Marine mammals - a combined group of aquatic and semi-aquatic mammals, whose life takes place completely or a significant part of the time in marine environment. This category includes representatives of various systematic groups mammals: sirens, cetaceans, pinnipeds - eared seals, real seals, walrus. In addition to these animals, marine mammals also include single representatives of the families of mustelids (sea otters and sea otters) and bears ( polar bear). In general, about 128 species belong to marine mammals, accounting for 2.7% of the total number of mammals.

Marine mammals are animals descended from land animals, which for the second time connected their lives at a certain stage of evolutionary development with the sea water element. Sirens and cetaceans are descended from the ancestors of ungulates, while pinnipeds, sea otters and the polar bear originate from ancient canids.

Long before the appearance of people on our planet, the sea and the ocean were mastered by marine mammals - cetaceans and pinnipeds. The finds of paleontologists confirm the existence of whales and 26 million years ago in Cenozoic period. In the process of evolution species composition marine mammals has undergone significant changes. Epochs changed and with them the conditions of existence, some species died out, others, on the contrary, managed to adapt and increase their numbers.

Species of mammals living in the seas and oceans are very interesting and diverse both in their way of life and in appearance. Consider the main representatives.

1. Whales. These include different species: Greenland, sperm whales, beaked, minke whales and others.

2. Killer whales. Animals very close to whales dangerous killers sea ​​and ocean areas.

3. Dolphins. Different types: bottlenose dolphins, beak-headed, short-headed, porpoises, belugas and others.

4. Seals. Animals from the genus of seals, the most common is the ringed seal.

5. Seals. They include several varieties: lionfish, spotted seals, eared, real, bearded seals and others.

6 Elephant Seals two types: northern and southern.

7 Sea Lions.

8. Sea cows- to date, a marine mammal almost exterminated by man.

9. Walruses.

10. Fur seals.

As with land species, marine and ocean animals also have distinctive features by which they can be classified as mammals. What animals are mammals? Like all representatives of this class, it is typical for marine and ocean mammals to feed their offspring with milk through special mammary glands. These animals bear offspring inside themselves (intrauterine development) and reproduce it through the process of live birth. These are poikilothermic animals (warm-blooded), they have sweat glands, a thick layer of subcutaneous fat glycogen. There is a diaphragm that allows you to breathe. These adaptations make it possible to confidently attribute all of the above animals to marine and ocean mammals.

Sea lion

Order Pinnipeds

This large animals, having a spindle-shaped body, a short neck and limbs turned into flippers. They spend most of their time in the water, coming ashore only for breeding or for a short rest. About 30 species are known, among them are the harp seal, fur seal and.

harp seal- this is a pinniped animal that does not have auricles, the hind flippers are short, stretched back and do not serve for movement on land. They crawl on land, raking over the surface with their front flippers. In adult seals, the coat is sparse, without undercoat. The young, not yet able to swim, have thick fur, usually white.

The harp seal is an inhabitant of the Arctic seas. Seals spend most of the year in the open sea, eating fish, mollusks and crustaceans. In winter, herds of seals approach the shores and get out onto large, even ice fields. Here the female gives birth to one large sighted cub. The white skin of a seal with thick fur protects it from frost and makes it invisible in the snow. With the beginning of spring, the herd migrates to the north. Seals are hunted for their skins and fat.

Fur seal has auricles and rear flippers used for locomotion. The rear flippers on land bend under the body, then straighten out - the cat makes a jump.

The fur seal lives in Far Eastern seas. Its body is covered with thick fur with a dense, waterproof undercoat. At the beginning of summer, large herds of seals come to the shores of the islands for breeding. The female gives birth to one cub covered with black hair. In autumn, when the cubs grow up and learn to swim, the seals leave the islands until spring. Cats have valuable fur.

Walrus- the largest of all pinnipeds, up to 4 m long and weighing up to 2,000 kg. The walrus has bare skin and no hair. It is characterized by huge fangs, 40-70 cm long, hanging vertically down from the upper jaw. With them, walruses dig at the bottom, extracting various large invertebrates from there - mollusks, crayfish, worms. Having eaten, they like to sleep on the shore, gathered in a tight heap. When moving on land, the hind legs are tucked under the body, but due to the huge mass they do not go far from the water. They live in the northern seas.

