Black Sea white sided. Common dolphin or common dolphin

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

These animals are called white-sided because of their body color: the black or dark brown body is colored below and on the sides in a bright light color. This contrast in color makes the common dolphin 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, with males only slightly larger than females.

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

Squirrels are quite fast and playful creatures: they are capable of swimming at a speed of 45-55 km/h, while moving, making giant gentle jumps from the water to a height of up to 5 m. Hearing is developed better vision, since it has greater significance underwater. Sound signals they have about two dozen: they are whistling, squeaking, creaking, grinding, etc. At the same time, white sideds understand the “speech” of other representatives of dolphins: bottlenose dolphins and pilot whales.

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

The main food of these sea creatures– pelagic fish inhabiting the upper layers of sea waters: sprat, anchovy, horse mackerel, mackerel, herring, anchovy, capelin, mackerel, sardine, mullet and others. Less common on the menu are shellfish (squid) and crustaceans (shrimp, sea cockroaches).

White sideds breed in summer months, pregnancy lasts 10-11 months. The baby is born underwater, it 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 a newborn is 80-90 cm, it feeds on mother's milk for about six months and lives next to its parent for about 3 years.

Common dolphins are intelligent, friendly and sociable animals. They form complex social flocks that can number a thousand or more individuals. Scientists believe that flocks are made up of families, which consist of the offspring of several generations of one female. Together they hunt for prey, protect the young, help each other and play. If an old dolphin has difficulty staying on the surface, stronger individuals support him so that he can breathe. They also protect children and pregnant females from attack. natural enemies: sharks and killer whales.

White sideds are peaceful towards people: they never bite or attack. But since these are quite 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 they create and sharp currents of water. Compared to other representatives of their family, white sideds tolerate captivity the worst of all, so they are almost impossible to meet in dolphinariums.

The threat to the health and life of cetaceans comes mainly from human activity. Pollution of the World Ocean negatively affects the immune system of dolphins and they get sick more often. Also, careless individuals fall into the propellers of ships or become entangled in fishing nets. These representatives of the fauna were almost never caught as a fishery; only Peruvian fishermen killed them for the purpose of selling meat. Now the populations of common dolphins living in the Black and Mediterranean Seas are listed in the Red Book.

Common dolphin, or common dolphin. Habitat - open water And coastal zone. 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 in the middle of the body length. The pectoral fins of embryos are relatively larger than those of 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.

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

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

Body coloring dark above, white below; on the sides - with a complex pattern of intermediate tones, namely: two gray elongated fields and 1-3 gray side stripes directed from the genital area to the anterior half of the body. From the base of the dark pectoral fins to the chin there is a dark stripe and along the bridge of the nose (from eye to eye, at leading edge fat pad) dark stripe. Tail blades and dorsal dark. The stripes on the sides of the body are not equally sharply expressed, but in the Far Eastern white sided ( D. d. bairdii) are completely absent (in the latter, the color of the upper part of the body is sharply separated from the light lower part, without transitional tones).

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

The diet of non-Black Sea white drums included: herring, capelin, saury, anchovy, mackerel, mackerel, sardines, mullet, stingray, flying fish, and also (in the Mediterranean Sea and Atlantic Ocean) cephalopods - squids.

On Far East sometimes eats schooling fish, congregating together with bottlenose dolphins and short-headed dolphins. In the Mediterranean Sea in winter, it flushes anchovies and sardines from the depths to the surface. Fishermen take advantage of this and deploy nets in the winter feeding areas of dolphins, catching the rising fish. Largest quantity Empty stomachs in dolphins are observed in the summer, which coincides with the height of sexual activity and puppies, when the need for food decreases. Highest body fat content black sea dolphins observed in March, when the water is coldest, and the minimum in August, when maximum temperature environment.

Habitats. The common dolphin is distributed in the world's oceans as widely as the bottlenose dolphin, but adheres to open sea. Found 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 Eastern - D. d. bairdii Ball, 1873. The first is smaller than the other two, the second is larger than the first, but is similar to it in color, and the third is similar in size to the second, but differs from the first two in color, as well as large indices1 of the width of the rostrum, orbital width and length of the lower jaw.

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

The Black Sea common dolphin 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. When gathering food, the common dolphin gathers in large herds, sometimes together with other species - pilot whales and short-headed dolphins. It treats humans peacefully, never bites, but does not tolerate captivity well.

