• Interior
• Window
• Walls
• Projects
• The buildings

A person inhales oxygen and exhales carbon dioxide. Human respiratory system. The importance of muscles in breathing processes

. Family of river dolphins consists of Amazonian, Chinese, Gangetic and Lapland river dolphins. Unfortunately for everyone, Chinese river dolphins it was not possible to save: in 2012 the animals were given the status of “extinct”.

Biologists believe that the reason for their extinction lies in poaching activities, the discharge of substances of chemical origin into water bodies, and disruption of the natural ecosystem (construction of dams, dams). Animals could not live in artificial conditions, therefore science does not know many of the nuances of their existence.

Description and features of the river dolphin

Amazon river dolphin a real record holder among members of the river dolphin family: the body weight of river inhabitants is from 98.5 to 207 kg, and maximum length body about 2.5 m.

Pictured is an Amazonian river dolphin

Due to the fact that animals can be colored light and dark colors grey, heavenly or even pink color they are also called white river dolphins And pink river dolphins.

The shade of the lower part (belly) is several tones lighter than the color of the body. The snout is elongated, slightly bent to the bottom, its shape resembles a beak, the forehead is rounded and steep. On the beak there are hairs with a rigid structure, which are designed to perform a tactile function. Eyes are colored yellow, and their diameter does not exceed 1.3 cm.

There are 104-132 teeth in the oral cavity: those located in the front are cone-shaped and designed for grasping prey, the rear ones are stocky, for performing the chewing function.

The fin on the back of the Amazonian river dolphin replaces the crest, the height of which ranges from 30 to 61 cm. The fins are large and wide. Animals are capable of performing jumps over 1 m in height.

The Gangetic dolphin (susuk) is dark gray in color, gradually turning into gray on the abdominal cavity. Length – 2-2.6 m, weight – 70-90 kg. The type of fins is not much different from Amazonian fins.

The snout is elongated, the approximate number of teeth is 29-33 pairs. Tiny eyes are unable to see, and perform a tactile function. Ghanaian dolphins are listed as endangered on the Red List because their population is very small.

Pictured is a Ganges river dolphin

The length of Laplatan dolphins is 1.2 -1.75 m, weight - 25-61 kg. The length of the beak is approximately one sixth of the length of the body. The number of teeth is 210-240 pieces. The peculiarity of this species is its color, which has a brown tint, and these are also characterized by hairs that fall out as they grow older. The fins resemble triangles in appearance. The length of the fin located on the back is 7-10 cm.

River dolphins They have very poor eyesight, but despite this, they are perfectly oriented in a body of water thanks to excellent hearing and echolocation abilities. In river inhabitants, the cervical vertebrae are not connected to each other, which allows them to turn their head at a right angle to the body. Dolphins can reach speeds of up to 18 km/h; under normal conditions they swim at a speed of 3-4 km/h.

The time spent under the water column ranges from 20 to 180 s. Among the sounds produced, one can distinguish clicking, high-pitched squealing, barking, and whining. Sounds are used by dolphins to communicate with relatives, as well as for the purpose of echolocation.

River dolphin lifestyle and habitat

During the daytime river dolphins are active, and with the onset of night they go to rest in areas of the reservoir where the current speed is much lower than in places where they spend their daytime stay.

Where do river dolphins live?? Amazonian habitat river dolphins are the big rivers South America(Amazon, Orinoco), as well as their tributaries. They are also found in lakes and places near waterfalls (upstream or downstream).

During long droughts, when the water level in reservoirs drops significantly, they live in large rivers, but if there is plenty of water due to the rainy season, they can be found in narrow channels, or in the middle of a flooded forest or plain.

Ghanaian dolphins are common in deep rivers (Ganges, Hunli, Brahmaputra), as well as in the rivers of Pakistan, Nepal, and Bangladesh. During daylight hours it dives to a depth of 3 meters, and under the cover of darkness it goes to shallow depths in search of prey.

