Dolphins of the Black Sea and dolphinariums. Dolphins - who are they? The most interesting facts about dolphins What color do dolphins like

Almost all species of dolphins live in warm salty waters. There are 47 of them in total. These are the indigenous inhabitants of the seas and oceans. But besides marine mammals, there are also river dolphins, representing a separate family, which includes 6 species. These animals live in the rivers of India, China and South America. Their habitat is the Ganges, the Indus and the Brahmaputra in India. In China, they can be found in Lake Dongtinghuv, and in South America they have chosen the Amazon, Orinoco and La Plata for themselves.

river dolphins inferior in size and weight to their marine relatives and have a more primitive brain structure. The body length of these animals usually ranges from 1.5 to 2.5 meters, and the weight is not less than 40 kg, but does not exceed 120 kg. The bodies of river animals are usually brown or almost white, sometimes dark carcasses are also found. The vision of these mammals is very weak or almost completely absent. The most characteristic difference from marine counterparts is the cervical vertebrae. They are not fused into a single bone, as in the ocean inhabitants, but are separated as well as in land mammals.

Dolphins for the most part are heat-loving animals. Cool waters are loved only by certain species. These include striped dolphin. It is common in the North Pacific. It can be found off the coast of Sakhalin and the Kuriles, in the waters adjacent to California and Japan. This mammal reaches a length of 2.2-2.3 meters. The average weight is 140 kg. The maximum weight of males can vary within 180 kg. Females are not lighter than 100 kg.

This is a very lively, fast and energetic dolphin. It can often be seen from the sides of ships. Swift graceful bodies with dark narrow stripes on the sides can accompany the vessel for a very long time. Moreover, the animals swim not only in a parallel course, but also easily overtake the floating facility, cross its path and make various jumps and pirouettes.

The closest relative of the striped dolphin is common dolphin. Along with the shores of Canada, England, Korea and Japan, he also loves the warm waters of the Mediterranean and Black Seas. It can also be found off the coast of Australia, where the animal feels quite comfortable. The dolphin is very graceful and the fastest of all its marine counterparts. In water, it easily develops a speed of 60-70 km / h. Likes to jump. Their height reaches 5 meters.

The coloration of the white flank is very beautiful. The back is black with a greenish tint, and the belly is white. The eyes are rimmed with black circles. In length, the dolphin reaches a maximum of 2.4 meters with an average length of 2 meters. The weight of the animal is about 110 kg. The white-barreled dolphin has a high dorsal fin: its height is 80 cm. These mammals live in large flocks and love to frolic near the water surface.

Dolphin species would lose a lot if among them there was not such a representative as bottlenose dolphin. This is a large mammal, reaching a length of 2.3-3.2 meters. Sometimes there are bottlenose dolphins of more impressive sizes with a body length of 3.6 meters. The mass of this dolphin is usually in the range of 300 kg. The maximum weight reaches 400 kg. The habitat of this animal extends to all temperate and warm waters of the oceans. Bottlenose dolphin can be found in the Black and Mediterranean Seas, in the Indian Ocean, in the Atlantic and in the Pacific, where he loves the waters washing the shores South-East Asia and Australia.

The body color of different individuals is not the same, but varies in shade. A dark brown back and a gray belly predominate. There are animals with a white belly. Sometimes you can meet a representative of the species, in which the whole body has a solid gray color. The speed that the bottlenose dolphin develops in water is 40 km / h. He had a very good and friendly relationship with the man. The dolphin lends itself perfectly to training and even masters some of the words spoken by people. This species most often performs in dolphinariums, striking the audience with its skill.

Without exception, all types of dolphins have one characteristic feature. Sometimes they are in bulk washed ashore and died. Experts explain this phenomenon in different ways. The prevailing point of view is that such suicides are the result of the work of certain brain centers of the animal, directly related to the generation of high-frequency sounds. Sometimes the established frequency of oscillations of the earth's surface resonates as a result of the influence of external oscillatory sources on it. These can be wind, tremors of the earth's crust or the work of ship's radars.