White sideds often live in families, which are supposed to be composed of the offspring of several generations of the same female. However, males and lactating females with young animals, 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. Mutual assistance reaction has been developed.

They live up to 30 years. Dolphins are excellent at navigating in water using their echolocation apparatus, so they can frolic safely even on minefields. Their vision is less developed than hearing and is less important in water, where the visibility range does not exceed several tens of meters. In the air, dolphins see and react to hand waves by closing their eyelids from a distance of up to 2 m. In the air, the body temperature of struggling dolphins quickly rises from normal (36.°5) to 42°.6, when heat stroke occurs. However, in water, intense muscular work does not cause an increase in body temperature. Excess heat is given off through the surface of the dorsal, caudal and pectoral fins, which are perfect heat regulating organs. In connection with this function, the blood vessels in the fins have a specific structure in the form of bundles, in the center of which there is an artery, and surrounded by 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 this arrangement and the presence of strong vascular play, the bundles can either very effectively release excess heat brought by arterial blood, or sharply reduce heat transfer by reducing blood flow to the skin of the fins. Therefore, in living dolphins, one can observe a difference in temperature on the surface of the fins and on the side of the body of up to 10-11°. If there are white spots on the fins, they turn pink each time with increased blood flow.

Common dolphins tolerate captivity worse than bottlenose dolphins and short-headed dolphins. As a pelagic species, the white drum rarely dries out on the shore and even more rarely enters river mouths. More often than other dolphins, they are chased by moving ships. It is possible that the torn edges of the fins and large traces of damage to the skin are caused to the dolphins by the propellers of the ships during such a chase. Occasionally, single individuals join (apparently during feeding) pods of other dolphin species, such as pilot whales.

Sounds, sounds made by dolphins are quite varied and are in the nature of signals. The most common sound heard is whistling (especially in excited flocks), reminiscent of the squeaking of mice. With a thin squeak lasting about 1 second. Air bubbles are released from the blowhole and rise to the surface of the water. If a squeak is emitted in the air, you can see how the blowhole valve makes a barely noticeable movement with its edges. From sounds with a frequency of up to 12,000 hertz, creaks heard during feeding and similar to meowing, as well as frequent crackling sounds with a cycle shorter than 0, are recorded on magnetic film (except for whistling). ,2-0.4 seconds, no longer perceptible to the human ear and intended for echolocation. Sound is supplied using air sacs and a system of sinuses in which resonating frequencies are excited.

Reproduction. Males predominate in catches and among embryos (about 53%). The height of mating and puppies occurs in the summer months, but the breeding season is spread over six months (from May to November). In the Black Sea it was seen in summer time departure of females from the shores in front of the pup. Childbirth takes place under water (regardless of the weather) and only very rarely can you see the tail of a newborn baby in the female’s vulva when it emerges. The newborn immediately swims well. The placenta lingers in the female’s birth canal for up to 1.5–2 hours.

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

Females, like bottlenose dolphins, probably protect the calf in the first weeks of its life, and therefore separate from other relatives, moving away from the shores. This is confirmed by observations of the differentiation of dolphin schools by sex and age. In winter there are two types of schools - of adult males and of adult females with young animals, and in summer there are six types: pre-pregnant (pregnant females); children's (nursing sleds with babies); nuptial (sexually mature individuals of both sexes with a small part of sucklings that are almost finished dairy nutrition); immature; remnants (in spring and early summer) of winter schools of males that have not yet broken up; 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 feeding the calf, with which the connection with which is sharply weakened. Mating is accompanied by fights between males, as evidenced by bite marks, common on the body of adult males, but rare on the skin of females. Only males bite, and most intensely during sexual activity.

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

Dark V-shaped "cape" with a depression under the dorsal fin
- the pattern on the sides resembles hourglass
- white belly and lower 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 worn out. The greatest condylobasal length of the skull is 485 mm (in the Black Sea 421 mm).

Fishing. We catch dolphins with purse seines in the Black Sea; products are processed at fish factories in Novorossiysk and Tuapse. Anapa and other cities.
Average weight bobwhite 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, muscles of the back and tail 6350, spine 2550, ribs with intercostal muscles 1850, fat pad 520, dorsal fin 250, pectoral fins 475, tail 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
The cod oil substitute “delphinol” is produced from lard; fat is used in the paint and varnish industry, as well as for lubricating precision mechanisms, producing technical machine oil, etc.

