Photo of a dolphin - the habitat of a common dolphin. Common dolphin Which order does the common dolphin belong to

Delphinus delphis Linnaeus, 1758 Taxonomic position Class Mammalia (Mammalia). Order cetaceans (Balaeniformes). Dolphin family (Delphinidae). conservation status Rare species (3).

area

Tropical and temperate waters of the Pacific, Indian and Atlantic oceans.

Features of morphology

The body length of adult animals is 160–220 cm, coloration with a double light field on the side, expanding towards the ends of the body, the anterior part of this field is often light yellow. The dorsal fin is high, narrow, sickle-shaped; muzzle with elongated long snout. It differs from the bottlenose dolphin in the color of the sides of the body and in small numerous teeth.

Features of biology

Occurs in all Black Sea areas of Crimea and in Kerch Strait. Forms large accumulations in the open sea. It feeds on small schooling fish (hamsa, sprat, horse mackerel). Probable age at sexual maturity is 5–10 years, breeding rates in the Black Sea are unknown.

Threat factors

Deterioration of the food base due to the invasion of the comb jelly Mnemiopsis leidyi and non-compliance by fishermen with the norms of fishing; epizootics of various origins.

Protection measures

It is included in Appendix II of the Berne Convention, Appendix II of the Bonn Convention, Appendix I of the ACCOBAMS Agreement and Appendix II of the CITES International Convention.

Information sources

Barabash-Nikiforov, 1940; Kleinenberg, 1956; Mikhalev, 2008; ChKU, 2009.

Compiled by: Startsev D. B. A photo: Redfern J. (http://commons.wikimedia.org/) (public domain).

Dolphins are marine mammals that belong to the suborder of toothed whales. They are found in the seas and oceans, as well as rivers that have access to the sea. They feed, as a rule, on crustaceans, mollusks, fish, and some do not disdain sea ​​turtles and birds.

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.

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. major inhabitant sea ​​depths is considered to be a white-faced dolphin with a length of about three meters. 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 whale dolphins - 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, the white-faced dolphin has a beak and the front of the forehead white color).

In some species, the mouth is rounded in front, the beak-shaped mouth is absent. In others, small sizes, the head ends with 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. Because of this, they are able to move very quickly ( average speed dolphin is 40 km / h), dive to a depth of about one hundred meters, jump out of the water nine meters in height and five in length.

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.

Dolphin species

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

• White-bellied dolphin (black dolphin, Chilean dolphin) (lat. 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 have grey colour, 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 type close to extinction, protected by the Chilean authorities.

• Common dolphin (common dolphin) (lat. 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. Common dolphin spotted on the east coast South America along the coast of New Zealand and South Africa, in the seas of Japan and Korea.

• White-faced dolphin (lat. Lagenorhynchus albirostris) - a large representative of cetaceans with a body length reaching 3 meters and weighing up to 275 kg. Distinctive feature The white-faced dolphin has 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 mollusks and crustaceans.

• Large-toothed dolphin (lat. 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) (lat. 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) (lat. Peponocephala electra) common in the waters of countries with 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(lat. 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 the countries of 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 (lat. 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 habitat of the dolphin covers the waters of warm indian ocean, starting from the Bay of Bengal and up to the northern coast of Australia.

• Cruciform dolphin (lat. 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) (lat. 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 Sea of ​​Azov, Black Sea, Laptev Sea and East Siberian Sea.

Dolphin Speed ​​Mystery

In 1936, the British zoologist Sir James Gray (Sir James Gray) drew attention to the enormous speed (up to 37 km / h, according to him), which dolphins manage to develop. Having produced necessary calculations, Gray showed that, according to the laws of hydrodynamics, it is impossible to achieve such a high speed with the muscle strength that dolphins possess. This riddle is known as the Gray paradox. The search for its solution to one degree or another continues to this day. AT different time Various research teams have put forward various explanations for the phenomenal speed of dolphins, but there is no unambiguous and universally recognized answer to this question yet.

Ability to regenerate

Dolphins have an incredible ability to heal themselves. In the event of any injury, even big size“They don’t bleed or die from infection, as one might think. Instead, their flesh begins to regenerate at a rapid pace, so that in just a few weeks, a deep wound, such as from a shark's teeth, leaves almost no visible scars. Interestingly, the behavior of injured animals is practically no different from normal. This gives reason to believe that nervous system dolphins is capable of blocking pain sensations in critical situations.

Why don't dolphins freeze underwater?