A modified frequency signal can match the sound that an injured dolphin makes. It's like a person who sometimes the howl of a storm outside the window seems like a crying child. Let us recall A. S. Pushkin: “The way she howls like a beast, she will cry like a child.” A nearby flock perceives such a signal as a call for help. She quickly rushes to the coast, is thrown ashore and dies. Similar actions are observed in all marine mammals that do not leave their fellows in trouble (for example, in the same whales), which once again confirms the correctness of this version.

Aquatic mammals of the suborder of toothed whales, closely related to porpoises. Dolphins, like all cetaceans, breathe air, periodically surfacing to take a breath through a single modified nostril - a blowhole located on the crown of the head. They feed mainly on fish and squid, although some species prefer shrimp and other crustaceans, and killer whales also eat sea turtles, aquatic mammals and birds. In most dolphins, males are larger than females and in some species differ from them in a higher dorsal fin. After a gestation period of 12 to 16 months, depending on the species, a single calf is born. The mother feeds him under water with milk for at least six months, and sometimes up to two years, starting to wean from the nipple after 6-18 months. Individuals up to 50 years old are known, although most species have a maximum lifespan of 20-25 years.

Species of the dolphin family (Delphinidae) live in all open seas and sometimes enter the mouths of large rivers. Representatives of the family of freshwater, or river, dolphins (Platanistidae) have a much more limited distribution. For the most part they inhabit inland fresh waters, although some of them can penetrate into brackish estuaries and even into the coastal zones of the seas. The Stenidae family includes species that live in the seas, fresh waters or both of these environments. Outwardly, dolphins differ primarily in their protruding beak, which is clearly delimited from the forehead. The exceptions are several species with a convex, spherical forehead. Depending on the species, dolphins have from 2 to 250 conical teeth. The dorsal fin, if present, is usually sickle-shaped rather than triangular; if it is not bent, then it is very high, like that of a male killer whale. Freshwater dolphins are distinguished by the fact that their neck vertebrae are divided, as in land mammals, and not fused into a single bone. In some species of this family, in addition to conical teeth, there are molar teeth, i.e. close in structure to the indigenous. The dorsal fin is usually very low, in the form of a crest; only in the Laplatian dolphin it is the same as in the dolphins. Most dolphins live in packs and can, like the common dolphin, form huge aggregations. However, usually their groups are small: from 2-3 to about 100 individuals. At least some species seem to have a clear social organization. Dolphins tend to be very active and often swim extremely fast, occasionally jumping out of the water. Some species, such as the long-snouted dolphin, even perform intricate figures in the air, while others like to swing on the waves diverging from the bow of a moving ship. Most dolphins have a wide repertoire of sounds they make. First, these are impulse signals of two main types: echolocation and expressing an emotional state. Secondly, dolphins make monotonous sounds, reminiscent of a whistle. In individuals of some species, its frequency is individual and is used to recognize each other by members of the flock. In addition, the volume and frequency of the whistle reflect the emotional state of the dolphin. In some individuals, auxiliary monotonous signals were noted - also stereotyped and characteristic of each of them. Non-locational impulses, called chirps, fall into many types, which are usually characteristic of a species rather than an individual. Attempts are being made to find a connection between the various chirps and the behavior of the dolphins, but all chirps are for the most part similar to each other and smoothly transition into each other. Although such signals reflect a particular emotional state, it is more understandable to other dolphins than to human observers, and there is no evidence that these sounds actually form a language in human understanding. The same can be said about monotonous whistles.
FAMILY DOLPHIN
