The common dolphin (or common dolphin) is a mammal belonging to the dolphin family of the suborder toothed whales of the cetacean order.

The barnacles of these animals are called because of the color of the body: a black or dark brown body is painted on the bottom and sides in a bright light color. This contrast in color makes the squirrel the most noticeable among the entire dolphin family. The body length of an adult varies from 1.6 to 2.5 m, weight - 70-110 kg, and the males are only slightly larger than the females.

Common dolphins are slender animals with an elongated head, a prominent forehead and a narrow, long beak. There is a dark triangular fin in the middle of the back. The pectoral fins are narrow and long; they are relatively larger in newborn babies than in mature individuals. The caudal fin has pointed ends and a small notch in the middle.

White barrels are quite fast and frisky creatures: they are able to swim at a speed of 45-55 km / h, while moving they make giant gentle jumps from the water to a height of up to 5 m. Hearing is better developed than sight, since it is of greater importance under water. They have about two dozen sound signals: a whistle, squeak, creak, rattle, etc. At the same time, common dolphins understand the "speech" of other representatives of dolphins: bottlenose dolphins and grind.

The habitat of mammals is separate regions of the World Ocean. Preferring open waters of temperate and tropical latitudes, these representatives of cetaceans are rarely found near the coast. Their large populations live in the east of the Pacific Ocean, in the Black and Mediterranean Seas, as well as in the waters surrounding such territories as North and South America, Korea, Seychelles, Japan, Oman, South Africa, Tasmania, New Zealand, Madagascar, Taiwan and etc.

The main food of these marine inhabitants is pelagic fish that inhabit the upper layers of the seas: sprat, anchovy, horse mackerel, mackerel, herring, anchovy, capelin, mackerel, sardine, mullet and others. Less often, the menu contains shellfish (squid) and crustaceans (shrimp, sea cockroaches).

White barrels breed in the summer months, pregnancy lasts 10-11 months. The baby is born under water, he is born tail first and immediately knows how to swim well. After birth, the mother pushes the baby to the surface of the water so that he can breathe air for the first time. The length of the newborn is 80-90 cm, it feeds on mother's milk for about six months and lives next to the parent for about 3 years.

Common dolphins are intelligent, friendly and sociable animals. They form complex social packs in which there may be a thousand or more individuals. Scientists believe that flocks are made up of families that consist of the offspring of several generations of the same female. Together they hunt for prey, guard young animals, help each other and play. If it is difficult for an old dolphin to stay on the surface, then stronger individuals support him so that he can breathe. They also protect children and pregnant females from attacks by natural enemies: sharks and killer whales.

The shrews treat people peacefully: they never bite or attack. But since these are rather strong animals, while playing with their muzzle or tail, they can, although accidentally, quite noticeably hit a person. Dolphins love to accompany passing ships and passing whales: they frolic in the waves and sharp streams of water they create. Compared to other representatives of their family, the white-barrels tolerate captivity the worst, so it is almost impossible to find them in dolphinariums.

The threat to the health and life of cetaceans is mainly represented by human activity. Pollution of the oceans negatively affects the immune system of dolphins and they are more likely to get sick. Also, unwary individuals fall into the propellers of ships or get entangled in fishing nets. As a trade, these representatives of the fauna were almost never hunted, only Peruvian fishermen killed them in order to sell meat. Now the populations of common dolphins living in the Black and Mediterranean Seas are listed in the Red Book.

Delphinus delphis) - a species of dolphin, a representative of the genus common dolphins (Delphinus).

Appearance

The back of the common dolphin is black or brown-blue in color, the belly is light. It has a stripe on the sides, the color of which changes from light yellow to gray. In general, coloration may vary depending on the region of residence. Having various colors, the common dolphin is one of the most variegated representatives of the order of cetaceans. Its length can reach 2.4 m, and its weight ranges from 60 to 80 kg.

Spreading

The common dolphin is found in different parts of the world's oceans, primarily in tropical and temperate latitudes. Its areas form separate, often unrelated regions. One of the largest areas is the Mediterranean Sea with the Black Sea and the northeast Atlantic Ocean. The common dolphin is the most common member of its family around the European continent. Another large population lives in the eastern Pacific Ocean. In addition, they are found off the east coast of North and South America, off the coast of South Africa, around Madagascar, in the Seychelles, off the coast of Oman, around Tasmania and New Zealand, in the seas between Japan, Korea and Taiwan.

