Spotted dolphin. Spotted dolphin. Dolphin family - Delphinidae

Variegated dolphins
Scientific classification
International scientific name
Cephalorhynchus (Gray, )
Kinds

Variegated dolphins(lat. Cephalorhynchus) - a genus of sea dolphins. Includes 4 types. They live in the southern hemisphere.

The generic name comes from the Greek. κεφαλή - “head” and Greek. ρυγχος - “mouth, snout.”

Body 110-180 cm long, pectoral fin 15-30 cm long, dorsal fin 7-15 cm high, tail 21-41 cm. Females are slightly larger than males. Weight 26-86 kg. The color is highly contrasting black and white. Chin, sides, the belly and front of the back are white, the rest is black. Sometimes the back is completely black. The nose is dull. There are 24-35 teeth on each side of each jaw.

Typically playful. They live in flocks of 2-8 individuals in shallow waters. They feed mainly on bottom invertebrates, as well as fish.

The cubs begin to eat solid food at the age of 6 months and remain with their mother for 2 years; Puberty occurs at 6-9 years. Maximum observed lifespan is 20 years.

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Literature

An excerpt characterizing the Motley Dolphins

In the middle of the road, Nikolai let the coachman hold the horses, ran up to Natasha’s sleigh for a moment and stood on the lead.
“Natasha,” he told her in a whisper in French, “you know, I’ve made up my mind about Sonya.”
-Did you tell her? – Natasha asked, suddenly beaming with joy.
- Oh, how strange you are with those mustaches and eyebrows, Natasha! Are you glad?
– I’m so glad, so glad! I was already angry with you. I didn't tell you, but you treated her badly. This is such a heart, Nicolas. I am so glad! “I can be nasty, but I was ashamed to be the only happy one without Sonya,” Natasha continued. “Now I’m so glad, well, run to her.”
- No, wait, oh, how funny you are! - said Nikolai, still peering at her, and in his sister, too, finding something new, extraordinary and charmingly tender, which he had never seen in her before. - Natasha, something magical. A?
“Yes,” she answered, “you did great.”
“If I had seen her before as she is now,” thought Nikolai, “I would have asked long ago what to do and would have done whatever she ordered, and everything would have been fine.”
“So you’re happy, and I did good?”
- Oh, so good! I recently quarreled with my mother over this. Mom said she's catching you. How can you say this? I almost got into a fight with my mom. And I will never allow anyone to say or think anything bad about her, because there is only good in her.

Scientific classification

intermediate ranks

Domain: Eukaryotes

Kingdom: Animals

Type: Chordata

Class: Mammals

Order: Cetaceans

Family: Dolphinidae

International scientific name

Pied dolphins (Cephalorhynchus)

Common dolphins (Delphinus)

Pygmy killer whales (Feresa)

Pilot whales (Globicephala)

Gray dolphins (Grampus)

Malaysian dolphins (Lagenodelphis)

Short-headed dolphins (Lagenorhynchus)

Whale dolphins (Lissodelphis)

Irrawaddy dolphins (Orcaella)

Killer whales (Orcinus)

Beakless dolphins (Peponocephala)

Lesser killer whales (Pseudorca)

Long-beaked dolphins (Sotalia)

Humpback dolphins (Sousa)

Dolphins (Stenella)

Large-toothed dolphins (Steno)

Bottlenose dolphins (Tursiops)

Dolphins, or dolphins (lat. Delphinidae) are a family of mammals of the order Cetaceans, suborder of toothed whales (Odontoceti).

general description

Skeleton (bottom) and model (top) of a dolphin

Dolphins are characterized by the presence in both jaws of a fairly significant number of uniform 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, and there is a dorsal fin.

Very agile and dexterous voracious predators, living mainly socially, are found in all seas, even rise high into rivers, feeding mainly on fish, mollusks, and crustaceans; sometimes they attack their relatives. They are also distinguished by their curiosity and traditional good attitude to a person.