This family includes many species of sea dolphins. Below will be considered both some of the most famous and rare of its representatives. Bottlenose dolphins (Tursiops). Of the species of this genus, the most famous is the Atlantic, or simply bottlenose dolphin (T. truncatus), widespread in warm waters around the world. Sometimes several of its subspecies are distinguished, which some scientists consider independent species. Bottlenose dolphins are widely used for research and training. Their body is grayish, up to 3.6 m long (rarely more than 2.4 m in captivity). All bottlenose dolphins feed on fish; on each side of the upper and lower jaws they have approx. 20-25 teeth. Although puberty occurs at 7-8 years, at least males reproduce most actively, becoming about twice as old. Pregnancy lasts about a year, and the pups are breastfed for up to 18 months, although they begin to consume solid food a year earlier. Immediately after birth, the baby himself floats to the surface to breathe air. For the first few months, he stays close to his mother. Her fast swimming does not violate this close physical connection, since the female, by slightly increasing her energy expenditure, generates hydrodynamic forces, with the help of which she ensures the movement of both herself and the cub. Bottlenose dolphins usually migrate in small flocks of less than a dozen individuals, but sometimes several hundred animals can be seen at once. It is these dolphins that most often flash by the beaches, in shallow bays and estuaries, although in cold waters one can often see common porpoises there. In New Zealand, Florida and Scotland, wild bottlenose dolphins have been observed regularly playing with bathers. Such individuals were always found in the same areas and, it seems, were not at all afraid of a person, even allowing themselves to be touched. But such cases are rare. Bottlenose dolphins often ride the waves in front of the bows of sailing ships - usually this is the closest contact with a person that they allow in nature. Sound signals and the ability to echolocate have also been studied mainly in bottlenose dolphins. They also most often tried to attribute the existence of the language, but this hypothesis has not yet been confirmed. The common dolphin (Delphinus delphis) is one of the most common members of the family in the Mediterranean Sea. This is a very beautiful dolphin, with black circles around the eyes and yellow and gray markings on the sides, the pattern of which resembles the letter "X". Sometimes in the open sea you can immediately observe a huge number of these slender, bright animals. White flanks inhabit warm and temperate seas around the world. They are usually divided into three subspecies: one in the Atlantic and, possibly, the Indian Oceans, the other in the Pacific and the third in the Black Sea. Independent, albeit closely related forms are sometimes isolated for South Africa , Japan and the Red Sea. Females of white flanks bring a cub about 3 times in 4 years and feed him for 4-5 months. It is believed that the maximum lifespan of this species is more than 20 years. Short-headed dolphins (Lagenorhynchus) are represented by several species: depending on the classification used, their number can reach up to six. Representatives of this genus usually inhabit colder waters than other dolphins, and some species even reach pack ice. One of them, the Pacific striped dolphin (L. obliquidens), is regularly exhibited in several aquariums and is remarkable for its ability to jump over a high-hanging bar. When short-headed dolphins live with other species of the family, they are very friendly and caring towards other offspring. Their flocks are not as large as those of the white flanks, but sometimes they number up to 1500 individuals. A distinctive feature of the genus is a distinct furrow on the beak, however, it itself is not as long as in many other dolphins, and not as noticeable to the casual observer. As a result, from a distance they can be confused with porpoises. Prodolphins (Stenella) are very diverse in color, number of teeth and other structural features. This is the largest genus of the family in terms of the number of species, and many of them are quite common. Experts believe that the taxonomy of this group is poorly developed. The number of teeth, depending on the species, ranges from 37 to 50 on each side of each jaw. The coloration varies from light spots on a dark background to a similar pattern to the common dolphin, which has a dark back and stripes around the head and on the sides on a light background. Some dolphins are long and slender, with a very elongated snout, while others have a more massive body and a much shorter snout. Most species live far from shore in tropical and temperate waters around the world. They are good swimmers and often ride the waves in front of ships. The Atlantic spotted dolphin (S. plagiodon) and its close eastern Pacific relative S. graffimani are sometimes shown in aquariums. The first species is a spectacular jumper, often jumping over the head of the person feeding it. In captivity, dolphins feed on fish, but in nature their favorite food is squid. The striped prodolphin (S. caeruleoalba) is a commercial species in Japan; sometimes it is shown to the public. Grinds, or ball-headed dolphins (Globicephala), are a very large species: animals reach a length of 6.5 m and a mass of approx. 