As inhabitants of the open sea, common dolphins are rarely found in the immediate vicinity of the coast. These animals feel most comfortable when the water temperature is from 10 to 25 ° C.

Behavior

Like all dolphins, the common dolphin feeds on fish, sometimes also on cephalopods. It is the most toothed mammal (210 teeth). It is one of the fastest swimming dolphin species and often accompanies ships. Like other species, it forms complex social alliances capable of encompassing more than a thousand individuals. In the summer, these huge groups separate and the dolphins continue to swim in smaller groups. Members of the same group take care of each other. Dolphins were observed to support wounded relatives and carry them to the surface so that they could take in air.

The birth of a young dolphin can take up to two hours. The tail appears first, so that the cub does not suffocate at birth. After birth, the mother carries the cub to the surface so that it can take in air for the first time. During childbirth, the mother animal is protected by the rest of the group from possible shark attacks. Twins are extremely rare and usually do not survive as there is not enough breast milk. Cubs stay for about three years with their mother, of which they feed on milk for about a year.

Population and threats

Taxonomy

When asked how many species belong to the genus Delphinus, there is no definite answer. Most zoologists have always recognized only one species - the common dolphin. Others identified additional species, such as the East Pacific dolphin ( Delphinus bairdii) or dolphin Delphinus tropicalis living in the Indian Ocean. All of them were not officially recognized, although about 20 species were described and proposed.

Since the 1990s, there has been a growing number of zoologists recognizing the second species: Delphinus capensis... It has a longer stigma. Whether it is truly a distinct species, or just a subspecies or variant of the same species, remains a matter of controversy.

In addition to Delphinus delphis delphis itself, a subspecies of the Black Sea common dolphin (Delphinus delphis ponticus Barabash, 1935) is distinguished.

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An excerpt characterizing the Common dolphin

- Eh, you fool, ugh! - said the old man angrily spitting. Some time of silent movement passed, and the same joke was repeated again.
At five o'clock in the evening, the battle was lost at all points. More than a hundred guns were already in the power of the French.
Przhebyshevsky laid down his weapon with his corps. The other columns, having lost about half of the people, retreated in upset, mixed crowds.
The remnants of the troops of Lanzheron and Dokhturov, mingling, crowded around the ponds on the dams and the banks of the village of Augesta.
At 6 o'clock, only at the Augesta dam was still heard the hot cannonade of some Frenchmen, who had built numerous batteries on the descent of the Prazen Heights and fought at our retreating troops.
In the rearguard, Dokhturov and others, gathering battalions, fired back from the French cavalry pursuing ours. It was beginning to get dark. On the narrow dam of Augesta, on which for so many years an old miller with fishing rods sat peacefully in a cap, while his grandson, rolling up his shirt sleeves, fiddled with a quivering silver fish in a watering can; on this dam, along which for so many years the Moravians had peacefully passed on their twin wagons loaded with wheat, in shaggy hats and blue jackets, and, dusty with flour, with white wagons left along the same dam - on this narrow dam now between the wagons and cannons, people disfigured by the fear of death crowded under the horses and between the wheels, crushing each other, dying, walking over the dying and killing each other just to be accurate after walking a few steps. just as killed.
Every ten seconds, blowing air, a cannonball splashed or a grenade exploded in the middle of this dense crowd, killing and spraying blood on those who stood close. Dolokhov, wounded in the arm, on foot with a dozen soldiers of his company (he was already an officer) and his regimental commander, on horseback, were the remnants of the entire regiment. Drawn by the crowd, they pressed into the entrance to the dam and, squeezed from all sides, stopped, because a horse in front of them fell under the cannon, and the crowd pulled it out. One cannonball killed someone behind them, another hit in front and spattered Dolokhov's blood. The crowd desperately advanced, shrank, moved a few steps and stopped again.
Walk these hundred steps, and probably saved; to stand for another two minutes, and, probably, everyone thought he died. Dolokhov, standing in the middle of the crowd, rushed to the edge of the dam, knocking down two soldiers, and fled onto the slippery ice that covered the pond.
- Turn, - he shouted, bouncing on the ice that crackled under him, - turn! He shouted at the weapon. - Holds! ...
The ice held him, but bent and cracked, and it was obvious that not only under the gun or the crowd of people, but under him alone, he would now collapse. They looked at him and huddled to the shore, not daring to step on the ice. The regiment commander, who was on horseback at the entrance, raised his hand and opened his mouth, addressing Dolokhov. Suddenly one of the cannonballs whistled so low over the crowd that everyone bent down. Something plopped into the wet, and the general fell with his horse into a pool of blood. Nobody looked at the general, did not think to raise him.
- Go on the ice! went on the ice! Let's go! turn around! al you do not hear! Let's go! - suddenly after the cannonball that hit the general, countless voices were heard, not knowing what and why they were shouting.
One of the rear guns, entering the dam, crashed onto the ice. Crowds of soldiers from the dam began to flee to the frozen pond. Ice cracked under one of the front soldiers, and one leg went into the water; he wanted to recover and fell to the waist.
The nearest soldiers hesitated, the cannon sled stopped his horse, but shouts were still heard from behind: “Go on the ice, what has become, go! go! " And screams of terror were heard in the crowd. The soldiers who surrounded the gun waved at the horses and beat them to make them roll and move. The horses started to move from the shore. The ice that held the footmen collapsed in a huge chunk, and about forty people who were on the ice rushed forward and backward, drowning one another.
The cannonballs still whistled evenly and flopped onto the ice, into the water, and most often into the crowd that covered the dam, ponds and shore.