The habitats of Laplatan dolphins can be rivers and seas. They live near the eastern coast of South America, at the mouth of La Plata. Basically, river dolphins live in pairs or small schools, which consist of no more than a dozen individuals. If food is plentiful, dolphins can create schools several times larger.

River dolphin feeding

They also feed on mollusks (and squid). The rivers in which dolphins live are very muddy; the animals use echolocation to find food.

White river dolphins use their snout to catch fish and also use it as a tool to extract shellfish from the bottom of the reservoir. For prey they go to sections of the river with shallow depths.

They prefer to hunt alone or in small groups. Dolphins take the fish with their front teeth, and then move it to the back teeth, which grind the head first and only after the animal swallows it, crush the remaining part. Large prey is torn into pieces, first biting off the head.

Reproduction and lifespan of the river dolphin

Puberty in river dolphins occurs around the age of 5 years. Pregnancy lasts for 11 months. After the baby is born, the female immediately pushes him out of the water so that he takes his first breath.

The body length of the cub is 75-85 cm, weight is about 7 kg, the body is light colored. grey colour. Soon after the birth of the offspring, the males return to the rivers, and the females and their offspring remain in place (in channels or valleys that were flooded after the water level rose).

Pictured is a baby river dolphin

By giving preference to such places, females protect their offspring from lack of food, predators, and also from aggressive actions on the part of strange males. The offspring stays close to their mother until about 3 years of age.

There are often cases when a female, without completing the lactation process, becomes pregnant again. The interval between matings can be from 5 to 25 months. live river dolphins no more than 16 - 24 years old.

Amazing marine inhabitants, dolphins are mammals, and not fish at all, despite the fact that they spend their entire lives in water element. These creatures are very beautiful and intelligent, therefore they are kept by humans in artificially created aquariums and are used as a very original therapy.

Brief introduction

Dolphins are members of the mammalian order Cetaceans. There are several genera of such animals, differing in structural features and body size, but they are all predators. The habitat of most species of dolphins is seawater; only some representatives of this family are found in rivers.

These animals are distinguished by their ability to develop quite impressive speed in water, they are mobile, curious, and the latter Scientific research proved that their brain is well developed, much stronger than the hemispheres of chimpanzees.

Beautiful sea creatures use fish as food, and the following types are most preferred for them:

• anchovies;
• sardine;
• horse mackerel;
• mackerel.

Dolphins' diet also includes squid and shellfish. Moreover, the diet largely depends on the habitat of the animals being described.

Where do they live?

You can meet these smart mammals exclusively in the water element; they live in almost all corners of planet Earth, except the Arctic and Antarctic. Most of them prefer the expanses of oceans and seas, however, as already mentioned, individual species They are also found in large freshwater rivers.

When telling what climate zone dolphins live in, we can mention:

• moderate;
• subtropical;
• tropical.

At the same time, mammals can travel long distances, leaving one zone and ending up in another.

Examples

There are several genera of aquatic mammals, each of which prefers its own body of water. Let's find out what climate zone dolphins live in various types and childbirth:

• Bottlenose dolphins are common in warm waters Atlantic Ocean, from a temperate to subtropical climate zone.
• Short-headed dolphins prefer a temperate climate zone, some of them swim even further into zones
• Squirrels - common representatives of the family - inhabit the Mediterranean and Black Sea, Atlantic and Pacific oceans, preferring water of warm or moderate temperature.
• Amazon river dolphins live in river mouths and other fresh water bodies, and sometimes even move into flooded forests.

River dolphins are also found in rivers such as the Brahmaputra, Indus, Orinoco, and Ganges. Among the mammals there are also inhabitants of lakes - dolphins were discovered in the Chinese reservoirs of Poyanghu and Dongting.

In Russia

Let's look at the habitat of dolphins in Russia. These are three seas:

• Black;
• Barentsevo;
• Baltic.