Finally, let's find out why dolphins, being warm-blooded, do not freeze in water. Their body temperature is 36.6 degrees. AT northern seas Animals need to keep warm. Water, which conducts heat up to twenty-five times more efficiently than air, allows you to freeze much faster than in air.

Why do dolphins do such miracles?! This is due to the large layer of fat under the skin. They can control their circulation and metabolism. This makes it possible to support normal temperature body, according to wikipedia.

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.

How Do Dolphins Sleep?

Dolphins also have another interesting physiological feature A: 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 the right hemisphere of the brain, that is, only one half of the dolphin's brain sleeps, while the other is awake.

How are they born?

Do you know how dolphins are born? The bottlenose dolphin bears a baby for about a year. He is born tail first. The eyes of the cub are immediately open, and the senses are as developed as possible. Moreover, the barely born dolphin already has enough coordination to follow in the footsteps of the mother, who helps to rise to the surface. Then follows the first breath in the life of a baby dolphin. Such trusting relationship in a baby dolphin with a mother, they last approximately 3 to 8 years.

Dolphins and humans: who is smarter?

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. In contrast, studies of dolphin communication methods lead to the conclusion that we have not yet come close to understanding this form of life in vivo and comparing the level of intelligence of dolphins and chimpanzees is simply incorrect.

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 communication

Dolphin language can be divided into 2 groups:

• Sign language(language of the body) - various poses, jumps, turns, various ways swimming, signs given by the tail, head, fins.
• The language of sounds(proper language) - sound signaling, expressed in the form of sound pulses 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, which dolphins have 32 types. 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. AT recent times found in dolphins 180 communication signs who 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.

Dolphin names

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 National Academy US 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

official recognition

The Government of India recently removed dolphins from the animal category and gave them the status of "non-human beings". Thus, India became the first country to recognize the presence of intelligence and self-awareness in dolphins. In this regard, the Ministry environment and Forestry of India have banned any performances using dolphins and called for their special rights to be respected.

1. There are 43 species of dolphins. 38 of them are marine, the rest are river inhabitants.
2. It turns out that in ancient times dolphins were terrestrial, and only later adapted to life in the water. Their fins resemble legs. So our sea friends might once have been land wolves.
3. Images of dolphins were carved in the desert city of Petra, Jordan. Petra was founded as early as 312 BC. This gives reason to consider dolphins as one of the most ancient animals.
4. Dolphins are the only animals whose babies are born tail first. Otherwise, the baby may drown.
5. A dolphin can drown if a tablespoon of water enters its lungs. For comparison, a person needs two tablespoons to choke.
6. Dolphins breathe through an adapted nose, which is located at the top of their head.
7. Dolphins can see with the help of sound, they send out signals that travel long distances and bounce off objects. This allows the animals to judge the distance to the object, its shape, density and texture.
8. Dolphins are superior bats with its sonar capability.
9. During sleep, dolphins stay on the surface of the water to be able to breathe. For control, one half of the animal's brain is always awake.
10. "The Cove" won an Oscar as documentary about the treatment of dolphins in Japan. The film explores the theme of cruelty to dolphins and the high risk of mercury poisoning from eating dolphins.
11. It is assumed that hundreds of years ago, dolphins did not have such an ability to echolocate. It is a quality acquired with evolution.
12. Dolphins do not use their 100 teeth to chew food. With their help, they catch fish, which they swallow whole. Dolphins don't even have chewing muscles!
13. AT Ancient Greece Dolphins were called sacred fish. Killing a dolphin was considered sacrilege.
14. Scientists have found that dolphins give themselves names. Each individual has its own personal whistle.
15. Breathing in these animals is not an automatic process, like in humans. The dolphin's brain signals when to breathe.

Delphinus delphis ( Short-beaked Common Dolphin)

Order Cetaceans - Cetacea

Suborder Toothed whales (Odontoceti)

Dolphin family - Delphinidae

Genus Common dolphins (Delphinus)

Ordinary short-beaked dolphin (Short-beaked Common Dolphin) - the most common species of the dolphin family. Other names: common dolphin, saddleback dolphin, cruciform dolphin.

When asked how many species belong to the genus Delphinus, No unequivocal answer. Most zoologists have always recognized only one species - the common dolphin.