On Pratsenskaya Hill, at the very place where he fell with the flagstaff in his hands, Prince Andrei Bolkonsky lay, bleeding, and, without knowing it, moaned with a quiet, pitiful and childish groan.
By evening, he stopped moaning and completely calmed down. He did not know how long his oblivion lasted. Suddenly he again felt alive and suffering from a burning and tearing pain in his head.
"Where is it, this high sky, which I did not know until now and saw today?" was his first thought. Nor did I know this suffering, he thought. - Yes, I didn’t know anything until now. But where am I? "
He began to listen and heard the sounds of the approaching trampling of horses and the sounds of voices speaking French. He opened his eyes. Above him was again the same high sky with floating clouds rising even higher, through which the blue infinity could be seen. He did not turn his head and did not see those who, judging by the sound of hooves and voices, drove up to him and stopped.
The horsemen who had arrived were Napoleon, accompanied by two adjutants. Bonaparte, circling the battlefield, gave the last orders to strengthen the batteries firing at the Augesta dam and examined the dead and wounded who remained on the battlefield.
- De beaux hommes! [Handsome men!] - said Napoleon, looking at the murdered Russian grenadier, who with his face buried in the ground and a blackened back of his head was lying on his stomach, throwing one already numb hand far away.

Common dolphin, or common dolphin. Habitat - open water and coastal area. The convex fat pad in front is clearly delimited by the right and left grooves, converging at an angle at the base of the beak. The dorsal fin is high and slender, sitting mid-length. The pectoral fins are relatively larger in embryos than in adults. The index of distance 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. Body length is about 160-260 cm, but in the Black Sea does not exceed 210 cm. Females are on average 6-10 cm smaller than males. Dolphins are very slender, with a long beak, sharply delimited from the fat pad by grooves. On the palate there are 2 deep longitudinal grooves. The skull is characterized by a very long (1.5-2 times longer than the cerebral box) 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 it diverge much more and cover the bony nostril from the sides.

The species status is common.
The number of groups is 10-500 (1-2000).
The dorsal fin is located 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, below - white; on the sides - with a complex pattern of intermediate tones, namely: two gray elongated fields and 1-3 gray lateral stripes directed from the genital area to the anterior half of the body. A dark stripe runs from the base of the dark pectoral fins to the chin, and a dark stripe runs along the bridge of the nose (from eye to eye, at the front edge of the fat pad). The caudal lobes and dorsal fin are dark. The stripes on the sides of the body are not equally pronounced, but in the Far Eastern white-barrels ( D. d. bairdii) are completely absent (in the latter, the color of the upper part of the body is sharply delimited from the light lower part, without transition tones).


