 genera in the dolphin family. The most interesting varieties of dolphins:

• White-bellied dolphin (black dolphin, Chilean dolphin) ( Cephalorhynchus eutropia)

lives exclusively on the coast of Chile. An animal with a rather modest size - the length of the stocky and rather thick body of this cetacean does not exceed 170 cm. The back and sides of the white-bellied dolphin are gray, while the throat, belly area and parts of the flippers adjacent to the body are absolutely white. The flippers and dorsal fin of the white-bellied dolphin are smaller than those of other dolphin species. This species is close to extinction, protected by the Chilean authorities.

• Common dolphin (common dolphin) ( Delphinus delphis)

The length of a marine animal often reaches 2.4 meters, the weight of a dolphin varies between 60-80 kilograms. In the back area, an ordinary dolphin is painted dark blue or almost black, the belly is white, and a spectacular yellowish-gray stripe runs along the light sides. This species of dolphins lives in the waters of the Mediterranean and Black Seas, feels at ease in the Atlantic and Pacific Oceans. There is a common dolphin on the east coast of South America, along the coasts of New Zealand and South Africa, in the seas of Japan and Korea.

• white-faced dolphin ( Lagenorhynchus albirostris)

a large representative of cetaceans with a body length reaching 3 meters and weighing up to 275 kg. A distinctive feature of the white-faced dolphin is a very light, sometimes snow-white muzzle. The habitat of this mammal includes the waters of the North Atlantic, the coast of Portugal and Turkey. The dolphin feeds on fish such as capelin, saffron cod, flounder, herring, cod, whiting, as well as molluscs and crustaceans.

• Large-toothed dolphin ( Steno bredanensis)

The body length of this marine mammal is 2-2.6 meters, weight varies from 90 to 155 kg. The height of the dorsal fin is 18-28 cm. The color of the dolphin is dominated by gray, over which whitish spots are “scattered”. This species of dolphin is common off the coast of Brazil, in the Gulf of Mexico and California, lives in the warm waters of the Caribbean and Red Seas.

• bottlenose dolphin (large dolphin or bottlenose dolphin) ( Tursiops truncatus)

The length of the animal can vary from 2.3 to 3.6 meters, and weight from 150 to 300 kg. The body color of the bottlenose dolphin depends on the habitat, but basically the species has a dark brown upper body and a grayish-white belly. Sometimes there is a weakly pronounced pattern in the form of fuzzy stripes or spots on the sides. The bottlenose dolphin lives in the Mediterranean, Red, Baltic and Black Seas, and is often found in the Pacific Ocean along the coasts of Japan, Argentina and New Zealand.

• Broad-faced dolphin (beakless dolphin) ( Peponocephala electra)

distributed in the waters of countries with a tropical climate, especially mass populations live along the coast of the Hawaiian Islands. The torpedo-shaped, light gray body of the animal is crowned with a cone-shaped dark gray head. The length of a mammal often reaches 3 meters, and an adult individual weighs more than 200 kg.

• Chinese dolphin ( sousa chinensis)

This representative of the genus of humpback dolphins lives in the waters along the coast of Southeast Asia, but migrates during the breeding season, therefore it is found in bays, quiet sea lagoons and even rivers washing Australia and South Africa. The length of the animal can be 2-3.5 meters with a weight of 150-230 kg. Surprisingly, although dolphins are born completely black, as they grow, the body color changes first to light gray, with slightly pinkish spots, and adults become almost white. The Chinese dolphin feeds on fish and shellfish.

• Irrawaddy dolphin ( Orcaella brevirostris)

A distinctive feature of this species of dolphins is the complete absence of a beak on the muzzle and a flexible neck, which received mobility due to several skin and muscle folds behind the head. The color of the body of the Irrawaddy dolphin can be either light gray with a blue tint or dark gray, while the belly of the animal is always a tone lighter. In length, this aquatic mammal reaches 1.5-2.8 meters and weighs 115-145 kg. The dolphin's habitat covers the waters of the warm Indian Ocean, from the Bay of Bengal to the northern coast of Australia.

• Cruciform Dolphin ( Lagenorhynchus cruciger)

lives exclusively in the waters of the Antarctic and subantarctic. The color of the dolphin is black and white, less often - dark gray. A spectacular white marking, covering the sides of the mammal, stretches to its muzzle, framing the eye area. The second mark runs along the back of the body, intersecting with the first and forming an hourglass pattern. An adult cruciform dolphin has a body length of about 2 meters in length, the weight of a dolphin varies between 90-120 kilograms.

