Earlier, in other articles, we met with some representatives aquatic mammals. Today we will talk about wonderful animals, which, according to scientists, are almost on the highest step in the development of intelligence after humans. It's about dolphins. Which of you has not seen these lovely creatures while relaxing, for example, on the Black Sea? In this section, we will tell you about the superfamily River dolphins, or as they are also commonly called Freshwater dolphins.

Superfamily River dolphins

These amazing aquatic animals (lat. Platanistidae) belong to the class Mammals, order Cetaceans and suborder Toothed whales. The considered superfamily consists of four existing in modern world families that represent four species of the same name:

Chinese river dolphins (Lipotidae)

As a species, these animals were first discovered in 1918 in freshwater Chinese lake Dongting, about a thousand kilometers from the mouth of the Yangtze River. Their body weight is about 120 kg., And the length is up to 2.30 m. Like most other species of dolphins, Chinese river dolphins have an anti-shade color - a gray back with sides and a light belly. The snout (beak) is very elongated and slightly bent upwards. Vision is poorly developed, as in most other species.

Stay in small groups of 3-5 individuals, sometimes up to ten or twelve. They feed mainly different types bottom fish and mollusks, whose hard shells are crushed with their strong teeth with lateral outgrowths that give the dolphin teeth the shape of an anchor. Getting food for themselves, they dig with their long beak in the mud at the bottom of the reservoir, looking for worms with mollusks and catching lurking eels with catfish. Much of what concerns their behavior and lifestyle currently remains a mystery.

Gangetic dolphins or Susuki (Platanistidae)

Representatives of this species are able to make breath sounds characteristic of the species, which served as the reason for the name of the species. Today, only a small population of these dolphins has survived. This type river dolphins are very different from their counterparts in appearance and reach about 2.5 m in length. Gangetic dolphins have an unusual fan-shaped pectoral fin, with five crests and expressive anti-shadow coloration (dark - gray back and sides, light bottom).

These animals live in freshwater rivers India and Pakistan, different slow flow: Ganges, Indus, Brahmaputra and Hooghly, as well as in the tributaries of these rivers (usually in the upper reaches). Sometimes, during the rainy season, they can descend into the mouths of the rivers, but they never enter the sea. Susuki can stay under water continuously for about two minutes. It is interesting that the eyes of the Gangetic dolphins, or rather the corneas of the eyes, perform not a visual, but a tactile function, since due to the benthic lifestyle, these mammals have lost their eye lenses, and their optic nerves have completely atrophied;

Amazonian dolphins (Iniidae)

These mammals are also called Inii, otherwise Boutos live in large South American rivers: Tocantins, Amazon, Orinoco, as well as in their many extended tributaries of Venezuela, Colombia, Brazil, Peru, Bolivia and Guiana. During periods of flooding of these rivers, Amazonian dolphins can swim freely among the flooded trees and swim, thanks to such floods, from one river basin to another. The body length of these animals can reach up to 2.5 m, and weight up to 130 kg. Sexual dimorphism is well expressed: males are much larger and more massive than females. The color of the inia varies depending on the age and location of their habitat.

Young individuals are painted in a pale grayish color, older ones acquire an anti-shadow, very beautiful color - light blue above, and white or pinkish below. Dolphins that live in rivers are usually lighter than lake ones. Both live either alone or in small groups. Their beak is quite long, decorated with hard bristles and has a slightly curved cylindrical shape. Their long jaws are equipped with two rows of strong teeth, the number of which can range from 104 to 132 units. Despite the fact that the eyes of these mammals are very small, unlike the eyes of other species of river dolphins, they see quite well. Inia lead an equally active lifestyle, both during the day and at night, and feed on crabs and various species. freshwater fish. These dolphins are very sociable and gullible towards people. Unusual and mysterious behavior in recent times carefully studied and analyzed by scientists in different aquariums around the world.

La Plata dolphins (Pontoporiidae)

This is the only family and species, out of the four considered, that can live not only in rivers, but also in the sea. These animals are distributed at the mouth of the La Plata River (from which they got their name), as well as in the coastal waters of Argentina, Brazil and Uruguay. Unlike other considered species, these mammals lead a nomadic life, migrating in small flocks for wintering, from the mouth of La Plata along the coast of the mainland to the north.