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


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


In the Far East, schooling fish sometimes eats, accumulating together with bottlenose dolphins and short-headed dolphins. In the Mediterranean Sea, in winter, it scares anchovy and sardine from the depths to the surface. Fishermen take advantage of this and deploy nets in places of winter feeding of dolphins, catching fish that have risen. The largest number of empty stomachs in dolphins is observed in summer, which coincides with the height of sexual activity and puppies, when the need for food decreases. The highest fat content in the body of the Black Sea dolphins is observed in March, when the water is coldest, and the lowest in August, at the maximum ambient temperature.


Habitat. The common dolphin is as widespread in the oceans as the bottlenose dolphin, but adheres to the open sea. Occurs from the latitudes of Northern Norway, Iceland, Newfoundland, the southern part of the Kuril ridge, Washington state to the southern latitudes of Tristan da Cunha Island, 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 East - D. d. bairdii Ball, 1873. The first is smaller than the other two, the second is larger than the first, but similar in color, 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 the rostrum width, orbital width and length of the lower jaw.

Pelagic by nature, the common dolphin has a very wide range: from the shores of Norway (Finnmarken Peninsula), Iceland, southern parts of Greenland, Newfoundland, the Sea of ​​Okhotsk and the Bering Sea to the Cape of Good Hope, Tristan da Cunya Island, southern parts New Zealand and Tasmania. Especially abundant in temperate waters of the northern hemisphere (Gulf of Gascon, coast of Brittany, Mediterranean and Black Seas, waters of Nova Scotia, Japan, California, as well as Australia and New Zealand); in small quantities in the tropical zone, where it is known from the shores of Rio de Janeiro, Sierra Leone (West Africa), Jamaica, the Bahamas, the 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; in the Norwegian Sea is small; occasionally penetrates 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 earlier than bottlenose dolphins and porpoises living here.

The Black Sea White Barrel feeds in the upper layer 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 White Barrel gathers in large herds, sometimes together with other species - grinda and short-headed dolphins. He treats a person peacefully, never bites, but does not tolerate captivity.

White-beaked beetles live more often in families, composed, as it is assumed, from 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) schools. During the period of sexual activity, mating groups of sexually mature males and females are also observed. A self-help reaction is developed.

Live up to 30 years. Dolphins navigate the water perfectly with the help of echolocation apparatus, so they can safely frolic even in minefields. Their vision is weaker than hearing and is of lesser importance in water, where the visibility range does not exceed several tens of meters. In the air, dolphins see and respond to hand strokes by closing their eyelids from a distance of up to 2 m. In air, the body temperature of beating dolphins quickly rises from normal (36, ° 5) to 42 °, 6 when heatstroke occurs. However, in water, intense muscle work does not cause an increase in body temperature. Excess heat is released 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 its 6-12 thin-walled veins.

The 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 game of blood vessels, the bundles can either very effectively give off the excess heat brought in by the arterial blood, or drastically reduce the heat transfer by reducing the 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 each time with increased blood flow.

In captivity, common dolphins tolerate bottlenose dolphins and short-headed dolphins worse. As a pelagic species, the common bull rarely dries up on the banks and even less often enters the mouths of rivers. More often than other dolphins are chased by moving vessels. It is possible that the torn edges of the fins and large traces of skin damage are inflicted on the dolphins by the ship's propeller during such a chase. Occasionally, solitary individuals join (apparently during feeding) to herds of other dolphin species, such as the grind.

Sounds, emitted by dolphins are quite varied and have the character of signals. The most frequently heard whistling sound (especially in excited flocks), reminiscent of the squeak of mice. With a thin squeak lasting about 1 sec. air bubbles are released from the spout and rise to the surface of the water. If a squeak is emitted in the air, you can see how the valve of the breathing valve makes a barely noticeable movement with its edges.Of sounds with a frequency of up to 12,000 hertz, squeaks heard during feeding and similar to meowing are recorded on magnetic tape (except for whistling), as well as frequent crackling with a cycle shorter than 0 , 2—0.4 sec., No longer caught by the human ear and intended for echolocation. The sound is delivered by means of air sacs and a sine system, in which resonating frequencies are excited.