Some dolphins have a mouth extended forward in the form of a beak; in others the head is rounded in front, without a beak-like mouth.

Dolphins swim extremely fast, schools of dolphins often follow ships, using, in addition to the “Grey's paradox” described below, the wake of ships for even greater acceleration. The dolphin has been loved and popular since ancient times: there are many poetic legends and beliefs (the legend of Arion) about dolphins and their sculptural images.

The word dolphin goes back to the Greek δελφίς (delphis), which in turn came from the Indo-European root *gʷelbh - “womb”, “womb”, “womb”. The name of the animal can be interpreted as "newborn baby" (possibly due to external resemblance with a baby or because the cry of a dolphin is similar to the cry of a child).

Physiology

The gestation period of dolphins is 10-18 months. The female dolphin usually brings one calf 50-60 cm long and carefully guards it for some time. Dolphins apparently grow slowly, and their life expectancy should be quite significant (20-30 years). In some cases, scientists have observed that the cubs do not sleep at all for the first month of life, forcing the females to be active during this entire time. In the 1970s, a group of scientists from the Utrish sea station IPEE discovered an unusual sleep pattern in dolphins. Unlike other mammals studied at that time, only one of the two hemispheres of the brain is alternately in a state of slow-wave sleep. Perhaps, main reason This is because dolphins are forced from time to time to rise to the surface of the water to breathe.

Brain Development

Dolphins' brains are much larger in relation to their body size than those of our closest relatives, chimpanzees, and their behavior indicates a high degree of mental development. The brain of an adult dolphin weighs about 1,700 grams, while that of a human is 1,400. A dolphin has twice as many convolutions in the cerebral cortex as a human.

According to the latest scientific data from cognitive ethology and zoopsychology, dolphins not only have a “vocabulary” of up to 14,000 sound signals, which allows them to communicate with each other, but also have self-awareness, “social cognition” and emotional empathy, a willingness to help newborns and the sick , pushing them to the surface of the water.

Movement

Associated with dolphins is the so-called. "Gray's Paradox". In the 1930s Englishman James Gray was surprised by the unusually high swimming speed of dolphins (37 km/h according to his measurements). Having made the necessary calculations, Gray showed that according to the laws of hydrodynamics for bodies with constant surface properties, dolphins should have had several times greater muscle strength than was observed in them.

Accordingly, he suggested that dolphins are able to control the streamlining of their bodies, maintaining a laminar flow around them at speeds for which it should already become turbulent. In the USA and Great Britain after World War II and 10 years later in the USSR, attempts began to prove or disprove this assumption. In the USA, they practically stopped in the period from 1965-1966 to 1983, since, based on incorrect estimates, erroneous conclusions were made that the “Gray's paradox” does not exist, and dolphins only need muscular energy to develop such speed. In the USSR, attempts continued in 1971-1973. The first experimental confirmation of Gray's guess appeared.

Signals

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

Since 1942, researchers have learned that dolphins and toothed whales emit ultrasonic echolocation clicks, which they use to navigate muddy water. Working with the Hawaiian spinner dolphin (Stenella longirostris), whale researcher Professor Ken Norris found that by directing ultrasonic signals at schools of fish, whales can stun and sometimes even kill fish. These signals cause the fish's air-filled swim bladders to resonate so intensely that the vibration transmitted to body tissue disorients the fish. No less interesting was the discovery that dolphins can use not only very high, but also low-frequency sounds to stun prey. In 2000, Dr Vincent Janik studied the common bottlenose dolphin (Tursiops truncatus) in the Moray Firth, Elginshire. He found that bottlenose dolphins produce a characteristic sharp noise of low-frequency sounds exclusively when eating. Since dolphins themselves are insensitive to low frequencies, Zhanik suggests that dolphins produce these sound signals to stun their prey.