La Plata dolphins feed on various types of fish, both river and sea, including herring, as well as cephalopods and crayfish. In size, these animals are relatively small - up to 170 cm long and weighing up to 35 kg., And their newborn cubs are very tiny, whose length is only 45 cm. An interesting fact is that the females of these river dolphins are noticeably larger than males. La Plata dolphins are painted light brown, and their narrow and very long snout can hold up to 240 teeth! Dolphins belonging to this species are also sociable with humans, like the Amazonian dolphins, but at present very little has been studied.

I would like to note that river dolphins are almost on the verge of extinction. This happens for several reasons: firstly, because these aquatic mammals are losing their habitats, secondly, because people still continue to hunt them, and thirdly, because of their extremely poor eyesight, they are faced with people and various artificial objects, despite the presence special body sound detection - sonar.

Origin story

The superfamily River dolphins is considered the most ancient of all modern mammals related to toothed whales. It appeared on our planet back in the Miocene period in the ocean, and in later periods it was supplanted large predators and competing species. Biologists consider the ancestors of modern river dolphins to be ancient toothed whales - squalodonts (lat. Squalodontidae), which, in turn, descended from land mammals- mesonychid.

According to the oldest remains found, mesonchids lived about 60 million years ago and were very strange, according to modern concepts, appearance resembling a wolf with hooves. These strange looking creatures in what is now the Mediterranean Sea and part of the Asian subcontinent. From ancient toothed whales - squalodonts, modern river dolphins inherited primitive external signs which distinguish them from other aquatic mammals: a very narrow elongated snout, single-pointed wrinkled teeth different size, fewer convolutions of the brain, very wide and short pectoral fins, and instead dorsal fin- low elongated comb. The head of river dolphins is very mobile and is able to turn at an angle of 90 ° relative to the body, which is facilitated by special structure cervical spine.

Other parts of the skeleton also differ significantly from the structure of other modern aquatic mammals and have an appearance characteristic of ancient extinct dolphins. The vision of these dolphins is poorly developed, and the main sense organs that serve to obtain information about the world around us are well-developed organs of touch and an echolocation apparatus that perceives a wide range of sound frequencies. Additional organs of touch for river dolphins are not only numerous skin receptors, but also hard, very sensitive tactile hairs located on the snout, which contribute to hunting in the water and obtaining food by digging it out of bottom muddy sediments.

This is where I would like to end the story about river dolphins, but put not a full stop, but a comma, since in the future we will return more than once to these amazing, sociable and “philanthropic” creatures, but of other species.

Squad of cetaceans. The superfamily includes four living species of dolphins, three of which live in freshwater bodies, and the fourth - La Plata dolphins, lives in the ocean. River dolphins are on the brink of extinction due to loss of habitat, small populations and human hunting. In addition, river dolphins have extremely poor eyesight, which causes numerous collisions with people and those artificial objects that are difficult for them to detect with their sonar.

Links

• Rice, Dale W. (1998). Marine mammals of the world: systematics and distribution. Society of Marine Mammalogy Special Publication Number 4. 231 pp.

Wikimedia Foundation. 2010 .

• Division (Tatarbunar region)
• ORM

See what "River Dolphins" are in other dictionaries:

RIVER DOLPHINS- a family of aquatic mammals of the suborder of toothed whales. Length up to 3 m. 5 6 species, in the rivers Yuzh. Asia and South. America, as well as in the Atlantic approx. off the coast of the South. America. 2 species in the Red Book International Union nature conservation and natural resources … Large encyclopedic Dictionary