Reproduction. In the catches and among the embryos, males predominate numerically (about 53%). The height of mating and puppies is in the summer months, but the breeding season is extended for six months (from May to November). In the Black Sea, females were seen moving away from the shores in front of the puppy in the summer. Childbirth takes place under water (regardless of the weather) and only very rarely can you see the tail of a newborn cub in the vulva of the female when emerging. The newborn immediately swims well. The afterbirth 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 of females - 80-85 cm. Females give birth, apparently, after 1-2 years, after 10-11 months of pregnancy. The possibility of annual birth is evidenced by the frequent findings of small embryos in lactating females. However, the presence of 25% of barren females among those who have already given birth indicates the alternation of three annual puppies 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, and therefore separate from other relatives, moving away from the coast. This is confirmed by observations on the differentiation of schools of dolphins by sex and age. In winter there are two types of shoals - from adult males and from adult females with young growth, and in summer - six types: pre-conceived (pregnant females); children (nursing sleds with cubs); breeding (sexually mature individuals of both sexes with a small part of the suckers who have almost finished their milk supply); immature; remnants (in spring and early summer) of not yet decayed winter schools of males; the same remains of schools of females. The female, judging by the size of the embryo, can mate at least a month before the end of the feeding of the cub, with which the bond is sharply weakened. Mating is accompanied by fights of 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 notion of reaching puberty 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 squirrel) was noted at the age of 6, and the birth at the age of 7. The minimum size of sexually mature females in the Black Sea is 140 cm and males - 150 cm, and the maximum size of immature females is 160 cm and males - 180 cm. All females over 170 cm in length were sexually mature and often had a different number of corpus luteum scars with almost similar sizes. For example, females with a length of 170 and 173 cm had only one scar each, while a female with a length of 175 cm had 15 scars.

Dark V-shaped cape with a drop below the dorsal fin
- the drawing on the sides resembles an hourglass
- white belly and lower part of the 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 (on average, 2.3 mm). The teeth are almost not erased. The greatest condylobasal length of the skull is 485 mm (in the Black Sea, 421 mm).

Fishing. In our country, dolphins are caught with a purse seine in the Black Sea; products are processed at fish factories in Novorossiysk, Tuapse. Anapa and other cities.
The average weight of white barrels is 43-59 kg, of which 29-43% is fat with skin. A young female 143 cm long weighed, according to our data, 32 kg, including (in g) subcutaneous fat 10 980, musculature of the back and tail 6350, spine 2550, ribs with intercostal muscles 1850, fat pad 520, dorsal fin 250, pectorals fins 475, caudal lobes 440, lower jaws 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.) 3913
A substitute for cod fat "dolphinol" is produced from lard; fat is used in the paint and varnish industry, as well as for the lubrication of precision mechanisms, the production of technical machine oil, etc.

Literature:
1. "The life of animals", v. 7 / Mammals / -Edited by V.E. Sokolov.- 2nd ed., Revised.-M .: Education, 1989 - 558 p.
2. Sokolov V.E. Rare and endangered animals. Mammals: Reference manual.-M .: Higher school, 1986.-519 pp.
3. Professor Tomilin Avenir Grigorievich. Cetaceans of the seas of the USSR, 1961

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, as are 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 the animal, which goes back to the ancient Greek language, translates as "newborn baby". With what this is connected, it is difficult to determine now. Perhaps dolphins got such a name for their shrill cry, similar to the cry of a child, or maybe for the resemblance to a human embryo in the womb.

Dolphins are characterized by the presence in both jaws of a rather significant number of homogeneous conical teeth, both nasal openings are usually connected in 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, and there is a dorsal fin. Very mobile and dexterous, voracious predators, living mainly socially, are found in all seas, rise high into rivers, feed mainly on fish, molluscs, crustaceans; sometimes they attack their relatives. They are also distinguished by their curiosity and traditionally good attitude towards 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 coracoid mouth.

Dolphin species

In nature, there are more than seventy species of dolphins. They have species similarities with each other, such as live birth, milk feeding, the presence of respiratory organs, smooth skin and much more. Also, dolphins of different species have their own characteristics. Some animals have an elongated nose, others, on the contrary, are depressed. They can vary in color and body weight.