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

Scientists have already counted 186 different “whistles” in the “speech” of dolphins. They have approximately the same levels of organization of sounds as a person: six, that is, sound, syllable, word, phrase, paragraph, context, they have their own dialects.

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

Currently, a number of scientists are working on deciphering complex signals using the CymaScope device, designed for this purpose by the British acoustic engineer John Stuart Reid.

Dolphins are used in pet therapy to treat people using ultrasound sonar.

Representatives

Common dolphin

The common dolphin (Delphinus delphis L.) has from 100 to 200 (their number varies) small, conical, slightly curved teeth, separated by equal intervals; the snout is of moderate length separated by a groove from the slightly convex forehead. The upper side of the body and fins are grayish or greenish-black; the belly is white; the skin is very smooth and shiny. Reaches 2 m in length; dorsal fin height 80 cm; pectoral fins 15-18 cm wide, 55-60 cm long. It is found in all seas of the northern hemisphere, both off the coast and in the open sea; also enters rivers. They live in flocks of 10, 100 or more (up to several thousand) animals.

D This species of dolphins is quite common and often seen. Typically, representatives of the genus form flocks and move together. They can be seen near the shore, or accompanying ships. The size of an adult individual is about 2 m, weight is about 80 kg.

The common dolphin prefers fish as food, but if necessary, it can also feed on other marine life. When choosing fish, he will give preference to anchovy, but will not disdain octopus in difficult times.

The animal is very mobile, it can jump, as if flying out of the water, and such a flight is carried out at a distance of about 10 m. It is often on the surface, and spends less time under water in total. But there is also deep-sea representatives, which hunt and live at depth, occasionally rising to the upper layers of water.

Dolphins of this species usually live in births - for example, cohabitation of several generations is often found. During the mating season, it is possible to divide into flocks based on gender. Females “in position” or young mothers may separate. Animals help each other - no matter how strange it sounds, and this makes them even more like people.

Average term The lifespan of dolphins is 30-35 years - this species is no different from the others. The speech of the common dolphin is varied, there are loud and strong sounds, usually the animals “whistle.” These individuals can be found in the oceans and seas almost everywhere - the population is very widespread. Animal reproduction occurs in warm months, the baby is carried for about a year.

Appearance- body size about 2 m, elongated muzzle and dark color. A distinctive feature is the light sides and belly. The eyes and fins are highlighted. The back is dark, in the form of a “blanket”. The oral cavity contains sharp teeth, of which dolphins have about 200.

bottlenose dolphins

Bottlenose dolphins (Tursiops truncatus) are the most famous and popular species of dolphin. When you mention a dolphin, a person is more likely to imagine this particular species. Bottlenose dolphins owe their popularity partly to numerous references in cinema and fiction and high learning ability.

Distributed throughout the world. Representatives of the genus of bottlenose dolphins living in the northern part Atlantic Ocean(occasionally enter the Baltic Sea), are less common than the previous species and reach a larger size (3.5-4.5 m in length); the Greenlanders called them “nezarnak”.

This type of dolphin is exactly the one that is well known to all of us from films, videos, etc., and each of us, probably, could see it when we were at sea. The population is very common, usually in groups of 5-10 animals. Flocks of more than 400 animals are possible - but this can only be seen at sea.

Adults measure more than 2 m in size and weigh approximately 200-300 kg. They usually choose fish as food, sometimes octopuses are used. This type of dolphin has been well studied by scientists. The animal can live either alone or in groups. It is often located near the shore, but searches for food at the bottom. The bottlenose dolphin is active during the daytime, and at night it sleeps. To sleep, the dolphin is placed on the surface of the water; it can also rest during the day, after a hearty lunch.

The animal's speech has been well studied - today certain signals can be identified, for example, when a bottlenose dolphin wants to eat, it makes sounds similar to the meowing of a cat. If she is hunting, the sound is similar to the barking of a dog; to scare away the animal cracks or clicks. There are other sounds that allow animals to communicate quite freely.

