Like a river dolphin. River dolphins. Lifestyle and structure of susuk

can migrate along sea coasts.

Amazonian Inia, or Bouto (Inia geoffrensis). Young animals are light gray, but with age they gradually acquire a pinkish tint. Their very long snout is covered with stiff hairs or bristles, which apparently serve a sensory function. Amazon hoarfish 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 molars. Two types of teeth and unfused cervical vertebrae are primitive features for cetaceans. Inia feeds on fish, including those covered with bony plates, and its teeth are often heavily worn, apparently from chewing hard food. According to some reports, inia may have several subspecies. These freshwater cetaceans are common in the Amazon and Orinoco river basins and during floods they even penetrate into flooded forests, where they swim between the trees. When searching for food on the bottom, inias often turn belly up, perhaps because their thick cheeks would otherwise obstruct their view. Studies of the sounds they make have shown the presence of a rich repertoire of pulse signals, including echolocation, used for searching for food and research environment

; however, no monotonal whistles were detected. The Gangetic dolphin, or susuk (Platanista gangetica), lives in Indian rivers Indus, Ganges and Brahmaputra. He is apparently blind, as his eyes lack a lens. However, the animals compensate for this deficiency by developing an unusual cup-shaped depression on the skull, which resembles an enlarged reflector of a flashlight and undoubtedly directs and concentrates echolocation signals. Studies of several living specimens of this species have demonstrated their apparently exceptional echolocation abilities. The Gangetic dolphin is believed to feed freshwater shrimp

The Laplatan dolphin (Pontoporia blainvillei) is unique among species of the family Platanistidae for several reasons. It lives not only in the large La Plata River in South America, but also exits it into purely marine coastal waters. Some features of his skeleton and good development dorsal fin. Some taxonomists have proposed placing it in the family Delphinidae. This small dolphin feeds on fish, shrimp and cephalopods.

Freshwater dolphins are distinguished by the fact that their neck vertebrae are divided, like those of land mammals, rather than fused into a single bone. Some species of this family, in addition to conical teeth, have molar-shaped teeth, i.e. close in structure to the indigenous ones. The dorsal fin is usually very low, in the form of a ridge; only in the Laplatan dolphin it is the same as in the delphinids.

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 lower and upper jaws is approximately the same.
   Dental formula 0-65/2-58
   The teeth are homodont, most dolphins have small teeth, sometimes large and massive. The upper ones fit into the spaces between the lower ones.
   Cervical vertebrae grow together into various combinations.
   Distributed in almost all seas of the 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 large rivers. Representatives of the family of freshwater, or river, dolphins (Platanistidae) have much more limited distribution. For the most part they inhabit inland freshwater bodies, although some of them can penetrate into brackish-water estuaries and even into coastal zones 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.

   Common dolphin ( Delphinus delphis) from the family common dolphins one of the most common members 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

The dolphin is one of the most mysterious and interesting mammals living on our planet. It has been known since ancient times that these mammals can save drowning people and disperse oculi that gather near a person.

In particular, dolphins love children. The main advantages of this species of mammals are their friendliness, sociability or desire to establish some kind of contact with humans. Today we will discuss the topic of where do dolphins live what they eat and how captivity weakens them.

How and where do dolphins live?

The habitat of dolphins can be called the places where they live. Their place of residence can be found in any region globe. Here, everything will depend on the type of dolphin, some of them can live only in certain places. One of the species of dolphins is bottlenose dolphin or simply big dolphin.

Bottlenose dolphins are very common and can be seen in many places. Quite a large number of bottlenose dolphins are found in the waters of the Pacific, Indian and Atlantic Oceans, they can be seen in seas such as the Mediterranean, Red and, of course, Black. Places of residence various types Dolphins can be close to the coastline, or right in the ocean shelf zone.

Migration of dolphins seems to be a frequent occurrence, which is associated with the search for an additional source of food. In the same case, if in any area there is enough food for these mammals, then they take root there for a very long time.