• Killer whale (killer whale) ( Orcinus orca)

a mammal that belongs to the dolphin family, a genus of killer whales. The male killer whale has a length of about 10 meters and a weight of around 8 tons. Females are smaller: their length reaches 8.7 meters. Pectoral flippers of killer whales have a wide oval shape. Killer whale teeth are quite long - up to 13 cm in length. The sides and back of the mammal are black, the throat is white, and there is a white stripe on the belly. There are white spots above the eyes. Sometimes completely black or white individuals are found in the waters of the Pacific Ocean. The killer whale lives in all waters of the oceans, except for the Sea of ​​Azov, the Black Sea, the Laptev Sea and the East Siberian Sea.

Dolphin breeding, baby dolphins

Dolphins do not have a pronounced mating season. Reproduction occurs at any time of the year. Mates with females, as a rule, the leader of the pack. Pregnancy lasts approximately 18 weeks and is quite difficult. The female dolphin becomes clumsy, loses the ability to move quickly and often becomes the prey of enemies. The dolphin brings 1 cub about once every 2 years. Small dolphins about 50-60 centimeters long are born right afloat, fully capable and able to follow their mother from the first minutes.

baby dolphins feed on mother's milk, eat frequently and grow rapidly. Feeding stops by one and a half years, when the dolphin begins to feed on fish on its own.

The upbringing and education of babies is carried out exclusively by female individuals. Male dolphins are not caring fathers.

• The level of development of dolphins is extremely high, so they devote a lot of time not only to getting food, but also to communication, games and even sex. These are perhaps the only animals (except humans, of course) whose sexual relations go beyond procreation. These mammals play with great pleasure: dolphins jump out of the water for several meters, just hovering for a moment or making complex figures in the air, pirouettes, screws. Playing dolphins very often attract the attention of ship passengers.
• Unlike fish, the dolphin swings its tail in an up/down direction.
• In the mouth of a sexually mature dolphin, there are 210 sharp teeth, while they play a role only in capturing food, but dolphins swallow their prey without chewing, since they do not have a chewing reflex.
• Dolphins don't sleep! Rather, only one hemisphere of the brain sleeps in them, while the second is awake and intuitively pushes the dolphin to the surface of the water surface to take another breath.
• It is currently forbidden to hunt these interesting and charming animals. Despite all conservation measures, the number of dolphins is declining, and some of them are almost extinct. Now many water parks are working on breeding endangered species, as well as studying and training dolphins.

Each dolphin in the ocean has its own name, to which it responds when called by relatives. He receives it as soon as he is born, and it is a characteristic whistle lasting 0.9 seconds. Dolphins not only call each other by name, but also introduce themselves when meeting strangers. And to identify a relative by voice, without seeing him, is a couple of trifles for them.

Dolphins are mammals from the family of toothed whales of the cetacean order. There are about forty species of these animals on the planet, and you can see them anywhere in the oceans. Most dolphins prefer to live in tropical and subtropical latitudes, but there are those who like colder waters, so they can be seen close to the Arctic, and some species are found both there and there. For example, although the white-faced dolphin lives mainly in the North Atlantic, it can often be seen off the coast of Turkey.

Most members of the family (for example, bottlenose dolphins, white-faced dolphin) are marine inhabitants, but there are four species that prefer to live in fresh river or lake water. The river dolphin lives in Asia, as well as in the waters of the South American rivers of the Amazon and Orinoco.

Unfortunately, if earlier representatives of this family met often, now the river dolphin has practically disappeared and is listed in the Red Book due to habitat loss, environmental pollution, a decrease in the amount of food and small populations.

Description

The length of dolphins ranges from one and a half to ten meters. The smallest dolphin in the world is Maui, which lives near New Zealand: the length of the female does not exceed 1.7 meters. A large inhabitant of the deep sea is considered to be a white-faced dolphin about three meters long. The largest representative is the killer whale: the length of males reaches ten meters.

It is worth noting that males are usually ten to twenty centimeters longer than females (the exception is killer whales - here the difference is about two meters). They weigh on average from one hundred and fifty to three hundred kilograms, killer whale - about a ton.

The back of sea dolphins is gray, blue, dark brown, black and even pink (albino) colors. The front of the head can be either solid or white (for example, a white-faced dolphin has a white beak and front of the forehead).