Since the 1990s, there has been a growing number of zoologists recognizing a second species: the long-beaked common dolphin ( ) . It has a longer snout. Is he really separate view or simply a subspecies or variant of the same species remains a matter of controversy.

general information

• View status- widespread.
• habitation- open water and coastal zone.
• Group size- 10-500 (1-2000).
• Location of the dorsal fin- in the center.
• DLina newborn- 80-90 kg.
• adult length- 1.7-2.4 m, males are 6-10 cm larger than females.
• Lifespan- more than 20 years.
• Nutrition- feeds on pelagic schooling fish, as well as cephalopods and rarely crustaceans.
  In the Black Sea, the favorite food is sprat and anchovy, to a lesser extent pelagic needles, haddock, red mullet, horse mackerel, mullet, mackerel.
  In other seas it eats herring, capelin, sardine, saury, mackerel, even flying fish, occasionally cephalopods. At depth - luminous anchovy, hake, batilagus, otophidium, etc.

area

The common dolphin is found in different parts of the world's oceans, primarily in tropical and moderate x latitudes.

Its distribution areas form separate, often unrelated regions. One of the largest areas is the Mediterranean Sea with the Black Sea and the northeast Atlantic Ocean.

Another large population lives in the eastern Pacific Ocean. In addition, common dolphins are found in east coast North and South America, off the coast of South Africa, around Madagascar, off the coast of Oman, around Tasmania and New Zealand, in the seas between Japan, Korea and Taiwan.

Being inhabitants of the open sea, ordinary dolphins are only occasionally found in the immediate vicinity of the coast. These animals feel most comfortable at water temperatures from 10 to 20 ° C.

Number and status

The common dolphin is the most common representative of his family around the European continent.

In the 1960s, their population in the Mediterranean and Black Seas declined sharply, and the reasons for this decline are still unknown. The reason is probably over-intensive fishing, depriving dolphins of food, as well as increasing pollution of the seas, weakening immune system dolphins.

In 2003, the Mediterranean population of common dolphins was estimated to be "endangered" and listed in the Red Book.

Appearance

body length 180-260 cm, weight 75-115 kg.
The physique is slender, fish-like. The snout is narrow.
On each half of the lower jaw 33-67, most often 40-50 conical teeth. There are 2 deep longitudinal troughs on the sky.

The long beak is sharply demarcated from the convex frons. From the side it can be seen that the upper jaw is narrower than the lower. Quite exactly in the middle of the back is a curved triangular dorsal fin, the end of which is slightly extended backwards. The pectoral fins are long and narrow. Light gray side stripes extend from the eyes, which contrast brightly with the dark back when the dolphin jumps out of the water. The pattern on the sides reminds hourglass.

A dark stripe runs from the dark pectoral fins to the chin. Dark circles around the eyes. Caudal fin with a small notch in the middle, with a curved tail edge and pointed ends.

Lifestyle and nutrition

The common dolphin is one of the most gregarious, frisky and fast cetaceans. His speed reaches 36 km / h, and when he rides a ship wave near the bow of high-speed vessels, then more than 60 km / h. Jumps "candle" up to 5 m, and horizontally up to 9 m. It sinks for 8 minutes, but usually for a period of 10 seconds to 2 minutes.

The Black Sea common dolphin feeds in the upper thickness of the sea and does not dive deeper than 60-70 m, but the oceanic form catches fish living at depths of 200-250 m. For food accumulations, the common dolphin gathers in large herds, sometimes together with other species - pilot whale and short-headed dolphins.

White flanks live more often in families, composed, as they say, of the offspring of several generations of the same female. However, males and lactating females with young, as well as pregnant females, sometimes form separate (apparently temporary) shoals. During the period of sexual activity, mating groups of mature males and females are also observed. Mutual assistance developed.

Live up to 30 years. the sound signals of common dolphins are as diverse as those of bottlenose dolphins: quacking, howling, squeaking, croaking, cat cry, but whistling prevails. Up to 19 different signals were counted. This species has unusually strong signals, the meaning of which has not been established, called "shot" (duration 1 s) and "roar" (duration 3 s) turned out to be with very high sound pressure (from 30 to 160 bar) and a frequency of 21 kHz.

Like all dolphins, the common dolphin eats fish, sometimes cephalopods and rarely crustaceans.
In the Black Sea, the favorite food is sprat and anchovy, to a lesser extent pelagic needles, haddock, red mullet, horse mackerel, mullet, mackerel. In other seas it eats herring, capelin, sardine, saury, mackerel, even flying fish, occasionally cephalopods. At depth - luminous anchovy, hake, batilagus, otophidium, etc.

cubs

Breeds predominantly summer.
Pregnancy lasts 10-11 months. The cub feeds on mother's milk for 4-5 months and becomes sexually mature not earlier than in the fourth year, with a length of 1.5-1.6 m.