Literature:
1. “The Life of Animals”, in volume 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. Cetacean fauna of the seas of the USSR, 1961

White-sided dolphin, aka - common dolphin- a mammal from the order Cetacea, the suborder of toothed whales and the dolphin family.

Appearance of a common dolphin

The body length of an adult common dolphin ranges from 160 to 260 cm, and its body weight is 60 to 80 kg. Females of this species of dolphins have a shorter body than males by an average of 5–10 cm.

The common dolphin has a slender build. The relatively long beak is limited by grooves from the fat pad.

The length of the rostrum in the skull is 1.5–2 times the length of the braincase. On the palatal side of the rostrum there are two deep grooves running in the longitudinal direction.

From below and from the sides the dolphin is colored white. On the sides there is a complex pattern consisting of 1–3 gray lateral stripes directed from the genitals to the front of the body, as well as two elongated gray fields. Near the anterior edge of the fat pad, a dark stripe runs from eye to eye along the bridge of the nose. Also, a dark stripe extends to the chin from the base of the pectoral fins.

Habitat of the common dolphin

This species of dolphin is distributed from the latitudes of Iceland, northern Norway, the southern part of the Kuril ridge, Newfoundland and Washington state to the southern latitudes of Tasmania, South Africa, the island of Tristan da Cunha, and New Zealand.

This species is very numerous in the temperate waters of the northern hemisphere (Black and Mediterranean Sea, coast of Brittany, Gulf of Gascony, waters of Japan, Nova Scotia, California, New Zealand and Australia. Common dolphin is present in smaller numbers in tropical waters. Here it is found from the shores of Sierra Leone, Rio de Janeiro, the Bahamas, Jamaica, India and the Gulf of Mexico.

In the northern hemisphere, the common dolphin is found at higher latitudes compared to the southern hemisphere. This species is rare in the Norwegian Sea; rarely penetrates into the Baltic Sea; not found in the Barents Sea. The Black Sea population of common dolphins appeared earlier than the porpoises and bottlenose dolphins living here. She is well isolated. Black Sea individuals do not migrate to the Mediterranean Sea.

Dry out the voice of the common dolphin

Lifestyle of the common dolphin

The white-sided dolphin can reach speeds of up to 55 km/h. Disturbed herd of dolphins on high speed rushes in one direction, jumping over the water. The length of each such jump is equal to 2–3 times the length of the dolphin’s body. In the process of such movements, the distance that the dolphin covers in the air is much greater than that which it swims underwater. The speed of normal herd transitions is somewhat lower, and is approximately 2 m/s.

Common dolphins live in families consisting of several generations, which were born by the same female. Pregnant females, as well as lactating females with young animals and males, sometimes form separate groups. During the breeding season, special mating groups are created, consisting of sexually mature females and males. Sometimes, usually during feeding, single individuals of this species join herds of other dolphin species.

Common dolphins are excellent at navigating in the water. They are helped in this by their sense organs, called the echolocation apparatus. Dolphins also have excellent hearing. Vision, in turn, is quite weak.

Diet of the common dolphin

Like other dolphin species, the common dolphin's diet is dominated by fish. The menu also includes a small amount cephalopods and crustaceans.

In the diet of individuals living in the Black Sea, the first place is occupied by sprats and anchovy. In second place are red mullet, haddock, pelagic pipefish, and sea cockroach Idotea. On last place There are bonito, mackerel, mullet, blennies, herring and greenfinches. Very rarely, a dolphin eats shrimp and shellfish.

The menu of individuals living outside the Black Sea consists of saury, mackerel, capelin, anchovies, herring, sardines, mackerel, stingray, mullet, squid and flying fish.

Reproduction of common dolphins

Judging by the sex of the embryos found inside the caught dolphins, females make up 47%, and males, respectively, 53% of the offspring. The breeding season of common dolphins extends over 6 months, and lasts from May to November. Peak mating occurs in the summer season. The birth, called a pup, takes place underwater. IN mating season fights between males are apparently not uncommon. This is evidenced by numerous bites on the body of males, and the absence of such on the body of females.