The animal can be found in almost all ocean waters, preferring warmer ones. The bottlenose dolphin breeds in the warm season and bears its young for 1 year. A pregnant female avoids other dolphins and becomes less active. The baby appears underwater and immediately rises to the surface. The female finishes feeding after about 2 years.

The appearance of a dolphin is familiar to everyone - a dark color with a light belly, a large dorsal fin, an elongated muzzle, and clear outlines. Variations in color are possible, but small. The animal has a friendly character, is highly trainable, and quickly remembers commands.

Classification

Suborder Toothed whales(Odontoceti)

1.Family River dolphins (Platanistidae)

• Gangetic dolphin or susuk (Platanista gangetica)
• Indian dolphin (Platanista indi)
• Amazonian Inia or buto (Inia geoffresis)
• Bolivian river dolphin(Inia boliviensis)
• Chinese lake dolphin (Lipotes vexillifer)
• La Plata dolphin (Pontoporia blainvillei)

2.Dolphin family (Delphinidae)

Genus Bottlenose dolphin (Tursiops)

• Bottlenose dolphin (T. truncatus)

Genus Common dolphins (Delphinus)

• Common dolphin (D. delphis)
• Tropical dolphin (D. tropicalis)

Genus Prodolphins (Stenella)

• Striped dolphin (S. caeruleoalbus)
• Malayan dolphin (S. dubia)
• Spotted dolphin (S. pernettyi)
• Bridle dolphin (S. frontalis)
• Spinning dolphin (S. longirostris)

Genus Long-beaked dolphins (Sotalia)

• Amazonian dolphin(S. fluviatilis)
• Chinese white dolphin(S. chinensis)
• Sunda white dolphin (S. borneensis)
• West African dolphin (S. teuszi)
• Guiana dolphin (S. guianensis)
• Lead dolphin (S. plumbea)
• Speckled dolphin (S. lentiginosus)

Genus Large-toothed dolphins (Steno)

• Wrinkled-toothed dolphin (S. bredanensis)

Genus Cetacean dolphins (Lissodelphis)

• Northern right whale dolphin (L. borealis)
• Southern right whale dolphin (L. peroni)

Genus Short-headed dolphins (Lagenorhynchus)

• White-sided dolphin (L. acutus)
• White-faced dolphin (L. albirostris)
• Crossed dolphin (L. criciger)
• Short-headed dolphin (L. obliquidens)
• Dusky dolphin (L. obscurus)
• Southern dolphin (L.australis)

Genus Beakless dolphins (Peponocephala)

• Beakless dolphin (P. electra)

Genus Malaysian dolphins (Lagenodelphis)

• Commerson's dolphin (C. commersoni)
• Heaviside's dolphin (C. heavisidei)
• Hector's dolphin (C. hectori)
• Chilean dolphin (C. eutropia)

In total, the dolphin family includes about 40 species. Of these, 11 species are found in Russian waters. Porpoises are often classified as dolphins.

Dolphins are also called species belonging to the superfamily river dolphins.

Security

Some species and subspecies of dolphins are on the verge of extinction and are protected by local and international legislation. One example is the New Zealand subspecies of Hector's dolphin known as the Maui dolphin (Cephalorhynchus hectori maui). In total, fewer than 150 of these dolphins live in the waters of New Zealand's North Island.

Since 1966, after the adoption of the CITES Convention (Appendix 2), dolphin fishing was prohibited in the USSR. Türkiye has not yet ratified this treaty.

2007 was declared by the UN as the “Year of the Dolphin” and, due to its success, was extended to 2008.

Dolphin therapy

Dolphin therapy is a method of psychotherapy that is based on communication between a person and a dolphin. It is carried out in the form of communication, games and simple joint exercises under the supervision of a specialist. Often used in the treatment of diseases such as childhood cerebral paralysis, early childhood autism, attention deficit hyperactivity disorder, etc.