The birth of a young dolphin can last up to two hours. The rear fin is born first, so that the cub does not suffocate immediately at birth. After birth, the mother brings the cub to the surface so that it can breathe for the first time. During childbirth, the mother animal is protected by the rest of the group from possible attacks by sharks.

Twins are born extremely rarely and, as a rule, do not survive, as there is not enough mother's milk.

common dolphin and human

He treats a person peacefully, never bites, but bad endure adversity.

In some regions of the world, common dolphins have been hunted. For example, they were hunted by Peruvian fishermen to sell their meat. Common dolphins were also hunted in the Black Sea. However, in most parts of the world, these dolphins have never been killed on purpose.

However, they are often killed in fishing nets or caught in ship propellers.

First of all, it must be said that dolphins are not fish, despite the fact that they live in the water. These creatures are mammals and viviparous, just like all the inhabitants of the animal world. In this case, the female gives birth to only one cub, and not many. And the mother bears her child from ten to eighteen months. The name of an animal that goes back to ancient Greek, translates as "newborn baby." What this is connected with is now difficult to determine. Perhaps dolphins got this name for their piercing cry, similar to the cry of a child, or maybe for the resemblance to a human fetus in the womb.

Dolphins are characterized by the presence in both jaws of a fairly significant number of homogeneous conical teeth, both nasal openings are usually connected into one transverse crescent-shaped opening at the top of the skull, the head is relatively small, often with a pointed muzzle, the body is elongated, there is a dorsal fin. Very mobile and agile, gluttonous predators, living mainly socially, are found in all seas, rise high into rivers, feed mainly on fish, mollusks, crustaceans; sometimes they attack their relatives. They are also distinguished by curiosity and traditionally good attitude to a person. In some dolphins, the mouth is extended forward in the form of a beak; in others, the head is rounded in front, without a beak-shaped mouth.

Dolphin species

In nature, there are more than seventy species of dolphins. They have among themselves specific similarities, such as live birth, nutrition with milk, the presence of respiratory organs, smooth skin and much more. Also the dolphins different types have their own characteristics. Some animals have an elongated nose, while others, on the contrary, are depressed. They may differ in color and body weight.

common dolphin or the common dolphin is one of the most gregarious, frisky and fast cetaceans. Its speed reaches 36 km / h, and when it rides a ship wave near the bow of high-speed vessels, then more than 60 km / h. Jumps "candle" up to 5 m, and horizontally up to 9 m. It sinks for 8 minutes, but usually for a period of 10 seconds to 2 minutes.

The Black Sea common dolphin feeds in the upper thickness of the sea and does not dive deeper than 60-70 m, but the oceanic form catches fish living at depths of 200-250 m. For food accumulations, the common dolphin gathers in large herds, sometimes together with other species - pilot whale and short-headed dolphins. It treats a person peacefully, never bites, but does not tolerate captivity.

White flanks live more often in families, composed, as they say, of the offspring of several generations of the same female. However, males and lactating females with young, as well as pregnant females, sometimes form separate (apparently temporary) shoals. During the period of sexual activity, mating groups of mature males and females are also observed. Mutual assistance developed.

Live up to 30 years. The sound signals of common dolphins are as diverse as those of bottlenose dolphins: quacking, howling, squeaking, croaking, cat cry, but whistling prevails. Up to 19 different signals were counted. In this species, unusually strong signals, the meaning of which has not been established, called "shot" (duration 1 s) and "roar" (duration 3 s) turned out to be with very high sound pressure (from 30 to 160 bar) and a frequency of 21 kHz.

bottlenose dolphin lives settled, or roams in small flocks. The tendency of the bottlenose dolphin to the coastal zone is explained by the near-bottom nature of food. It dives for food in the Black Sea to a depth of up to 90 m, in the Mediterranean - up to 150 m. There is evidence that in the Gulf of Guinea it dives to 400-500 m. the bottlenose dolphin moves unevenly, in jerks, with frequent sharp turns. Her respiratory pauses last from a few seconds to 6-7 minutes, up to a maximum of a quarter of an hour. Most active during the day.