The female begins to reproduce in the second or third year of life. Pregnancy lasts 10–11 months. Newborn females have a body length of 80–85 cm, and males 85–95 cm. Almost immediately after their birth, the cubs already know how to swim well and feel free in the water column. Like bottlenose dolphins, female common dolphins care for their offspring during the first few weeks of life. During this period, females along with their cubs, having separated from the rest of the individuals, swim far into the open sea. Breastfeeding lasts 4–6 months.

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Dolphins are not fish at all, as many believe, but small aquatic mammals belonging to the order Cetaceans. Dolphins are directly related to whales and killer whales (the latter are actually large dolphins). Very distant relatives of dolphins can be considered pinnipeds and land predators leading water image life (of sea otters). This group of animals is vast and diverse and includes 50 species.

Bottlenose dolphin (Tursiops truncatus).

The common features of all types of dolphins are a naked, streamlined body, flexible and muscular at the same time, highly modified limbs that have turned into fins, a small head with a pointed snout and a dorsal fin, which most dolphins have. On the head of these animals the transition between the frontal part and the nose is well defined. Dolphins have small eyes and do not see well because they do not use their eyesight to track prey. They also lack tactile whiskers and a sense of smell. In our understanding, dolphins do not have a nose as such. The fact is that dolphins are so adapted to constantly living in water that their nostrils have merged into one breathing hole (blowhole), which is located on... the parietal part of the head. This allows animals to breathe when their body is almost completely submerged in water. In addition to the nose, dolphins also lack ears. But they have a rumor, it just works in an unusual way. In the absence of external auditory openings, the perception of sounds was taken over by the inner ear and air cushions in the frontal part of the brain, which act as a resonator. These animals have perfect echolocation! They pick up the reflected sound wave and thus determine the location of the object. By the nature of sound vibrations, dolphins also determine the distance to an object and its nature (density, structure, material from which it is made). Without exaggeration, we can say that dolphins literally see the world around us through sounds and see it much better than other creatures! The dolphins themselves make sounds similar to crackling, clicking, clicking and even chirping. The sounds made by dolphins are extremely diverse and complex; they consist of many individual modulations and are used by animals not only for communication, but also for communication with the outside world. Dolphins have numerous teeth (40-60 pieces), small and uniform. This structure of the dental system is due to the fact that dolphins only catch prey, but do not chew it. The body of dolphins is completely naked, devoid of even the slightest rudiments of hair. Moreover, the skin of these animals has special structure, reducing water friction and improving the hydrodynamic properties of the body.

Common dolphin or common dolphin (Delphinus delphis).

Since dolphins are very mobile and constantly move in the water high speeds, the outer layer of skin is constantly worn out. Therefore, the deep layers of the skin have a powerful supply of regenerating cells that are constantly dividing. A dolphin goes through 25 layers of skin cells per day! We can say that these animals are in a state of continuous molting. Dolphins have two types of coloring: plain (gray, black, pink) and contrasting, when large areas of the body are painted black and white.

Commerson's dolphin (Cephalorhynchus commersonii) has a bright black and white coloration.

Dolphins live exclusively in water bodies, never leaving the water column. The range of these animals is very extensive and covers almost the entire globe. There are no dolphins only in the coldest Arctic and sub-Antarctic waters. Basically, these mammals live in salty waters - seas and oceans, but some species of dolphins (Chinese and Amazonian river dolphins) live in large rivers. Dolphins prefer open spaces, moving freely across the ocean, but sometimes they come close to the shore and even play in the surf. Another phenomenon associated with this is the so-called stranding of dolphins. Cases of individual animals and even entire schools of dolphins being found on the shore have long been known. Discarded animals are always healthy and often still alive. For what reason they end up on the shore, scientists are still arguing. It is impossible to blame dolphins for errors in movement, because their echolocating abilities are highly developed. The idea that dolphins do this on purpose is untenable, since not a single animal is capable of suicide. It is most likely that dolphins end up on the shore due to information “noise” - large quantity sounds made by ship engines, radio frequency beacons, etc. The dolphins' sophisticated echo sounder picks up this cacophony, but their brains are not able to filter out so many sound sources, as a result, the animals see an erroneous "map of the area" and become stranded. This confirms that dolphins die more often in areas of busy shipping and generally close to human civilization.

A school of common dolphins.