In addition, in the Sea of ​​Okhotsk you can sometimes find swimming bottlenose dolphins.

A rare species listed in the Red Book is the Atlantic white-sided dolphin. Prefers the waters of the harsh Barents Sea. The average size this body sea ​​creature small, no more than 3 meters. You can recognize them by the characteristic color of their sides, which are decorated with a long stripe of white or light yellow color. This type It is very cautious, rarely swims up to ships, and therefore has been poorly studied.

The Black Sea is a habitat for three species of dolphins:

• Porpoises (they can also be seen in the Baltic Sea).
• White-sided.
• Bottlenose dolphins.

Let's take a closer look at the peculiarities of life of Russian aquatic mammals.

Or Azovkas are small creatures, their weight does not exceed 30 kg, the body length of an adult is no more than 1.5 m. They feed on small species of fish, less often - invertebrates. To get food, they dive to a depth of more than 70 m, where they can stay for more than 5 minutes.

The Black Sea squirrels are small representatives of their family. Their length rarely exceeds 2 m. They have sharp teeth, the number of which is approximately 200, and thanks to the white color of the belly, they are easily recognizable. This creature can stay in the water for about 8 minutes, and jumps out of it to a height of more than 5 m.

Finally, bottlenose dolphins are the largest representatives of the dolphin family. They are protected, but once a year several of these mammals can be caught for aquariums.

A selection of interesting facts

We looked at what climate zone dolphins live in. The answer is in the tropics, subtropics and temperate zones. We invite you to familiarize yourself with a number of interesting facts related to these mammals:

• Communication between these unusual creations of nature occurs through ultrasound, but they perfectly imitate the voices of other living beings, including human voices.
• Dolphins have complex emotions, they can feel compassion and have fun.
• Despite the fact that the dolphin's jaw has more than a hundred teeth, they do not chew their food, but swallow it whole.
• They can recognize their reflection in the mirror.
• Some species are able to stay awake for more than 5 days without harm to health.
• Females bear offspring for 9-16 months, always giving birth to one baby, which may not sleep for 30 days, forcing the mother to remain awake for a long time.
• If in the waters of the seas and oceans mammals live up to 50 years, then in captivity their lifespan is reduced by more than 2 times.

We looked at what climate zone dolphins live in, and also got acquainted with some interesting facts from their lives. Dolphins are amazingly intelligent creatures, watching which will bring true joy to both children and adults.

where do dolphins live

1. what continent does dnfin live on?
2. In the sea
3. in the seas, the Black Sea, the Caspian Sea, the Barents Sea, the Kara Sea, the Sea of ​​Okhotsk, the Laptev Sea, the Sea of ​​Japan, the White Sea, the North Sea.
4. in the ground
5. The question, to put it mildly, is childish... .
   Suborder
   Toothed whales (Odontoceti)

   Family

   Dolphinidae
   (Delphinidae)
   47 types

   Cetaceans of small size. Body length is 1.1-10 m (in the family one can distinguish small-sized dolphins with a body length of 1.1-4 m, medium-sized ones with a body length of 1.1-4 m, and large ones with a body length of 7.1-10 m). Males are usually larger than females. Sexual dimorphism can also manifest itself in other characters - the shape and size of the dorsal fin, the shape of the pectoral fins. Caudal fin with a deep notch between the blades. Most representatives have a large dorsal fin (sometimes absent) located approximately in the middle of the body. The slit of the blowhole, located on the crown, is horseshoe-shaped and ends facing forward.
   There are no grooves on the throat. The “beak” is well developed, long or completely absent. The body color is varied: monochromatic (gray, black), dark above and light below, or with various light stripes or spots.
   The skull is asymmetrical. The zygomatic and temporal bones are poorly developed in the skull. The proximal parts of the facial bones do not form ridges. The pterygoid and nasal bones are relatively small in size. There are pre- and postorbital processes. The symphysis of the mandible usually does not exceed 1/3 of its length. Rostrum long or short. The width of the bottom and upper jaw approximately the same.
   Dental formula 0-65/2-58
   Most dolphins have homodont teeth small sizes, sometimes large and massive. The upper ones fit into the spaces between the lower ones.
   The cervical vertebrae are fused in various combinations.
   Distributed in almost all seas Globe. Some are distributed very widely, almost all over the world (white-sided delphinus, killer whales), others are more local.
   Mobile animals leading a gregarious lifestyle. The food is varied. Among the representatives of the family one can distinguish ichthyophages, teutophages, teutoichthyophages and sarcophagi.