2 t. They are characterized by a huge pillow on the forehead containing viscous fat. The body is black with a white mark on the chest and the same line below the middle of the belly. This pattern, as well as the light "saddle" on the back behind the dorsal fin, typical of some forms, is not always distinct. There are three types. Pilot whales usually live in warm and temperate waters, but in summer they can enter relatively cold areas. It has been proved that they have seasonal migrations performed by flocks of up to several hundred individuals. All of them often move forward, synchronously emerging and sinking, as if at the command of the leader. Apparently, packs sometimes stop to rest, but even then their formation usually remains militarily correct, and the animals float to the surface to take a breath in the same synchronous manner as during movement. Sometimes whole flocks of pilot whales are thrown onto land and die. The reasons for this behavior are unknown. Pilot whales feed almost exclusively on squid, but in captivity their diet may include fish. Females usually reach sexual maturity at 6-7 years old, and males sometimes only by 12 years. Pregnancy lasts approx. 16 months Although the calf can eat solid food from 6 months of age, milk feeding continues until 2 years of age. The killer whale (Orcinus orca) is the largest and beautiful view dolphins, characterized by a bright black and white pattern; their mass is up to 8 tons. This species inhabits all seas, from the coldest to the warmest, keeping mostly close to the coast. This is the only cetacean that, in addition to fish, feeds on aquatic mammals, sea turtles and birds. The killer whale is characterized by pronounced sexual dimorphism. Males reach a length of 9 m - a meter and a half more than females. In addition, their dorsal fin is high and almost straight, while in adult females it is about half as long and curved. Unlike most dolphins, killer whale pectoral flippers are not pointed, crescent-shaped, but wide and paddle-shaped. These animals are very voracious and hunt in packs, attacking not only small animals, but also huge baleen whales, from whose body they tear out pieces of meat. In addition to warm-blooded, killer whales eat a large number of fish, which actually forms the basis of their diet. Despite the bad reputation of these animals, called "killer whales", there is no convincing evidence of their attacks on humans. On the contrary, in captivity killer whales are very docile and allow people to ride on their backs, and the trainer can fearlessly stick his head into their open mouth. They lend themselves perfectly to training, are able to almost completely jump out of the water and perform complex sets of exercises. The small, or black, killer whale (Pseudorca crassidens), with large sharp teeth, is very similar to the common killer whale, and resembles a pilot whale in size and color, differing in a much more streamlined body shape. There is no record of attacks by this species on warm-blooded marine animals, but its way of feeding is unusual: the little killer whale often grabs very large fish and tears them apart in much the same way as an ordinary killer whale tears seals, small dolphins or porpoises. Like pilot whales, these animals sometimes wash ashore. The gray dolphin (Grampus griseus) is very similar in appearance to the pilot whale, but differs in the presence of teeth, usually only on the lower jaw, a deep furrow on the forehead and a large number of scars scattered throughout the body. Males have especially a lot of them: it is believed that in most cases these are traces of battles with relatives. The markings are so characteristic that they used to be mistaken for part of the gray dolphin's natural pigmentation. This species feeds mainly on squid and lives in all seas except polar ones.
Other dolphins. The dolphin family includes many rare or little-known species. The pygmy killer whale (Feresa attenuata) looks very similar to the small one, but much smaller. It lives only in the South Pacific, off the coast of Japan and Senegal, and is rarely kept in captivity. The Irrawaddy dolphin (Orcaella brevirostris) has two subspecies. One lives in the Irrawaddy River in Burma, and the other in the seas from the Bay of Bengal to Borneo and Java. Beakless, or broad-faced, dolphin (Peponocephala electra) is found in the tropical waters of the Atlantic, Pacific and Indian oceans. There are two species of whale dolphins (Lissodelphis) deprived of dorsal fins: the northern one (L. borealis) is noted in the northern part of the Pacific Ocean, and the southern one (L. peroni) - in the temperate zone of the Southern Hemisphere. The genus of beak-headed, or motley, dolphins (Cephalorhynchus) includes several southern, mainly cold-water species. They are small in size, characterized by a bright black and white color. The Sarawak dolphin (Lagenodelphis hosei) is known from only one skeleton found on the island of Borneo.
FAMILY STENIDAE