Bottlenose dolphins in captivity breathe 1-4 times per minute, their heart beats 80-140 (average 100) times per minute. The bottlenose dolphin can reach speeds of up to 40 km/h and jump to a height of up to 5 m.

The bottlenose dolphin skillfully controls the complex vocal apparatus, in which the most significant are three pairs of air sacs associated with the nasal canal. To communicate with each other, bottlenose dolphins emit communication signals with a frequency of 7 to 20 kHz: whistling, barking (chasing prey), meowing (feeding), clapping (intimidating their relatives), etc. When searching for prey and orienting themselves under water, they emit echolocation clicks resembling creaking rusty door hinges, frequency 20-170 kHz. American scientists recorded 17 communication signals in adult bottlenose dolphins, and only 6 communication signals in cubs. Obviously, the system of signals becomes more complex with age and individual experience of the animal. Of this number, 5 signals were common for bottlenose dolphins, pilot whales, and common dolphins.

Bottlenose dolphins, like all cetaceans, sleep near the surface of the water, usually at night, and during the day only after feeding, periodically opening their eyelids for 1-2 seconds and closing them for 15-30 seconds. 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.

Behavioral Features

An interesting fact is that dolphins use echolocation for hunting. Their hearing is arranged in such a way that animals can determine the number of objects, their volume and the degree of danger from the reflected signal. Dolphins can stun their prey with high frequency sounds, paralyzing them. These creatures hunt only in packs, and they cannot live alone either. Dolphin families sometimes number about a hundred individuals. Thanks to these abilities, the animal is never left without plentiful food.

Interesting Facts from the life of dolphins include "Grey's paradox". James Gray established back in the thirties of the twentieth century that the speed of an animal in water is thirty-seven kilometers per hour, which contradicts the muscular capabilities of the body. According to the scientist, dolphins need to change the streamlining of their body in order to develop a similar speed. Experts from the USA and the USSR puzzled over this issue, but the final decision was never made.

Dolphins have a weak sense of smell, but excellent eyesight and absolutely unique hearing. By emitting powerful sound impulses, they are capable of echolocation, which allows them to navigate perfectly in the water, find each other and food.

Dolphin speech

Dolphins are capable of making a wide range of sounds with the help of a nasal air sac located under the blowhole. There are roughly three categories of sounds: frequency-modulated whistles, explosive impulse sounds, and clicks. Clicks are the loudest among the sounds made by marine life.

Dolphins have a system of sound signals. Signals of two types: echolocation (sonar), used by animals to explore the situation, detect obstacles, prey and "chirps" or "whistles", for communication with relatives, also expressing emotional condition dolphin.

Signals are emitted at very high, ultrasonic frequencies, inaccessible to human hearing. The sound perception of humans is in the frequency band up to 20 kHz, dolphins use frequencies up to 200 kHz.

In the "speech" of dolphins, scientists have already counted 186 different "whistles". They have about the same levels of organization of sounds as a person: six, that is, a sound, a syllable, a word, a phrase, a paragraph, a context, they have their own dialects.

In 2006, a team of British researchers from the University of St. Andrews conducted a series of experiments, the results of which suggest that dolphins are capable of assigning and recognizing names.

Communication with dolphins has a positive effect on the human body, especially on the child's psyche. British experts came to this conclusion back in 1978. Since that time, the development of "dolphin therapy" began. Now it is used to treat many physical and mental illness, including autism, and other ailments. Swimming with dolphins relieves chronic pain, improves immunity and even helps children develop speech.

Incredibly romantic fact from the "private" life of dolphins - ethologists studying Amazon dolphins found that males give gifts to potential mates. So, what gift is the female dolphin waiting for to consider her as a candidate for the continuation of offspring? Of course, a bouquet of river algae!

India has become the 4th country to ban the keeping of dolphins in captivity. Earlier similar measures were taken by Costa Rica, Hungary and Chile. The Indians call dolphins "a person or person of a different origin than" homo sapiens". Accordingly, the "person" must have its own rights, and its exploitation for commercial purposes is unacceptable by law. Animal behavioral scientists (ethologists) say it is very difficult to define the line that separates human intelligence and emotions from the nature of dolphins.

Dolphins not only have a "vocabulary" of up to 14,000 audio signals that allows them to communicate with each other, but also have self-awareness, "social consciousness" and emotional empathy - a willingness to help newborns and the sick by pushing them to the surface of the water.

Dolphins are famous for their playful behavior and for the fact that for the sake of entertainment they can blow air bubbles in the form of a ring under water with the help of a blowhole. These can be large bubble clouds, bubble streams, or individual bubbles. Some of them act as a kind of communicative signals.