   Family

   River dolphins
   (Platanistidae)
   6 types

   Gangetic dolphin or susuk (Platanista gangetica)
   Indus dolphin (Platanista indi)
   Amazonian Inia or Bouto (Inia geoffresis)
   Bolivian river dolphin (Inia boliviensis)
   Chinese lake dolphin (Lipotes vexillifer)
   La Plata dolphin (Pontoporia blainvillei)
   The oldest family of modern toothed dolphins. It originated in the Miocene and spread widely in the ocean, but was forced out by competitors and enemies into rivers. River dolphins are characterized by primitive features inherited from their ancestors (squalodonts) - a very elongated (relatively shorter in calves than in adults), narrow snout and a long mandibular symphysis.
   Representatives of this family are relatively small in size. . Body length 1.5-2.9 m. Weight up to 40-123 kg. Females are slightly larger than males. The “beak” is thin and long (1/6-1/7 of the body length), sharply separated from the frontal protrusion. The frontal prominence is sometimes sloping or somewhat more convex. Amazonian and Gangetic dolphins have a cervical joint. The pectoral fins are wide and short, fan-shaped. The dorsal fin is small in the Amazon and Gangetic dolphins and relatively large in the La Plata and lake dolphins. Body color varies greatly from brown or blackish to almost white. Vision is poorly developed or completely absent, for example in Gangetic dolphins, whose eyes do not have a lens.
   The number of convolutions in the brain is less than that of other dolphins.
   They live in rivers, closer to deltas, and La Plata - in the sea.

6. in the seas and oceans!
7. Species of the dolphin family (Delphinidae) live in all open seas and sometimes enter the mouths of large rivers. Representatives of the family of freshwater, or river, dolphins (Platanistidae) have a much more limited distribution. For the most part they inhabit inland fresh water bodies, although some of them can penetrate brackish-water estuaries and even coastal zones of the seas. The family Stenidae includes species that live in the seas, fresh waters or in both of these environments

   Bottlenose dolphins (Tursiops).. Of the species of this genus, the most famous is the Atlantic, or simply bottlenose dolphin (T. truncatus), widespread in warm waters all over the world.

   The white-sided dolphin (Delphinus delphis) from the genus of common dolphins is one of the most common representatives of the family in the Mediterranean Sea. Squirrels inhabit warm and temperate seas around the world. They are usually divided into three subspecies: one in the Atlantic and possibly Indian Oceans, another in the Pacific and a third in the Black Sea. Independent, although closely related forms are sometimes isolated for South Africa, Japan and the Red Sea

   Short-headed dolphins (Lagenorhynchus) are represented by several species: depending on the classification used, their number can reach up to six. Representatives of this genus usually inhabit colder waters than other dolphins, and some species even reach pack ice. One of them, the Pacific striped dolphin (L. obliquidens), is regularly exhibited in several aquariums and is remarkable for its ability to jump over a high-hanging bar

   Continued here: http://www.krugosvet.ru/articles/02/1000203/1000203a2.htm
   What can dolphins do?
   Dolphins possess some skills that were previously attributed only to humans and great apes. Among them are identification of oneself with the reflection in the mirror, a developed system of signal communication, abstract thinking, learning abilities (not to be confused with training!) and the transfer of learned skills between generations

8. Probably in the ocean