RIVER DOLPHINS- (Platanistidae), a family of toothed whales. Length 1.5 3 m. Pectoral fins short and wide. Instead of a dorsal fin, a low crest. The snout is strongly elongated and narrow. The teeth are numerous (from 104 to 242), with curved and widened roots. Good… … Biological encyclopedic dictionary

river dolphins- a family of aquatic mammals of the suborder of toothed whales. Length up to 3 m. 5 6 species, in the rivers of South Asia and South America, as well as in Atlantic Ocean off the coast of South America. 2 species in the IUCN Red List. * * * RIVER DOLPHINS RIVER DOLPHINS,… … encyclopedic Dictionary

river dolphins- upiniai delfinai statusas T sritis zoologija | vardynas taksono rangas šeima apibrėžtis Šeimoje 4 gentys. Kūno masė - 40 120 kg. atitikmenys: lot. Platanistidae engl. fresh water dolphins; river dolphins vok. Flußdelphinartige; Flußdelphine eng.… … Žinduolių pavadinimų žodynas

river dolphins- (Platanistidae), freshwater dolphins, a family of mammals of the whale order. 4 genera, each with 1 species. AT South America 2 endemic species: Amazonian dolphin, or inia (Inia geoffrensis), in the basins of the river. Orinoco and the Amazon, and the Laplata dolphin ... ... Encyclopedic reference book "Latin America"

river dolphins- (Platanistidae) family of mammals of the suborder of toothed whales. Length up to 3 m, weigh up to 225 kg. There are single hairs on the muzzle. The pectoral fins are short and wide, the dorsal fin is in the form of a low triangular ridge. The beak is very ... ... Great Soviet Encyclopedia

RIVER DOLPHINS- a family of aquatic mammals subtr. toothed whales. Length up to 3 m. 5 6 species, in the rivers Yuzh. Asia and South. America, as well as in the Atlantic. OK. off the coast of the South. America. 2 species in the IUCN Red List... Natural science. encyclopedic Dictionary

Family of river dolphins- Already in 1819, A. Humboldt published his observations about one dolphin found in the fresh waters of South America, but did not describe this animal in detail. Desmarets in next year received this animal from the Lisbon Museum and compiled it ... ... Animal Life

DOLPHINS- 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- Atlantic bottlenose dolphins. 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. ... ... Illustrated Encyclopedic Dictionary

Niramin - Nov 26th, 2015

Dolphins are mammals of the dolphin family from the order of cetaceans. There are about 40 types of them. by the most close-up view considered a killer whale.

What do dolphins look like

They have a naked streamlined body, an elongated muzzle, and a pointed dorsal fin. Eyes small, lacking acute vision. Skin color can be of two types: monophonic - gray, color pink, or contrast - when large plots colored in black and white.

Depending on the species, there are different weight: from 40 kg to 500 kg. The body length reaches 1.2 m, while the killer whale can be up to 9 m and weighing 7.5 tons.

They can not sleep for up to 5 days, this does not affect their health. If they sleep, then very little. At long sleep they can suffocate and die. When they rest, one half of the brain is asleep, the other half is awake, then they can breathe.

Dolphins are warm-blooded animals. They have a human body temperature of 36.6°C.

They have echolocation - they determine the location of an object by capturing the reflected sound wave. They communicate between relatives with sounds of various durations, they warn of impending danger with sound signals.

Where do dolphins live

They live in almost all the seas of the world and in shallow tropical latitudes of the oceans. You can also meet in the Black Sea. Only 5 species of river dolphins live in the rivers.

Dolphin nutrition

They feed small fish- anchovies, sardines, squids, crustaceans. The killer whale prefers walruses, seals and sea ​​lions. Interestingly, in the presence of 40 teeth, they swallow all prey whole, without chewing.

Reproduction and lifespan of dolphins

Mating takes place throughout the year. Pregnancy is carried by a female dolphin, depending on the type of animal, from 9 to 16 months. Only one baby is born. Mom immediately pushes the newborn to the surface of the water so that he takes his first breath. They are fed with mother's milk for six months.

The maximum life expectancy is 50 years. In captivity, their life is reduced to 25 years, as animals are often used to perform acrobatic stunts in the dolphinarium.

See gallery of photos of different dolphins:

Photo: Long-beaked dolphin

Photo: Long-nosed common dolphin

Photo: Whale Dolphins

Photo: killer whales

Photo: Large-toothed dolphin

A photo: colorful dolphins

Photo: Gray Dolphin

Photo: bottlenose dolphins

Photo: Beakless dolphins

Photo: Humpback Dolphin

Photo: Grindy





Photo: Dolphins frolicking

Video: Diving and dolphins is an explosive positive!!!