Common dolphin or the common shrew is one of the most gregarious, frisky and fast-moving cetaceans. Its speed reaches 36 km / h, and when it straddles the ship's wave near the bow of high-speed ships, it is more than 60 km / h. Jumps "with a candle" up to 5 m, and horizontally up to 9 m. It dives for 8 minutes, but usually for a time from 10 seconds to 2 minutes.

The Black Sea White Barrel feeds in the upper layer 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 White Barrel gathers in large herds, sometimes together with other species - grinda and short-headed dolphins. He treats a person peacefully, never bites, but does not tolerate captivity.

White-beaked beetles live more often in families, composed, as it is assumed, from 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) schools. During the period of sexual activity, mating groups of sexually mature males and females are also observed. A self-help reaction is developed.

Live up to 30 years. The sound signals of common barnacles are as diverse as those of bottlenose dolphins: quacking, howling, squeaking, croaking, cat's 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 "rumble" (duration 3 s) were found to have very high sound pressure (from 30 to 160 bar) and a frequency of 21 kHz.

Bottlenose dolphin lives sedentary, or roams in small flocks. The tendency of the bottlenose dolphin to the coastal zone is explained by the bottom feeding nature. For food it dives in the Black Sea to a depth of 90 m, in the Mediterranean - up to 150 m.There is information that in the Gulf of Guinea it dives to 400-500 m.Under experimental conditions in the USA, it dives to 300 m. bottlenose dolphin moves unevenly, in jerks, with frequent sharp turns. Her breathing 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 breathe in captivity 1-4 times per minute, their heart beats 80-140 (on 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.

Bottlenose dolphin skillfully controls a complex vocal apparatus, in which three pairs of air sacs associated with the nasal canal are most essential. To communicate with each other, bottlenose dolphins emit communication signals with a frequency of 7 to 20 kHz: whistling, barking (pursuing prey), meowing (feeding), clapping (intimidating their relatives), etc. creak of rusty door hinges, frequency 20-170 kHz. American scientists recorded 17 communication signals in adult bottlenose dolphins, and in cubs only 6 communication signals. Obviously, the signaling system becomes more complex with the age and individual experience of the animal. Of this number, 5 signals were found to be common for the bottlenose dolphin, grinda, and common barnacle.

Bottlenose dolphins, like all cetaceans, sleep at 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 for 15-30 seconds. A weak blow from the drooping tail from time to time pushes the sleeping animal out of the water for the next breathing act. In sleeping dolphins, one hemisphere alternately sleeps, while the other is awake at this time.

Features of behavior

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 abundant food.

Interesting facts about dolphins include the Gray 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 is contrary to the muscular capabilities of the body. According to the scientist, dolphins need to change the streamlining of their bodies in order to develop a similar speed. The specialists of 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 an absolutely unique hearing. Emitting powerful sound impulses, they are capable of echolocation, which allows them to perfectly navigate in the water, find each other and food.

Dolphins Speech

Dolphins are capable of producing a wide range of sounds through the nasal air sac located under the spihal. There are roughly three categories of sounds: frequency modulated whistles, explosive impulse sounds, and clicks. Clicks are the loudest among marine life sounds.

Dolphins have a sound signal system. Signals of two types: echolocation (sonar), are used by animals to study the situation, detect obstacles, prey and "chirp" or "whistle", for communication with relatives, also expressing the emotional state of the dolphin.

Signals are emitted at very high, ultrasonic frequencies beyond the reach of human hearing. The sound perception of people is in the frequency range up to 20 kHz, dolphins use the frequency up to 200 kHz.

In the "speech" of dolphins, scientists have already counted 186 different "whistles". They have about the same number of levels of organization of sounds as a person: six, that is, sound, syllable, word, phrase, paragraph, 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. It is now used to treat many physical and mental illnesses, including autism, and other ailments. Swimming with dolphins relieves chronic pain, boosts immunity, and even aids speech development in children.

An incredibly romantic fact from the "personal" life of dolphins - ethologists who study Amazon dolphins have found that males give gifts to potential partners. So, what gift is waiting for a female dolphin to consider as a candidate for continuation of the offspring? Of course, a bouquet of river algae!