For example, consider the bottlenose dolphin. They are almost always close to the coastline and rarely migrate. It depends on the amount of food near the shore, and most often it is there in great abundance. Bottlenose dolphins are exactly the type of dolphin that many people are accustomed to imagining. Bottlenose dolphins can often be seen near the coastline, and this type of dolphin can be seen in almost all dolphinariums. Many people who do not think about this issue may have the impression that all dolphins live exactly like bottlenose dolphins, but this is a mistaken opinion.

In fact, many dolphins migrate, especially those that live in the ocean shelf and have a completely different habitat. Most often, they travel in flocks and choose the right routes to find the required water temperature and sufficient food. Dolphins have the ability to swim hundreds of kilometers to find a source of food.

Video story

Dolphin feeding

Most often, dolphins look for fish of the following species as food:

• mackerel
• mullet
• cod
• herring, etc.

Sometimes, when there are no fish, they feed on squid. The diet of dolphins will depend entirely on what fish are available in the area, as well as what season they migrated here.

Dolphins can live not only in various seas and oceans, but also their “habitat” may be captivity, i.e. various dolphinariums. Never before has man been given so many opportunities for open communication with these mammals. Here you can touch them, feed them and, of course, swim with them. But people, most often, simply do not understand how the dolphins themselves suffer in these conditions, because many of them were caught, and thereby taken out of natural environment a habitat.

Dolphins are quite smart and have a high level of intelligence, which is very difficult to develop in captivity. Scientists have long provided a lot of evidence that keeping dolphins in captivity causes them great suffering and greatly reduces their life expectancy. So, in the wild, a dolphin can live up to 50-60 years, but in captivity its life expectancy will be reduced to 30 years.

Currently, many organizations have been created that promote the protection of dolphins and are ardent opponents of all existing dolphinariums.

Now you know how where do dolphins live! We hope that the information presented was interesting for you.

In the suborder of toothed whales, the family of river dolphins is the most ancient. Initially, its representatives lived in the ocean, but due to stronger competitors and numerous enemies, they moved to freshwater bodies. The river species, both in its lifestyle and in appearance, differs from the sea dolphins known to everyone.

Characteristics of the animal

If we compare river dolphin with its marine counterpart, it will become clear that the freshwater one is more primitive.

Family freshwater dolphins represent two monotypic genera inhabiting tropical South American rivers, and two genera inhabiting Indian and Chinese rivers.

Now let's talk about the species of river dolphins known today.

Buto or Amazonian inia

The first Amazonian iniu described in detail French scientist D'Orbigny. Traveling around Peru, he caught this freshwater dolphin and studied his appearance well.

The natives do not hunt rime. Why?

The natives ignore the rime due to the fact that the meat of these river inhabitants is soft and there is almost no fat. Also the reason V large quantities mysterious stories associated with animals. According to one of them, the Amazonian inia is an evil sorceress who can transform into a young beautiful woman with curly locks. In this guise she lures gullible youths and destroys them.

Local residents say that the sorceress appears in the city of Aigues, where she is looking for her next victim. When she captivates a man with beauty, leads him to the river bank, where he hugs the victim, screams loudly and disappears into the watery depths with his admirer.

You can fill lamps with fat, but no one does this. The belief says that a person who does this will go blind or suffer misfortune.

Pliny on the freshwater dolphin

The ancient naturalist Pliny was the first to describe another river dolphin - the susuku. Although descriptions of it contained many inaccuracies, because he could only observe the animal in the water. The main misconception was information about the length of the body. According to the philosopher, it reached 7m. In reality, the freshwater one was no longer than 2 m.

Lifestyle and structure of susuk

• The body of this river dolphin is slender.
• The dorsal fin is semilunar and divided into two lobes, essentially a fold of skin.
• Slightly raised long, thin, beak-shaped muzzle, equal in width along its entire length.
• The upper jaw has a ridge surrounding long and narrow nostrils.

Susuk lives in the river basins of Southeast Asia and the Indus. An experiment conducted by biologist Anderson, who kept the susuk in captivity for 10 days, showed that these animals rise to the surface of the water for a moment every half minute to take a breath.