Video: Dolphins bring POSITIVE from the eternal "smile", friendship, fidelity.

Video: Tenerife, Canary Islands. Puerto de la Cruz. Loro park. Killer Whale Show Part 1

Video: Grinds

(Platanistidae)

family of mammals of the suborder of toothed whales. Length up to 3 m, weigh up to 225 kg. There are single hairs on the muzzle. The pectoral fins are short and wide, the dorsal fin is in the form of a low triangular ridge. The beak is very long and narrow. The teeth are numerous (from 104 to 242) with curved and widened roots (in the Gangetic susuk, the front teeth are sharply enlarged). Hearing and echolocation are well developed, vision is poor (the susuk does not have a lens). R. d. live in the rivers of South America and South Asia, 4 genera with 4 species: Inia amazonica, Gangetic susuk (Platanista gangetica, Ganges River, Brahmaputra), Chinese lake dolphin (Lipotes vexil lifer, Dongting Lake) and Laplat dolphin (Pontoporia blainvillei, lives on the La Plata River and off the coast of Brazil, Uruguay and Argentina between 30 and 45 ° S). R. d. feed on benthic invertebrates and fish. Susuk pregnancy lasts 8-9 months

A. G. Tomilin.

• - The most ancient family of modern toothed whales ...

  Biological Encyclopedia

• - Already in 1819, A. Humboldt published his observations about one dolphin found in the fresh waters of South America, but did not describe this animal in detail ...

  Life of animals

• - aquatic mammals of the suborder of toothed whales, closely related to porpoises ...

  Collier Encyclopedia

• - Dolphin subfamily. Most have a dorsal fin, the muzzle is extended into a "beak", the teeth are numerous ...

  Biological encyclopedic dictionary

• - subfamily sea. mammals toothed whales. Length 1.2-10 m. Approx. 50 species, widely distributed. D. are often kept in aquariums where they can breed. Easily trainable...

  Natural science. encyclopedic Dictionary

• - top bronze artillery pieces of the former designs, in the middle of their length, there were two brackets that looked like the letter D. D. were assigned to pass a rope or chain through them, which served to lift ...

  Encyclopedic Dictionary of Brockhaus and Euphron

• - a family of mammals from the order of cetaceans, suborder of toothed whales. D. are characterized by the presence in both jaws of a fairly significant number of homogeneous conical teeth ...

  Encyclopedic Dictionary of Brockhaus and Euphron

• - a subfamily of mammals of the dolphin family of the order of whales. The usual body length is 1.2-3 m, in some species up to 10 m. Most D. have a dorsal fin, the muzzle is extended into a “beak”, and there are numerous teeth ...
• - a genus of mammals of the dolphin family of the suborder of toothed whales. The body of K. d. is thin, the head is small. Above the upper jaw there is a low frontal protrusion. There is no dorsal fin, like right whales...

  Great Soviet Encyclopedia

• - a family of mammals of the suborder of toothed whales. Length up to 3 m, weigh up to 225 kg. There are single hairs on the muzzle. The pectoral fins are short and wide, the dorsal fin is in the form of a low triangular ridge...

  Great Soviet Encyclopedia

• - a family of toothed whales. Length 1.2-10 m. Over 50 species, mainly in moderately warm, including fresh, waters. Most are fast-swimming herd animals...

  Modern Encyclopedia

• - subfamily marine mammals suborder of toothed whales. Length 1.2-10 mm. OK. 50 species, widely distributed. Dolphins are often kept in aquariums where they can breed. Easily trainable...
• - a family of aquatic mammals of the suborder of toothed whales. Length up to 3 m. 5-6 species, in the rivers Yuzh. Asia and South. America, as well as in the Atlantic approx. off the coast of the South. America...

  Big encyclopedic dictionary

• - dolphins pl. A family of marine mammals of the suborder of toothed whales...

  Dictionary Efremova

• - Two handles on the middle part of the gun...