Within a pack, dolphins form very close bonds. Scientists have noticed that dolphins care for sick, wounded and elderly relatives, and a female dolphin can help another female with difficult childbirth. At this time, nearby dolphins, protecting the female in childbirth, swim around her for protection.

Another proof of the high intelligence of dolphins is the fact that adults sometimes teach their cubs to use special tools for hunting. For example, they "dress" on the muzzle sea ​​sponges in order to avoid injury when hunting for fish that can hide in the bottom sediments of sand and sharp pebbles.

The oldest dolphin in captivity was named Nelly. She lived in the marine mammal park "Marineland" (Florida) and died when she was 61 years old.

When dolphins hunt, they use an interesting tactic to drive the fish into a trap. They begin to circle around the school of fish, close the ring, forcing the fish to huddle into a tight ball. Then, one by one, the dolphins snatch the fish from the center of the school, preventing it from leaving.

reproduction

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.

Common dolphin, or common dolphin. Habitat - open water and coastal zone. The convex fatty pad in front is clearly demarcated by the right and left grooves, converging at an angle at the base of the beak. The dorsal fin is high and slender, sitting at the middle of the body length. The pectoral fins are relatively larger in embryos than in adults. The distance index from the end of the muzzle to the pectoral fins also decreases with age: 28.5% in newborns and 23% in old ones.

Body type. The body length is about 160-260 cm, but in the Black Sea it does not exceed 210 cm. Females are on average 6-10 cm smaller than males. Dolphins are very slender, with a long beak, sharply demarcated from the fat pad by grooves. There are 2 deep longitudinal troughs on the sky. The skull is characterized by a very long (1.5–2 times longer than the braincase) rostrum, on the palatal side of which there are two (right and left) deep longitudinal grooves. The intermaxillary bones in the middle part are fused with edges; slightly in front, and behind much more strongly diverge and cover the bone nostril from the sides.

The status of the species is widespread.
The number of groups is 10-500 (1-2000).
The location of the dorsal fin is in the center.
The weight of the newborn is unknown. Adult weight - 70-110 kg.
The length of the newborn is 80-90 cm.

Body coloration dark above, white below; on the sides - with a complex pattern of intermediate tones, namely: from two gray elongated fields and 1-3 gray side stripes directed from the genital area to the front half of the body. A dark stripe runs from the base of the dark pectoral fins to the chin and along the bridge of the nose (from eye to eye, in leading edge fat pad) dark stripe. Tail lobes and dorsal fin are dark. The stripes on the sides of the body are not equally pronounced, but in the Far Eastern common flanks ( D. d. Bairdii) are completely absent (in the latter, the coloration of the upper body is sharply delimited from the light lower part, without transitional tones).

Nutrition. Pelagic fish, rarely mollusks and crustaceans. In the Black Sea, the main food items are sprat and anchovy; secondary objects - pelagic needles, haddock, red mullet, horse mackerel, crustacean - sea cockroach Idothea algirica; tertiary objects - mullet, mackerel, bonito, blennies, greenfinches, herring Caspialosa, as well as accidentally falling shellfish and shrimp crangon crangon.

In the diet of non-Black Sea common white flanks, the following were noted: herring, capelin, saury, anchovy, mackerel pike, mackerel, sardines, mullet, Stingray, flying fish, as well (in the Mediterranean and Atlantic Ocean) cephalopods- squids.

On the Far East schooling fish are sometimes eaten, huddled together with bottlenose dolphins and short-headed dolphins. In the Mediterranean Sea, in winter, anchovies and sardines are brought to the surface from the depths. Fishermen take advantage of this and deploy nets in the winter feeding grounds for dolphins, catching fish that have risen. The largest number of empty stomachs in dolphins is observed in the summer, which coincides with the height of sexual activity and puppies, when the need for food decreases. Most content fat in the body of the Black Sea dolphins is observed in March, when the water is the coldest, and the minimum is in August, at the maximum ambient temperature.