Fighting dolphins

Fighting dolphins are dolphins trained for military purposes. United States and Russian security agencies have trained oceanic dolphins for several tasks.

Their training included detecting underwater mines, rescuing sailors after their ship was destroyed, locating enemy combatants, and searching for and destroying submarines using kamikaze techniques.

There were even suggestions about the possibility of installing complex equipment, for example, sonar jamming devices, search devices, and so on. The U.S. Navy denies ever training marine mammals to cause damage or harm to humans or to deliver weapons to destroy enemy ships.

Captivity

A dolphinarium is a special aquarium for demonstrating trained dolphins to spectators. As a rule, large aquariums show killer whales and bottlenose dolphins, as well as performances with their participation.

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

People and dolphins

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

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

The dolphin is smart, kind, beautiful, he is an excellent learner, analyzes and remembers.

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

The most popular bottlenose dolphin ( big dolphin), which is what people generally mean when talking about encounters with representatives of this species. They are well studied and tamed. Bottlenose dolphins are featured in films and participate in programs for the rehabilitation of children suffering from various neurological ailments.

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

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

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

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

How do dolphins breathe?

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

Do dolphins have ears?

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

How do dolphins sleep?

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

Where do dolphins live?

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

Dolphin language

Dolphins are animals social, they live in packs, which can number from 10 to 100 (sometimes more) individuals, fighting off enemies with common efforts. Within the pack there is practically no competition or fights between them; fellow tribesmen coexist peacefully with each other. Dolphins communicate using sounds and signals. Dolphin language extraordinarily varied. The “conversation” of these mammals includes clicking, whistling, barking, and chirping. The spectrum of dolphin voices extends from the most low frequencies before ultrasound. Moreover, they can put simple sounds into words and sentences, passing information to each other.

What do dolphins eat?

The diet of dolphins includes exclusively fish, with preference given to anchovies. The hunting method used by the animals is also interesting. A school of dolphins finds a school of fish and uses special sounds to force it into a tight group. As a result of such a hunt most of school becomes prey for dolphins. This feature is often used when attacking frightened fish from the air. There are known facts when dolphins helped fishermen by driving a school of fish into their nets.

Sharks and dolphins

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

Dolphin species

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

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

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

• Common dolphin ( common dolphin) (Delphinus delphis)

The length of the sea animal often reaches 2.4 meters, the weight of the dolphin varies between 60-80 kilograms. In the area of ​​the back, the common dolphin is colored dark blue or almost black, the belly is white, and along the light sides there is a spectacular stripe of a yellowish-gray hue. This species of dolphin lives in the Mediterranean and Black Seas, and feels at ease in the Atlantic and Pacific oceans. Common dolphin found on the east coast South America, along the coasts of New Zealand and South Africa, in the seas of Japan and Korea.

• White-faced dolphin ( Lagenorhynchus albirostris)

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

• Large-toothed dolphin ( Steno bredanensis)

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

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

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

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

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

• Chinese dolphin (Sousa chinensis)

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

• Irrawaddy dolphin ( Orcaella brevirostris)

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

• Cruciform dolphin ( Lagenorhynchus cruciger)

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

• Killer whale (killer whale) ( Orcinus orca)

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

Commerson's dolphin is also known to the world of ichthyologists as the piebald dolphin, due to its unusual color. This mammal belongs to the genus of spotted dolphins.

This breed got its name thanks to the researcher Phillibert Commerson, who first described and classified this species back in 1767.

Appearance of a spotted dolphin

Externally, Commerson's dolphins are very difficult to confuse with other breeds due to their specific body shape. Their head seems to be tilted forward, relative to the rest of the body. The color of these mammals is also characteristic, which accurately identifies them.