All types of dolphins are school animals; their groups can number from 10 to 150 individuals. Their social relationships are very developed. These are friendly animals that maintain peaceful relations with each other; there are no fights or fierce competition between them. But the pack has its own leaders, more experienced animals and young animals. They communicate with each other using sounds of different tones and durations; each member of the herd has their own individual voice. With various signals, dolphins inform each other about impending danger, the availability of food, or the desire to play. Moreover, dolphins indicate each category of objects with their own sound. For example, when a killer whale approaches ( dangerous predator) dolphins “speak” differently than when a whale approaches (just a neighbor), they can combine simple sounds into difficult words and even suggestions. This is nothing more than a speech! That is why dolphins are considered one of the most highly developed animals, putting their intelligence on the same level as apes.

A flock of bottlenose dolphins looks at the underwater photographer with interest.

There is another little-known side to the dolphin mind. Due to high level development, these animals have a lot of free time, not busy searching for food. Dolphins use it for communication, games and... sex. These animals engage in sexual intercourse regardless of the breeding season and the biological cycle of each member of the herd. Thus, sexual relations serve not only for procreation, but also for pleasure. Dolphins also love to play “outdoor games,” as we would call them. They practice jumping out of the water forward, upward, or twisting around their axis like a corkscrew.

By moving its strong tail, a dolphin is able to lift its body above the water, hold it for several seconds, and even move backwards (tail stand).

Dolphins have one more thing in common with humans little known fact. It turns out that despite differences in physiology, dolphins can suffer from diseases that are quite human; in captivity, cases of liver cirrhosis, pneumonia and brain cancer have been recorded.

Dolphins feed exclusively on fish. They prefer small and medium-sized fish - anchovies, sardines. The fishing technique of dolphins is unique. First, the herd scans the water column using echolocation; when a school of fish is detected, the dolphins quickly approach it. Along the way, they make sounds of a special frequency that cause panic in the fish. A school of fish gathers together in a dense heap, and that’s all the dolphins need. As they approach, they work together to catch fish, often while the dolphins exhale air, the bubbles of which create a kind of barrier around the school of fish. Thus, these hunters can catch a significant part of the school of fish. Dolphins also have meal companions: seagulls and gannets monitor the behavior of dolphins from above and, while feeding, attack schools of fish from the air.

A common dolphin fishes with a shark (in the background). In this case, the shark does not pose a threat to the dolphin.

Dolphins are breeding all year round. They have no special mating rituals, but usually the leading male of the herd mates with the female. Mating occurs while moving, and the birth of a baby dolphin occurs while moving. Dolphin calves, like all cetaceans, are born tail first. This is due to the fact that the newborn is under water and for the first breath he must first rise to the surface. Dolphin calves are born so well developed that from the very first seconds of life they swim independently after their mother. However, the mother and members of the herd nearby help the baby rise to the surface, pushing it with their noses. The cub often suckles its mother, thanks to nutritious milk it is growing quickly. Communicating with its relatives, the cub learns from them the art of hunting and soon begins to participate in the life of the herd on an equal basis with adults.

The main enemies of dolphins are sharks and... their own relatives. One of the largest species of dolphins, the killer whale, hunts for warm-blooded inhabitants of the seas. Smaller species often become its prey. Since ancient times, humans have also hunted dolphins. True, dolphin hunting has never been carried out in industrial scale, because besides meat (not the best taste qualities) you can't extract anything from a dolphin carcass. Therefore, only local residents caught dolphins northern countries or sailors on long voyages. Despite this, these animals are still caught in some countries. Such a hunt looks cruel, because the meat of caught dolphins is only used as food for dogs and does not bring any economic benefit. Such actions are doubly absurd considering that many species of dolphins are endangered. These animals die in fishing nets, due to oil spills, and from wounds caused by ship propellers. At the same time, dolphins are often kept in water parks, where they undergo complex training programs and perform in entertainment shows.

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

Area

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

Features of morphology

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

Features of biology

Found in all Black Sea waters of Crimea and in Kerch Strait. Forms large accumulations in the open sea. It feeds on small schooling fish (anchovy, sprat, horse mackerel). The probable age of sexual maturity is 5–10 years, the rate of reproduction in the Black Sea is unknown.

Threats

Deterioration of the food supply due to the invasion of the ctenophore Mnemiopsis leidyi and non-compliance by fishermen with fish production standards; epizootics of various origins.

Security measures

Included in Annex II of the Berne Convention, Annex II of the Bonn Convention, Annex I of the ACCOBAMS Agreement and Annex II International Convention CITES.