Habitats. The common dolphin is as widespread in the world's oceans as the bottlenose dolphin, but sticks to the open sea. It occurs from the latitudes of Northern Norway, Iceland, Newfoundland, the southern part of the Kuril chain, Washington state to the southern latitudes of Tristan da Cunha, South Africa, Tasmania, New Zealand. In this area there are several subspecies, in the waters of our country - 3: 1) Black Sea - D. d. ponticus Barabasch, 1935; 2) Atlantic— D. d. delphis L., 1758 and 3) Far Eastern - D. d. Bairdii Ball, 1873. The first is smaller than the other two, the second is larger than the first, but similar in coloration, and the third is similar in size to the second, but differs from the first two in color, as well as in large indices1 of rostrum width, orbital width, and mandibular length.

Pelagic in nature, the common dolphin has a very wide range: from the coast of Norway (Finmarken Peninsula), Iceland, southern parts Greenland, Newfoundland, the Sea of ​​Okhotsk and the Bering Sea to the cape Good Hope, Tristan da Cunha, southern parts of New Zealand and Tasmania. Particularly numerous in the temperate waters of the northern hemisphere (Gascony Bay, the coast of Brittany, the Mediterranean and Black Sea, waters of Nova Scotia, Japan, California, as well as Australia and New Zealand); are present in small quantities and tropical zone, where it is known from the shores of Rio de Janeiro, Sierra Leone (West Africa), Jamaica, the Bahamas, Gulf of Mexico, India. In the northern hemisphere, it seems to visit higher latitudes than in the southern. In the Barents Sea, it has not been reliably recorded; few in the Norwegian Sea; occasionally enters the Baltic Sea. The Black Sea population of the common dolphin is well isolated, does not migrate through narrow straits to the Mediterranean Sea, and is believed to have appeared in the Black Sea before bottlenose dolphins and porpoises living here.

The Black Sea common dolphin feeds in the upper thickness of the sea and does not dive deeper than 60-70 m, but the oceanic form catches fish living at depths of 200-250 m. For food accumulations, the common dolphin gathers in large herds, sometimes together with other species - pilot whale and short-headed dolphins. It treats a person peacefully, never bites, but does not tolerate captivity.

White flanks live more often in families, composed, as they say, of the offspring of several generations of the same female. However, males and lactating females with young, as well as pregnant females, sometimes form separate (apparently temporary) shoals. During the period of sexual activity, mating groups of mature males and females are also observed. Mutual assistance developed.

Live up to 30 years. Dolphins are excellent at navigating the water with the help of an echolocation apparatus, so they can safely frolic even in minefields. Their vision is less developed than hearing and is less important in water, where the visibility range does not exceed several tens of meters. In the air, dolphins see and react to hand movements by closing their eyelids from a distance of up to 2 m. In the air, the body temperature of beating dolphins quickly rises from normal (36.5) to 42.6 when heat stroke occurs. However, in water, intense muscular work does not cause an increase in body temperature. Excess heat is given off through the surface of the dorsal, caudal and pectoral fins, which are perfect organs for regulating heat. In connection with this function, the blood vessels in the fins have a specific arrangement in the form of bundles, in the center of which there is an artery, and surrounded by 6-12 thin-walled veins.

Vascular bundles, approaching the skin of the fins, break up into smaller and smaller ones, but do not lose their specific structure. With such a device and the presence of a strong vascular play, the bundles can either very effectively give off the excess heat brought by arterial blood, or sharply reduce heat transfer by reducing blood flow to the skin of the fins. Therefore, in living dolphins, one can observe a difference in temperature on the surface of the fins and on the side of the body up to 10-11 °. If there are white spots on the fins, they turn pink every time with increased blood flow.

White-barreled dolphins endure captivity worse than bottlenose dolphins and short-headed dolphins. As a pelagic species, the common dolphin seldom dries up on the shore and even more rarely enters the mouths of rivers. More often than other dolphins are pursued by moving ships. It is possible that the torn edges of the fins and large traces of skin damage are inflicted on dolphins by the propeller of ships during such a chase. Occasionally, single individuals join (apparently during feeding) herds of other dolphin species, such as pilot whales.

sounds, emitted by dolphins are quite diverse and are in the nature of signals. The most common whistle is heard (especially in excited flocks), reminiscent of the squeak of mice. With a thin squeak lasting about 1 sec. air bubbles are released from the blowhole, rising to the surface of the water. If a squeak is emitted in the air, you can see how the blowhole valve makes a barely noticeable movement at the edges. From sounds with a frequency of up to 12,000 hertz, squeaks are recorded on magnetic tape (except for whistling), heard during feeding and similar to meowing, as well as frequent crackles with a cycle shorter than 0 .2 - 0.4 sec., no longer caught by the human ear and intended for echolocation. Sound is produced by means of air sacs and a system of sinuses in which resonant frequencies are excited.