The head of the piebald dolphin is black; the back from the upper fin to the tail, and the tail itself, are also dark in color. More dark markings are located on the throat and on the front lower fins. The rest of the body of this animal is white, which makes it clearly visible in the sea waves. It is worth noting that the boundary between the two colors is very clear, which is what gave the breed its second name – motley dolphin. Their dorsal fin is quite long, with a curved tip, but the rear fins are concave, but cannot be called sickle-shaped.

Commerson's dolphins are one of the smallest cetacean breeds, their body length rarely exceeding 1.7 m, and the weight of an adult individual is about 35 - 60 kg.

Commerson's dolphin has a distinctive body shape, it has a black head, white throat and body, and a dorsal fin.

Females differ from males very simply: males have black spot in the shape of a tear, but in females this spot is round and has no sharp corners. Individuals of both sexes have 28-30 incisors in each row of teeth.

Habitat of Commerson's dolphin

In nature, Commerson's dolphins are found in only two places. The first habitat is the southern end of the continent of South America, or more precisely, along the entire coast of modern Patagonia, in the waters surrounding Cape Horn, as well as east of the central Strait of Magellan. There are also many of them in the waters of the Falkland Islands. Another population of piebald dolphins lives at a distance of 8,500 km from South America - in Indian Ocean, near the Kerguelen Island. In other places, this type of dolphin in wildlife was not observed.

Pied dolphins are very active mammals, they like to swim quickly on the surface and jump out of the water.

Lifestyle and diet of motley dolphins

Commerson's dolphins can easily be called curious and active animals. It has been noted many times that these mammals happily accompany ships, diving and jumping out of the water right next to the side. The characteristic swimming style of these animals is called the “up-down” style, when an individual sharply changes its swimming depth. This technique helps them hunt and track prey. Typically, piebald dolphins live in groups of 3-7 individuals, but you can often find 12-15 animals in one pod.

As for food, piebald dolphins are not very different from their counterparts of other species - they eat fish with pleasure different types, as well as cephalopods like cuttlefish and squid.

It is also known that a significant part of the diet of South American dolphins consists of various crustaceans, which they eat with great pleasure. In addition, the diet of these animals often contains greens, in particular green algae, which they eat to obtain the necessary vitamins and microelements.

Reproduction of Commerson's dolphins

Unfortunately, the reproduction process of Commerson's dolphin has not been studied in the smallest detail - only the basic facts are known. The maximum breeding age is from 6 to 9 years. The onset of puberty is 1-1.5 years. Mating games Pied dolphin sightings usually take place in the spring or summer, and last approximately a few weeks. Babies are born after 11 months of pregnancy, while the female carries only 1 cub.

Stenella attenuata (Pantropical Spotted Dolphin)

Order Cetaceans - Cetacea

Suborder Toothed whales (Odontoceti)

Dolphin family - Delphinidae

Genus Prodolphins (Stenella)

Two subspecies of the genus are officially recognized Stenella, differing in habitat: Stenella attenuata And Stenella graffmani.

general information

• Species status- common.
• Habitat- tropical seas and oceans.
• Number of groups- 100-1000.
• The location of the dorsal fin is in the center.
• The length of a newborn is 0.80-0.85 m.
• The length of an adult is 1.66-2.57 m.
• Adult weight is 60-119 kg, males are larger than females.
• The weight of a newborn is about 11.
• Life expectancy is more than 20 years.
• Food: small fish, squid and octopus.

Area

Pantropical Spotted Dolphin widespread species (second only to ), found in all oceans from 40" N to 40" S. The distribution range also extends to some closed seas: the Red Sea and the Persian Gulf. Not observed in the Mediterranean Sea.

Stenella graffmani found only in a narrow strip (less than 200 km wide) along the coast Latin America, from southern Mexico to northern Peru.