In some species, the mouth is rounded in front, the beak-shaped mouth is absent. In others, small sizes, the head ends in an elongated mouth in the form of a flattened “beak”, and the mouth is shaped so that people watching them seem to be always smiling, and therefore they often have an irresistible desire to swim with dolphins. At the same time, even a huge number of teeth of the same cone-shaped shape does not spoil the impression - dolphins have about two hundred of them.

Due to the elongated body and smooth, elastic skin, these animals almost do not feel water resistance during movement. Thanks to this, they are able to move very quickly (the average speed of a dolphin is 40 km / h), dive to a depth of about one hundred meters, jump out of the water nine meters high and five meters long.

Another unique feature of these marine mammals is that almost all species of dolphins (with the exception of the Amazonian river dolphin and several other varieties) see well both underwater and above the surface. They have this ability due to the structure of the retina, one part of which is responsible for the image in the water, the other - above its surface.

Since whales and dolphins are relatives, like all representatives of cetaceans, they are quite capable of staying under water for a long period. But, they still need oxygen, so they constantly float to the surface, showing a blue muzzle and replenishing air supplies through a drawbar, which overlaps under water. Even during sleep, the animal is fifty centimeters from the surface and, without waking up, swims out every half a minute.

Way of life

Dolphins live in packs and do not tolerate loneliness very well. Although they do not have a leader, they perform all actions in concert: they hunt together, raise children, have fun, performing jumps of amazing beauty one after another.

The dolphin is considered one of the most intelligent mammals on our planet: the weight of its brain is 1700 grams, which is three hundred grams more than a human, and there are also twice as many convolutions in the cerebral cortex. This explains their highly developed social consciousness, ability to sympathize, readiness to help sick and wounded relatives, as well as drowning people.

Dolphins help quite actively: if one of the members of the flock is injured or barely afloat, they support him near the surface so that he cannot drown and choke. They do the same in relation to a person, helping to get to the shore. Some scientists explain why dolphins do this by caring for the population: each individual in the flock is valuable - and everything must be done to keep it alive.

Language

For communication, animals use gestures (turns, jumps, different styles of swimming, head, fins, tail), as well as voice: the sounds of dolphins are about 14 thousand signals, and everyone has heard about the songs of dolphins. These unique animals are able to perceive the frequency of vibrations up to 200 thousand/sec, while the human ear - up to 20 thousand.

They also have a four times better ability to analyze the sounds of dolphins, separating frequencies from each other (to find out why dolphins have such abilities, there has been a lot of research lately). Communication occurs mainly with the help of ultrasound (it is especially convenient for them to use it to transmit sound over long distances).

The songs of dolphins are not only ultrasound: the sounds of dolphins often sound at an average frequency and are expressed by clicks, squeaks, whistles (studies have shown that they perceive their speech as hieroglyphic pictures).

Dolphin sounds are of two types:

• Sonar or echolocation - animals hear the echo of a beating sound and identify it;
• Whistling or chirping - these sounds of dolphins are used for close communication with relatives and animals express their emotions by them. Scientists have counted about 186 different types of "whistles", which, like human speech, contain sounds, syllables, words, phrases, paragraphs, context and dialect.

Nutrition

The diet of dolphins is based on fish, squid, shrimp (some dolphins in the ocean, in order to catch their favorite prey, are quite capable of diving to a depth of 260 kilometers), killer whales eat marine mammals and birds.

They fish in different ways. Sometimes the whole flock of dolphins is looking for her, sometimes - by a separate group or sent in search of a scout.

If hunting takes place on the high seas, dolphins surround a large school of fish, knocking them into a heap, after which they take turns diving there and feeding. If they fish near the shore, the strategy is somewhat different: a flock of dolphins drives schools to land, after which the fish are easily caught in shallow water.

reproduction

The ability to reproduce in females appears between the fifth and twelfth years of life, in males between the ninth and thirteenth. Their couples are unstable and animals change partners every time.

How long the pregnancy lasts is not precisely established, presumably this period is from ten to eighteen months. When giving birth, the female is very close to the surface, so that, as soon as the baby is born, raise her tail high, giving him the opportunity to take a sip of air before falling into the water.

Usually one baby about half a meter long is born, and up to six months the mother feeds him with milk and protects him. Newborn cubs usually do not fall asleep in the first month of their life and do not allow their mothers to sleep, swimming around them and emerging to the surface every thirty seconds, forcing them to be constantly on the alert.