Reproduction. Males predominate in catches and among embryos (about 53%). The peak of mating and puppies falls on the summer months, but the breeding season is extended for six months (from May to November). In the Black Sea was seen in summer time departure of females from the coast before the puppy. Births take place under water (regardless of the weather) and it is only very rarely possible to see the female in the vulva when the tail of the born cub emerges. The newborn immediately swims well. The placenta lingers in the birth canal of the female for up to 1.5-2 hours.

The size of newborn males is 85-95 cm, and females - 80-85 cm. Females give birth, apparently, after 1-2 years, after 10-11 months of pregnancy. The possibility of annual childbirth is evidenced by the frequent findings of small embryos in lactating females. However, the presence of 25% of barren females among those already giving birth indicates an alternation of three annual pups with a fourth, occurring two years later. The lactation period, judging by this frequency, lasts 4-6 months. Milk contains 41.6-43.71% fat, 4.88-5.62% protein, 1.45-1.49% sugar, 0.45-0.46% ash and 48.76-51.62% water.

Females, like bottlenose dolphins, probably protect the cub in the first weeks of its life, in connection with which they separate from the rest of their relatives, moving away from the coast. This is confirmed by observations on the differentiation of dolphin schools by sex and age. In winter, there are two types of shoals - from adult males and from adult females with young animals, and in summer - six types: pre-pregnant (pregnant females); children's (nursing sled with cubs); mating (sexually mature individuals of both sexes with a small part of suckers that have almost finished milk feeding); immature; remnants (in spring and early summer) of not yet disintegrated winter shoals of males; the same remains of shoals of females. The female, judging by the size of the embryo, can mate at least a month before the end of feeding the cub, with which the connection is sharply weakened. Mating is accompanied by fights between males, as evidenced by bite marks, common on the body of adult males, but rare on the skin of females. Only males bite, moreover, most intensively during the period of sexual activity.

The timing of puberty has not been precisely established. The concept of reaching sexual maturity at 2-4 years of age is not supported by the latest data from the Florida Aquarium, where the first mating of the bottlenose dolphin (a species close to the common dolphin) was noted at 6 years of age, and birth at 7 years of age. Minimum size sexually mature females in the Black Sea 140 cm and males - 150 cm, and the maximum size of immature females 160 cm and males - 180 cm. All females over 170 cm long were sexually mature and often had almost similar sizes different amount scars corpus luteum. For example, females with a length of 170 and 173 cm had only one scar each, and a female with a length of 175 cm had 15 scars.

Dark "cape" V-shaped with a drop under the dorsal fin
- drawing on the sides resembles an hourglass
- white belly and Bottom part sides
- all fins are dark
- yellowish spot on the sides
- dark line from pectoral fins to beak
- protruding dorsal fin and beak
- high activity

Teeth. The number of teeth is from 160 to 206, their length is from 4 to 7 mm and the greatest thickness is from 2 to 3 mm (average 2.3 mm). The teeth are almost not erased. The greatest condylobasal length of the skull is 485 mm (421 mm in the Black Sea).

Fishery. We catch dolphins with a purse seine on the Black Sea; products are processed at fish factories in Novorossiysk, Tuapse. Anapa and other cities.
The average weight of white flanks is 43-59 kg, of which 29-43% is lard with skin. A young female 143 cm long weighed, according to our data, 32 kg, including (in g) subcutaneous fat 10,980, muscles of the back and tail 6350, spine 2550, ribs with intercostal muscles 1850, fat pad 520, dorsal fin 250, pectoral fins 475, caudal lobes 440, mandibles 480, tongue 175, brain 670, intestines 967, esophagus 230, liver 596, lungs with larynx 1000, heart 170, both kidneys 186, stomach 198, other parts (blood, skull, etc.) e.) 3913
From fat, a substitute for cod fat "delfinol" is produced; fat is used in the paint and varnish industry, as well as for the lubrication of precise mechanisms, the production of technical machine oil, etc.

Literature:
1. "Life of animals", v. 7 / Mammals / - Under the editorship of V. E. Sokolov. - 2nd ed., Rev. - M .: Education, 1989 - 558 p.
2. Sokolov V.E. Rare and endangered animals. Mammals: Handbook.-M.: Vyssh.shk., 1986.-519 pp.
3. Professor Tomilin Avenir Grigorievich. Cetaceans of the seas of the USSR, 1961