They feed on crayfish and fish. Pregnancy is expected to last 8-9 months; into the light one cub appears, for a long time remaining under maternal care, he clings to her dorsal fin with his muzzle.

Susuk are rarely hunted, mainly for meat. This meat is especially readily consumed Indian women who have difficulties with childbearing. According to legend, meat helps to get pregnant and bear a child safely. Monks and pilgrims, considering the animal sacred, feed it from their hands.

Chinese dolphin

The Chinese river dolphin became known less than a hundred years ago, in 1918. The animal was discovered in a freshwater lake, and it was different from the marine species already studied.

Laplatan river dolphin

• It can live in rivers and seas.
• The body length of males reaches 1.55 m. In females, the body length can reach up to 1.7 m.
• Weight – 28-35 kg.
• The emerging young are about 45 cm long.
• The snout is long.
• Skin color is pale brown.
• Number of teeth – 210–240.
• It eats fish, crayfish and cephalopods.

The Laplata dolphin is sociable, willingly swims up to fishing boats, and makes contact with humans. live these miniature dolphins at the mouth of the La Plata River and coastal waters Brazil, Argentina and Uruguay (between 30 and 45° S).

Reproduction

The river dolphin reaches sexual maturity at the age of approximately 5 years. Pregnancy lasts 11 months. After the baby is born, the female pushes it out of the water so that it takes its first breath.

The cub is 75–85 cm long, weighs approximately 7 kg, and has a light gray body. After the birth of the cubs, the male return to the river, and the female remains with the offspring in place (in valleys, channels). Females protect their cubs from predators, lack of food, and aggression of foreign males. The cubs stay with their mother until about three years of age.

Often the female becomes pregnant again without completing the lactation process. 5–25 months pass between matings.

Life expectancy is 16–24 years.

Among the diversity of dolphins inhabiting warm waters our planet, there is a group of freshwater or river dolphins. Different types These mammals live in the Amazon, rivers and lakes of China, and rivers of India. Representatives of the river dolphin family are the most ancient among their relatives. They are believed to have a more primitive structure compared to sea dolphins. Their brains have fewer convolutions, a dorsal fin is usually absent, and their heads have a characteristic elongated narrow beak, like theirs. ancient ancestor- squalodont. But the special structure of the cervical vertebrae allows river dolphins to turn their heads in relation to their bodies up to 90º, which their marine relatives lack.

One species of river dolphin is the Gangetic dolphin, or susuk. Some researchers identify two individual species: Gangetic dolphin and small Gangetic dolphin. He lives in the Ganges, Indus, Brahmaputra and their tributaries. The Gangetic dolphin has a light gray color and a long beak, slightly thickening towards the end, and its dorsal fin is practically not developed. But this species is interesting because it is practically blind. Gangetic dolphins have rather small eyes that lack a lens, but have receptors that can detect sunlight. That is, they are able to capture only the light source, everything else is barely distinguishable to them. But if you think about it, this is not surprising. After all, these dolphins live in troubled waters Ganges, in which the concentration of suspended substances is high. Therefore, even with good eyesight, it is difficult to see anything there. So nature decided that these dolphins had no need for acute vision. Similar evolutionary metamorphoses can be observed, for example, in moles, which have also lost their sight as unnecessary. How then do Gangetic dolphins find food and communicate with each other? It's simple. Although these river mammals have a more primitive body structure, they have developed acoustic abilities, like their marine relatives. The ability to echolocation helps them easily navigate in space, hunt and find their own kind.

Unfortunately, in recent decades, the number of representatives of this amazing view is shrinking. According to rough estimates, their number is only a few thousand individuals. Today, this dolphin is classified as an endangered species. But this happens not because of hunting for these animals (it is almost never carried out), but because of changes in their traditional habitats. The fact is that due to the construction of hydroelectric power stations on the rivers of the region, the habitat of these dolphins was divided into several areas. For example, the Ganges River dolphins were divided into four isolated populations after the construction of dams. An international group of scientists is developing measures to build bypass channels for dolphins to correct the situation. Therefore, we can hope that this species will not be threatened with extinction in the near future.