Relationships with people

Humans and dolphins have a long and complex history: until recently, animals were actively hunted, which led to the complete and partial extinction of some species. After the fishing was banned, the situation improved, but a new trend appeared: to catch these animals for the show (especially since they are very smart and grasp everything on the fly) and giving people far from the sea the opportunity to swim with dolphins. It should be noted that the idea is not the best, because if under natural conditions the inhabitants of the sea live from thirty to fifty years, in captivity - only seven.

Their early death is primarily influenced by a too passive lifestyle, even despite constant training for participation in the show, extremely limited space and the quality of water: the lack of a complete set of nutrients and minerals they need in it.

Recently, people and dolphins have learned to interact better (first of all, this applies to humans, since these animals are sociable, friendly and peaceful). Moreover, communication with these mammals benefits almost everyone: giving the opportunity to listen to the songs of dolphins, chat, stroke the blue back, feed fish, swim with dolphins, psychotherapists and doctors effectively use them to treat diseases in children such as cerebral palsy, early childhood autism, etc.

Dolphins are one of the most mysterious animals on our planet. The intelligence of these marine inhabitants is considered so high that they are called "people of the sea." Scientists say that dolphins are smarter and smarter than all other animals.

Dolphins live in the water, but they are not fish, but mammals from the order of cetaceans. That is, they need air - they breathe with lungs, not gills. People can always see dolphin faces on the surface of the sea because dolphins can stay underwater for about 3-5 minutes on average (although there have been cases where dolphins have been underwater for 10 to 15 minutes). Dolphins feed their young with milk.

Dolphins are found in many seas and oceans of the world, including the Black Sea.
Dolphins live up to 75 years, usually about 50, in captivity usually about 30. With the help of its 88 teeth, the Black Sea dolphin eats about 30 kg of fish per day, the mass of dolphins is up to 500 kg. The body temperature of a dolphin is the same as that of a human, 36.6 degrees. The gestation period for dolphins is about 12 months. The female dolphin usually brings one cub 50-60 cm long and carefully guards it for some time.

At the mention of a dolphin, a person is more likely to imagine a species of bottlenose dolphin (Tursiops truncatus). Bottlenose dolphins owe their popularity in part to their numerous references in cinema and fiction and their high learning ability.

The skin of dolphins is a miracle of nature, they are able to extinguish water turbulences near the surface of a rapidly swimming body, which reduce the speed of movement - submarine designers learned from dolphins, creating artificial skins for submarines. And the feeling of dolphin skin to the touch is quite unusual, and also brings joy: it looks like it is dense, like made of plastic, and when you run it with your palm, it is tender and soft, it seems like thin silk.

When dolphins began to be studied and trained in the middle of the last century, the first results of this work seemed so unusual, and even surprising (they talked about it a lot, wrote about it and made films), that a legend gradually emerged about the unusually high intelligence of dolphins; one could often hear that they are no more stupid than a person, only their mind is different.

The brain of an adult dolphin weighs about 1700 grams, while that of a human weighs 1400. The dolphin has twice as many convolutions in the cerebral cortex. At the same time, there are relatively few neurons in a cubic millimeter of its substance (less than in the brain of primates).

The results of research on the behavior and physiology of the dolphin brain are highly controversial. Some put their learning ability at about the level of a dog and show that dolphins are very far from chimpanzees. On the contrary, studies of dolphin communication methods lead to the conclusion that we have not yet come close to understanding this form of life in natural conditions and it is simply incorrect to compare the level of intelligence of dolphins and chimpanzees. One property of the dolphin brain is quite unique: it never truly sleeps. Sleep - alternately - then the left, then the right hemispheres of the brain. The dolphin needs, from time to time, to float to the surface to breathe. At night, the awake halves of the brain are responsible for this, in turn.

Dolphin language can be divided into 2 groups: Sign language (body language) - various postures, jumps, turns, different ways of swimming, signs given by the tail, head, fins.

The language of sounds (language itself) is a sound signaling expressed in the form of sound impulses and ultrasound. Examples of such sounds can be: chirping, buzzing, screeching, grinding, clicking, smacking, creaking, clapping, squeaking, roaring, screaming, screaming, croaking, whistling.

The most expressive are whistles, of which dolphins have 32 species. Each of them can denote a specific phrase (pain signals, alarms, greetings and a call to me, etc.). Scientists studied the whistle of dolphins using the Zipf method, and obtained the same slope coefficient as that of human languages, that is, they carry information. Recently, about 180 communication signs have been discovered in dolphins, which they are trying to systematize, compiling a dictionary of communication of these mammals. However, despite numerous studies, it has not yet been possible to fully decipher the language of dolphins.