Number and status

In the eastern Pacific Ocean, there were various estimates of 228,038 pantropical dolphins (2000). There are approximately 737,000 animals in the northeast (2003), a 76% decrease from the 1959 population. There are no signs of recovery, despite a sharp decline in dolphin mortality in recent years (2005):

• Eastern Pacific - 228,038
• Northeast Pacific - 737,000
• Western South Pacific - 876,075
• Hawaiian waters - 8,978
• Japanese waters - 438,000
• north Gulf of Mexico - 34 067
• East Coast of the United States - 4,439
• East Sulu Sea - 14,930
• strait between the islands of Negros and Cebu - 640

Status in the International Red Book ( L.C.) - least threat.

Appearance

Most distinctive feature Pantropical Spotted Dolphin are spots that are absent in newborn calves. Dark spots appear on the bottom as they grow older. In adults, the abdominal spots merge and disappear, and the dorsal light spots sometimes intensify to such an extent that the animal's back appears completely white. The intensity and location of coloration varies by region.

The dorsal fin is narrow, sickle-shaped. The long, thin beak is separated from the head by folds. Most adults have a white beak tip. The blowhole is located on the top of the head.

The pantropical dolphin has a very thin layer subcutaneous fat, which is why the energy reserve is very small. He is forced to compensate for this deficiency by taking high-calorie foods with a high protein content.

Males, 1.5-2.6 meters long, are slightly larger than females (1.7-2.5 m), weighing up to 119 kg.

• newborns without spots
• narrow, sickle-shaped dorsal fin
• long thin beak with white tip
• slender body
• males are larger than females
• thin layer of subcutaneous fat
• excellent swimmer
• acrobat

Subspecies Stenella graffmani It is distinguished by a larger stocky body, a thick beak and more extensive spots.

Lifestyle and nutrition

Pantropical Spotted Dolphin most often found at depths less than 50 m and with surface water temperatures greater than 25 degrees Celsius. These conditions are met all year round in the region north of the equator in the eastern Pacific Ocean.

Schools of pantropical dolphins, ranging from 100 to 1000 individuals, often coexist with schools of tuna. This may be due to the same diet, as well as increased levels of protection from predators.

An excellent swimmer and acrobat. Juveniles impress with their high vertical leaps from the water. The 2.5 meter male jumps about 7 meters into the air, which is equivalent to a two-story building.

Stenella attenuata They feed mainly at night on small fish, squid and crustaceans, which rise almost to the surface at dusk. The diet of coastal forms is believed to consist mainly of large bottom-dwelling fish.

Cubs

Once every two to three years, the female gives birth to 1 cub, 0.8-0.85 cm long, without spots. The duration of pregnancy is about 11-11.5 months. The lactation period is from 1 to 2 years. Lactating females consume significantly more fish than adult or pregnant females. More protein, and accordingly more energy reserves, is obtained by eating fish, rather than squid of the same weight. Fish contains more calcium and phosphorus, which promote lactation.

Pantropical dolphins begin to eat solid food (squid) at about 6 months of age (with a height of 115 cm), but continue to suckle until they are two years old.

Females become sexually mature at 9-11 years, males at the age of 12 to 15 years.

Pantropical dolphin and man

A sharp decrease in the population (by 76%) was due to the fact that fishermen, in order to catch tuna more efficiently, deliberately captured dolphins along with tuna, with the expectation of then releasing the dolphins from the nets. But many dolphins died in the nets or were caught in the nets many times, which led to internal injuries, stress, hyperemia, and separation of calves from females. Since 1960, several million dolphins have been killed.

In Japan, the Solomon Islands and the Philippines, pantropical dolphins continue to be captured for human consumption. The meat is also used to attract sharks in fishing.

In 1970, the United States developed laws and policies aimed at reducing dolphin bycatch by improving fishing methods. In 1999 International agreement Dolphin Conservation Act came into effect. The main tuna fishing countries in the eastern Pacific have been bound by certain measures, such as having observers on boats and limiting the dolphin mortality limit. Thanks to these measures, there is hope for the restoration of this population. Since 1986, dolphin mortality has decreased by 97%.