  Dictionary of foreign words of the Russian language

"River Dolphins" in books

Dolphins

by Fischel Werner

Dolphins

From the book Do Animals Think? by Fischel Werner

Dolphins Cetaceans (Cetacea) can be found in almost all seas. These include not only huge whales, but also much smaller dolphins, which will mainly interest us. Whales are descended from land mammals, most likely

The first dolphins

From the book Dolphin Man by Mayol Jacques

The first dolphins It happened in the Red Sea. I was seven years old. On the steamboat, we sailed with the whole family from China to France. My brother and I were on the lower bridge, a few meters from the mirror-like surface of the sea, in the company of the chief onboard mechanic, who was always ready

Humans and Dolphins

From the book Faina Ranevskaya. Psychoanalysis of the outrageous housekeeper the author Vashkevich Ella

Humans and Dolphins - Do you love animals? - unexpectedly asked Ranevskaya. - It depends on which ones, - the Psychologist admitted. - For example, I like dogs more than cats. - No, I mean just animals. Wild, - explained Ranevskaya. - Not those who are considered friends

Reeds and dolphins

From the book Just poured author Burkin Yuly Sergeevich

Reeds and dolphins I here, I remember, told what an idiot I was at the beginning of my journalistic career. But, by the way, there are boobies worse than mine. Several girls from my group went to Odessa for practice, to the newspaper "Odessa Rabochiy". And when they returned, they told

What do dolphins drink?

From the book The Book of General Delusions author Fry Stephen

What do dolphins drink? Dolphins don't drink at all. The dolphin is like an animal in the desert with no access to fresh water. He receives liquid from food (consisting mostly of squid and fish), as well as burning fats in his body, as a result of which water is released. Dolphins are the same whales;

50. Dolphins

From the book We are from underwater space author Kasatonov Valery Fedorovich

50. Dolphins Navy USSR Kalganov Viktor Andreevich phone rang. "Russian Otto Skorzeny" called to

fighting dolphins

From the book Personal Brand. Take care of your reputation before others do author Sitkins Patrick

Fighting Dolphins I played football. AT student years Patrick was a member of the baseball team. When he was a freshman at the University of Jacksonville, the baseball season that year was very busy, with the university team playing games at the highest level.

From the book Infobusiness at full capacity [Doubling Sales] author Parabellum Andrey Alekseevich

Look, dolphins! You must understand what your the target audience and how you will "play" with it: manage, direct - call it what you want. Plan for sharp turns. The correct form of training will bring the appropriate results, and effective training

Acrobat Dolphins

From the book The Complete Encyclopedia of Our Delusions author Mazurkevich Sergey Alexandrovich

Acrobatic Dolphins Many of us have seen flocks of dolphins jump out of the waves with graceful and coordinated jumps. Why do dolphins need such acrobatics? Many children think that dolphins play like this. Perhaps the children are right about something, just like the scientists,

Dolphins

From the book Big Soviet Encyclopedia(DE) author TSB

Dolphins

From the book Encyclopedic Dictionary (G-D) author Brockhaus F. A.

river dolphins

From the book Great Soviet Encyclopedia (RE) of the author TSB

Kay and the Dolphins

From book Inner world injury. Archetypal Defenses of the Personal Spirit author Kalshed Donald

Kay and the Dolphins Those psychotherapists who have worked with traumatized patients quite often experienced happy moments when they discovered the amazing powers of the psyche to protect life, or, more precisely, they could

Dolphins

From the book What he doesn't know modern science author Team of authors

Dolphins Execution cannot be pardonedThe dolphin is the only marine animal that can make friends with a person. One of the first about such amazing friendship tells in his natural history» Pliny the Elder. In the Mediterranean, on the northern coast

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- primitive signs 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 they 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 eats freshwater shrimp and fish burrowing into the silt, which he catches by probing the bottom with his very long jaws. Surprisingly, this animal usually swims on its side.

The Laplata dolphin (Pontoporia blainvillei) is unique among the species of the Platanistidae family for several reasons. He lives not only in major river La Plata in South America, but also leaves it in purely marine coastal waters. Some features of his skeleton are also unusual and good development dorsal fin. Some taxonomists have proposed placing it in the Delphinidae family. This small dolphin feeds on fish, shrimps and cephalopods.

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.