There is no Russian name for the Stenidae family. It includes both freshwater and marine forms with characteristic structural features of the respiratory tract. Large-toothed dolphins (Steno) are a monotypic genus. Its only species, the comb-toothed dolphin (S. bredanensis), is widely distributed in temperate and tropical seas, where it occurs only far from the coast. Its snout is long, but not as sharply demarcated from the forehead as in most dolphins, but rather blending smoothly into the top of the head. The dark gray color of the back gradually lightens on the sides and becomes completely light on the belly. The species got its name because of the teeth with a ribbed, uneven surface. The biology of the animal is little studied, but it is known that it feeds on fish, squid and octopuses. Although these dolphins are considered a rare species, significant numbers are occasionally caught in the Hawaiian Islands region to study vocalizations and local migrations. Like representatives of the dolphin family, they emit both monotonous whistles and various impulse signals. The genus Sousa includes five species that live off the coast of West and South Africa, China, Borneo and the Indian Ocean. By appearance these are typical dolphins with a snout quite clearly delimited from the forehead. Little is known about their biology. They feed mainly on fish, live mainly in the sea, but near the coast and can enter rivers. The Chinese white or humpback dolphin (S. chinensis) lives mainly in fresh waters. Long-beaked dolphins (Sotalia) are two species. Both are found in South America, but in different ecological niches. The Guianan dolphin (S. guianensis) inhabits coastal sea waters and estuaries in northeastern South America from Rio de Janeiro to Venezuela. The Amazonian dolphin, or tukashi (S. fluviatilis), lives only in the fresh waters of the Amazon basin and often swims into the flooded jungle during floods. Long-billed dolphins feed on fish, but the details of their biology are still little known.
FAMILY OF FRESHWATER, OR RIVER, DOLPHINS
This family consists of four genera, one species each. Three of them are exclusively freshwater. The fourth, South American, species lives in estuaries and in winter months may migrate along seashores. Amazonian inia, or bouto (Inia geoffrensis). Young animals are light gray, but gradually acquire a pinkish tint with age. Their very long snout is covered with stiff hairs or bristles, apparently performing a sensory function. Amazonian inias have an average of 25-27 teeth on each side of each jaw. The front teeth are pointed, conical, and the back teeth are somewhat similar to the molars. Two types of teeth and unfused cervical vertebrae are primitive features for cetaceans. Inya feeds on fish, including those covered with bony plates, and her teeth are often heavily worn, apparently due to chewing solid food. According to some reports, inia may have several subspecies. These freshwater cetaceans are common in the Amazon and Orinoco basins, and during floods even penetrate into flooded forests, where they swim between trees. Looking out for food at the bottom, the ini often turn upside down, perhaps because otherwise their thick cheeks interfere with the view. Studies of the sounds they make have shown the presence of a rich repertoire of impulse signals, including echolocation signals used for searching for food and research. environment; however, no monotonous whistles were found. The Gangetic dolphin, or susuk (Platanista gangetica), lives in the Indian rivers Indus, Ganges and Brahmaputra. Obviously, he is blind, since his eyes are devoid of a lens. However, animals compensate for this shortcoming by developing an unusual cup-shaped depression in the skull that resembles an enlarged flashlight reflector and undoubtedly directs and concentrates echolocation signals. Studies of several living specimens of this species have demonstrated their apparently exceptional echolocation abilities. It is believed that the Gangetic dolphin feeds on freshwater shrimp and silt-burrowing fish, which it catches by probing the bottom with its very long jaws. Surprisingly, this animal usually swims on its side. The Chinese lake dolphin (Lipotes vexillifer) lives in the central-eastern part of China in the Yangtze (Changjiang) and Qiangtang rivers, as well as the Dongting and Poyang lakes. For a long time, this species was assigned to the family Platanistidae, but now it is often isolated into an independent family Lipotidae. The animal reaches a length of 2.5 m, and the weight of one of the studied specimens was 160 kg. In appearance, it is closest to the Amazonian inia. Chinese lake dolphins feed on fish, in particular catfish, which they pull out of the bottom silt with their long beak. They usually move in pairs, forming a larger group of about ten individuals. The Laplata dolphin (Pontoporia [] blainvillei) is unique among the species of the family Platanistidae for several reasons. It lives not only in the large La Plata River in South America, but also exits it into purely marine coastal waters. Some features of its skeleton and a good development of the dorsal fin are also unusual. Some taxonomists have proposed placing it in the Delphinidae family. This small dolphin feeds on fish, shrimps and cephalopods.
See also cetaceans.