Each dolphin has its own name, to which it responds when relatives address it. This conclusion was reached by American scientists, the results of which were published in the Bulletin of the US National Academy of Sciences (PNAS). Moreover, experts who conducted their experiments in the US state of Florida found that the name is given to the dolphin at birth and is a characteristic whistle.

Scientists caught 14 light gray bottlenose dolphins in the wild with nets and recorded various sounds made by these mammals in the process of their communication with each other. Then, with the help of a computer, “names” were isolated from the records. When a name was "played out" for a pack, a specific individual responded to it. The "name" of a dolphin is a characteristic whistle, the average duration of which is 0.9 seconds.

Everyone has heard that sometimes dolphins and other whales wash ashore. Sometimes this happens due to illness, poisoning or injury. There is another hypothesis explaining the reason for such strange behavior of dolphins: it turns out that with a certain shape of the coast, composed of certain types of precipitation, among the cacophony of sounds generated by the surf, sometimes there is a sound that exactly corresponds to the dolphin's cry for help. Animals, having heard these sounds, instinctively rush to help - and end up on the shore.

Dolphins eat fish. A lot of fish: each member of the flock, per day, must eat 10-30 kilograms. Dolphins are warm-blooded, they need to maintain a high body temperature sometimes in very cold water. The subcutaneous layer of fat also helps this - it acts as a heat insulator and energy source for the intracellular stove: burning fats and carbohydrates with the release of thermal energy. Fuel reserves must be replenished all the time, so they are constantly hunting. They catch up with a flock of fish - no one in the sea swims faster than them, and surround it. If this happens very close to the shore, the dolphins form a half ring and press the fish to the beach; squeezing their hunting formation, they push the fish to the very shallow water and eat it there - while they swim into the very waves of the surf, so shallow that their dorsal fins stick out of the water, and their pectoral fins touch the sand at the bottom.

Having surrounded the school of fish further into the sea, the dolphins do not rush, each separately for prey, but in an organized manner keep the flock in the ring, preventing the fish from dispersing, and plunge into the school one by one. Having caught the prey, they return to their place in the paddock.

Where there are fish, there are dolphins. Near the Black Sea coast, fish are most abundant in spring and autumn - when shoals of mullet, anchovy go for summer feeding in the Sea of ​​\u200b\u200bAzov, or return for wintering in the Black Sea - along the coast of the Caucasus. Therefore, dolphins most often appear here in April-May and in September-October. And in the Kerch Strait itself - the gates of the Sea of ​​\u200b\u200bAzov - hundreds of dolphins stand as an outpost, meeting migrating fish herds.

In summer, it is also not uncommon for bottlenose dolphins to come right up to the beach - more often they can be seen early in the morning or in the afternoon - perhaps because there are fewer swimmers at this time.

Dolphins live in packs in which everyone is relatives, which is why their mutual assistance is so well developed. They always help a weakened dolphin to stay near the surface so that it does not choke; there are stories about how dolphins came to the aid of drowning people. They never act hostile. Dolphins learn tricks very quickly - they only need one correct exercise on a signal, for which they will be rewarded with a fish, so that the skill is fixed in memory. True, they also easily forget their skills if the coach forgets to reinforce a good habit.

Dolphins live for about 30 years. Baby dolphins are born about once every two years. At this time, the dolphin is trying to jump high so that the cub can take its first breath. Dolphins are very touching parents who take care of their cubs for about five years. And even reaching puberty, the cub still remains strongly attached to the mother, and tries to follow her everywhere.

For a long time, scientists were baffled by the question of how dolphins sleep. Indeed, in the sea you can easily drown or become a victim of an attack by other predators. However, now it turned out that the sleep of dolphins is not like the sleep of ordinary animals - during sleep, one hemisphere of the dolphin is resting, and the other is awake. Thus, the dolphin is always in control of the situation and, at the same time, gets a good rest.

Definitely, something makes us treat dolphins differently than other animals - "human friends" ... Friendly, funny, cute ... They are really friendly and curious: they are not afraid to swim up and play with a person, although more often - or not pay attention to people, or simply float away - they have their own worries in the sea. Maybe it's the dolphin's smile? After all, they always smile - so, for some reason, their face is arranged (I don’t even want to call it a muzzle!). And this smile with big eyes - one of those smiles that make us smile involuntarily in response - not all people know how to smile like that.