India became the 4th country to ban captive dolphins. Earlier, Costa Rica, Hungary and Chile took similar measures. The Indians call dolphins "a person or person of a different origin than" homo sapiens ". Accordingly, a “person” must have his own rights, and its exploitation for commercial purposes is legally unacceptable. Scientists analyzing animal behavior (ethologists) say that it is very difficult to determine the line that separates human intelligence and emotions from the nature of dolphins.

Dolphins not only have a "vocabulary" of up to 14,000 sound signals, which 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 the fact that for the sake of entertainment, they can blow air bubbles under the water in the form of a ring 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 communication signals.

Within a flock, dolphins form very close bonds. Scientists have noticed that dolphins take care of sick, wounded and elderly relatives, and a female dolphin can help another female in difficult childbirth. At this time, the dolphins that are nearby, protecting the female in labor, 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 hunting tools. For example, they "wear" sea sponges on their muzzles in order to avoid injury when hunting fish, which can hide in the bottom sediments of sand and sharp pebbles.

The oldest captive dolphin was named Nelly. She lived at Marineland Marine Mammal Park (Florida) and died when she was 61 years old.

When dolphins hunt, they use interesting tactics to trap fish. They begin to circle around the school of fish, close the ring, forcing the fish to stray into a tight ball. Then, in turn, dolphins grab the fish from the center of the school, preventing it from leaving.

Reproduction

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

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

The female dolphin has a baby for ten months. He is born half the length of the mother's body. Like a whale, a dolphin sucking lips is replaced by a tongue rolled into a tube: it covers the mother's nipple, and she sprinkles milk into his mouth. All this happens underwater: the cetacean's respiratory canal 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. After three years, he becomes an adult. Dolphins live up to 25-30 years.

In the temperate and tropical latitudes of the Atlantic and Pacific oceans, such a representative of the dolphin family as the common dolphin lives. It is also called an ordinary dolphin. This species is also found in the Indian Ocean, but there it is relatively rare. But in the Mediterranean and Caribbean seas, it is common. Swims into the Black, Red Sea and loves the waters of the Gulf of Mexico. Sometimes it gets into Norwegian waters and even swims to the Arctic. It prefers open waters, and turns out to be near the coast only from time to time.

Description

The length of representatives of the species varies from 1.6 to 2.4 meters. The mass is 70-100 kg. Some individuals weigh up to 136 kg. Males are longer and heavier than females. The back color can be black or blue-brown. The belly is light. On the sides there is a strip with a non-uniform color. At the beginning of the body, its color can be light gray, yellow or golden, and at the end it is dirty gray. The color of the body is highly dependent on the specific region of habitat. Young dolphins have paler colors than adults.

Reproduction and life expectancy

Males and females reach sexual maturity at the age of 12-15 years. Pregnancy lasts 10-12 months. 1 cub is born with a body length of 70-90 cm and a weight of about 10 kg. The female immediately raises it to the surface of the water for the baby to take the first breath. Milk feeding lasts about a year. At 3 years old, a young dolphin becomes independent. In the sea, the common dolphin lives up to 35 years.

Behavior and nutrition

Representatives of the species live in large groups, which can number hundreds or even thousands of individuals. But such large teams are not a single whole. They are made up of smaller groups with strong social connections. In these small groups, everyone knows each other and is a single family.

Common dolphins swim quickly. They reach speeds of up to 60 km / h. Therefore, they are often accompanied by fast ships. The diet is quite varied. It consists of many species of fish, squid and octopus. All this marine life is harvested at a depth of less than 200 meters. Fish include herring, sardines, anchovies, hake, Atlantic mackerel. The dolphin eats about 10 kg of fish per day.

It should be said that different populations of common dolphins have different status. This is how the Mediterranean population is characterized as endangered. It is currently protected by the Convention on the Conservation of Migratory Species of Wild Animals. This convention is extended to other members of the species living in the Atlantic. In addition, the countries are guided by the Agreement on the Conservation of Small Cetaceans in the North-East Atlantic Ocean and in the Northern Seas.

There is also a Memorandum on the Conservation of Small Cetaceans. They are guided in the waters of Malaysia and West Africa. So in the 21st century, representatives of the species are protected by legislative acts from all sides, and individual problems with numbers should soon disappear.