Collier Encyclopedia. - Open Society. 2000 .

See what "DOLPHINS" are in other dictionaries:

- (Delphininae), a subfamily of dolphins. Most have a dorsal fin, the muzzle is extended into a "beak", the teeth are numerous (more than 70). 50 species, 20 genera: sotalii, stenella, common flanks (unity, VID), cetacean D., short-headed D., beak-headed D. ... Biological encyclopedic dictionary

DOLPHINS, a family of toothed whales. Length 1.2 10 m. Over 50 species, mainly in moderately warm, including fresh (river dolphins), waters. Most are fast-swimming (up to 55 km/h) herd animals. When searching for prey and orienting under ... ... Modern Encyclopedia

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

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

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

Common dolphin or common dolphin (Delphinus delphis)

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

more photos of dolphins

What makes dolphins save drowning people

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

Dolphins and man

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The dolphin is a mobile and agile predator, a social animal that lives in all seas, rises high along the rivers, feeds on fish, mollusks, and crustaceans. Dolphins are distinguished by their curiosity and good attitude towards people. Dolphins swim very fast, their flocks often accompany ships. Since ancient times, the dolphin has become a favorite and popular animal: legends, poems and stories were composed about it, sculptures were made. The term "dolphin" is of Greek origin and goes back to the words "bosom" and "womb". It is assumed that it can be interpreted as a "newborn" (according to its external resemblance to babies or the similarity of the calls of dolphins and children).

All species of dolphins have a naked streamlined body, flexible and muscular, with highly modified fin limbs, a small head with a sharp snout and a dorsal fin. The head is distinguished by a pronounced transition between the forehead and nose. The eyes are small, vision is poor. There are no tactile vibrissae and no sense of smell. The dolphin's nostrils are a single breathing hole located on the crown of the head, which allows the animal to breathe even when almost completely submerged under water. Dolphins don't have ears. The hearing of the animal is provided by the inner ear, and the air cushion in the frontal lobes. Dolphin echolocation is perfect. It picks up reflected sound waves and determines the location of environmental objects, the distance to them and their nature (density, structure, materials). That is, in fact, the dolphin sees the world through sounds. The dolphin itself makes sounds: crackling, clicking, clattering, chirping. All these sounds are diverse and complex, used for communication. A dolphin has 40-60 teeth, small and uniform.

The body of the dolphin is naked, the structure of the skin reduces the friction of water and improves hydrodynamic qualities. Due to the mobility of the animal, the outer layer of the skin wears out quickly: during the day, on average, 25 cell layers of the skin are replaced. There are two color options for dolphins: plain (gray, black, pink) and contrasting, black and white.

The diet of the dolphin consists only of fish, small and medium (anchovies, sardines). The dolphin is characterized by a unique fishing technique. At first, the herd explores the water with the help of echolocation, if a school is found, the dolphins approach it, making sounds at a special frequency that causes panic in the fish. The fish, in turn, stray together, thanks to which the dolphins catch it with a common effort. At the same time, they exhale air, creating a kind of barrier around the fish, and catch most of the school. Interestingly, gulls and boobies track the behavior of dolphins from the air and join their meals.

The habitat of dolphins is quite wide, including almost the entire planet. They are not found only in the cold waters of the Arctic and Antarctic. Basically, dolphins inhabit the seas and oceans, some species - large rivers. Dolphins prefer open spaces, roam freely in the oceans, and can come close to shores.

Common Dolphin Species

Common dolphin (Delphinus delphis L.) - body from above and fins are grayish or greenish-black, belly is white, skin is smooth and shiny. Body length about 2 m, dorsal fin 80 cm high, width of pectoral fins 15-18 cm, length 55-60 cm. It lives in the seas of the northern hemisphere, lives in flocks of 10, 100 and up to 1000 individuals.

Bottlenose dolphins (Tursiops truncatus) are a well-known and popular dolphin species that lives all over the globe. The body is dark, gray or brown above, lighter below. In length from 2 to 4 m, weighs 100-300 kg.

Dolphins do not have a distinct sexual dimorphism. Males and females are similar in appearance, only the former are usually slightly larger in size.

Dolphins are highly developed social animals. They are distinguished by a friendly disposition, peaceful relations in packs, where fights do not occur, and there is no fierce competition. The pack is led by an experienced leader. Dolphins communicate with each other using a variety of sounds, each member of the flock has its own individual voice. Dolphins have different signals to warn of danger, the presence of food, or to express a desire to play. From simple sounds, a dolphin is able to compose a complex, and even a whole sentence, which is very reminiscent of speech. Dolphins are recognized as highly developed animals, and their intelligence is equal to great apes.

Dolphins breed throughout the year. They do not have special mating rituals, the male leader mates with the female while moving, and even the birth of a cub occurs “on the go”. The baby is born tail first and is immediately able to independently swim behind the mother to the surface for the first breath. The mother helps him by pushing him up with his nose. At first, the baby is fed with mother's milk, but rather quickly switches to adult food and an adult lifestyle.

The main enemies of the dolphin are sharks and related species such as the large dolphin. Since ancient times, people have also hunted dolphins, but not on an industrial scale, since a dolphin can become a maximum source of meat, and even then not the best palatability. For this reason, dolphins were hunted by the inhabitants of the north and sailors.

Certain species of dolphins are currently endangered, mainly due to death in fishing nets, oil spills, wounds from ship propellers (for example, the New Zealand subspecies of Hector's dolphin (Cephalorhynchus hectori maui, for which less than 150 individuals have been recorded). dolphins are also kept in water parks, where after a complex training program, animals participate in entertainment shows.

One of the methods of modern psychotherapy - dolphin therapy, is built on the communication of people with dolphins. It is carried out as communication, play and simple joint exercises under the supervision of specialists. The method is used to treat children with cerebral palsy, early childhood autism, attention deficit hyperactivity disorder, and also to relieve contractions during childbirth.
In the United States, there are special combat dolphins trained for military purposes. They are capable of detecting underwater mines, rescuing sailors after the destruction of a ship, and finding enemy combatants. The dolphins helped search for sunken missile launchers, anti-submarine missile warheads and training mines, sometimes doing better than divers. In the middle of the last century, the US Navy was accused of training dolphins to harm people, deliver weapons, etc., but all such accusations were refuted.
One of the most popular entertainments since the last century has become dolphinariums - special aquariums where trained dolphins are shown to the audience. Mostly killer whales and bottlenose dolphins. These smart and friendly animals are highly trainable and can perform complex and beautiful numbers, which are well-deserved love of thousands of spectators around the world.

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 the animal, which dates back to the ancient Greek language, is translated 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 dexterous, voracious predators, living mostly 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 a 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 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 s and closing them for 15-30 s. 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 the "Grey 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. Emitting powerful sound impulses, they are capable of echolocation, which allows them to perfectly navigate in the water, find each other and food.

Dolphin speech

Dolphins are capable of emitting wide range 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. There are two types of signals: echolocation (sonar), used by animals to study the situation, detect obstacles, prey, and “chirps” or “whistles”, for communication with relatives, also expressing the emotional state of the 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 diseases, 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 they 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” sea sponges on their muzzles in order to avoid injury when hunting for fish that can hide in 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.