Order Cetaceans

It's completely aquatic mammals never making landfall. They swim with the help of a tail fin and a pair of forelimbs modified into flippers. There are no hind limbs, but two small bones located in the place of the pelvis indicate that the ancestors of cetaceans also had hind limbs. Cetacean cubs are born fully formed and can immediately follow their mother.

Blue whale- the largest modern mammal. Individual specimens reach a length of 30 m and a mass of 150 tons. This corresponds to a mass of at least 40 elephants. The blue whale is a toothless whale. It has no teeth and feeds on small aquatic animals, mainly crustaceans. Numerous elastic horn plates with fringed edges hang from the upper jaw of the animal - a whalebone. Having collected water in a huge oral cavity, the whale filters it through the mouth plates, and swallows the stuck crustaceans. Per day blue whale eats 2-4 tons of food. Whales that have a whalebone instead of teeth are baleen or toothless whales. There are 11 known species.

The other group is toothed whales having numerous teeth, some have up to 240 pieces. Their teeth are all the same, cone-shaped, they serve only to capture prey. Toothed whales include dolphins and sperm whales.

Dolphins- relatively small (1.5-3 m long) cetaceans, the muzzle of which is elongated, like a beak. Most have a dorsal fin. There are 50 types in total. Dolphins find their prey using ultrasound. In water, they make clicking sounds or an intermittent high-pitched whistle, and the echo reflected from the object is picked up by the organs of hearing.

Dolphins can exchange sound signals with each other, thanks to which they quickly gather where one of them has found a school of fish. If any misfortune happens to one dolphin, then others come to his aid as soon as they hear alarm signals. The brain of dolphins has a complex structure; there are many convolutions in its cerebral hemispheres. In captivity, dolphins are quickly tamed and easy to train. Dolphin hunting is prohibited.

In the northern and Far Eastern seas, as well as in the Baltic and Black, there lives a white-barreled dolphin no more than 2.5 m long. Its slender body is black on top, the belly and sides are white. On the elongated jaws of the common flank there are more than 150 teeth of the same conical shape. With them, the dolphin grabs and holds the fish, which it swallows whole.

Sperm whale- a large toothed whale. The length of males is up to 21 m, females - up to 13 m and weight up to 80 tons. The sperm whale has a huge head - up to 1/3 of the body length. His favorite food is large cephalopods, behind which he dives to a depth of 2,000 m and can be under water for up to 1.5 hours.

Marine mammals can be underwater different amount time. For example, whales may not breathe underwater for 2 to 40 minutes. A sperm whale can not breathe underwater for up to an hour and a half. How long a mammal can stay under water is affected by the volume of its lungs. Also important role plays the content in the muscles of a special substance - myoglobin.

Marine mammals, like land mammals, are predators and herbivores. For example, manatees are herbivorous mammals, while dolphins and killer whales are predators. Herbivorous mammals feed on various algae, and predators need animal food - fish, crustaceans, mollusks and others.

The most common from marine mammals- This is a Larga seal that lives off the coast and hunts for fish, and for this it sails for considerable distances from the coast. After hunting, he returns to the shore to feed the cubs and rest himself. The Larga seal is gray with brown spots. That is why it got its name. Larga seals can form entire settlements, where they live from several hundred to several thousand individuals.

The largest marine mammal - blue whale. Due to its size, it is listed in the Guinness Book of Records. The average length of a giant is 25 meters. And the average weight is 100 tons. Such impressive dimensions distinguish it not only among marine animals, but also among mammals in general. Despite their intimidating appearance, whales are not dangerous to humans, as they feed exclusively on fish and plankton.

The most dangerous marine mammal- This . Despite the fact that she does not attack a person, she is still a formidable predator. Even the whales are afraid of her. No wonder the killer whale is called the whale killer. In addition to whales, she can hunt dolphins, sea lions, seals and seals, as well as their cubs. There were cases of killer whales attacking elk and deer that swam across the narrow coastal channels.

When killer whales hunt seals, they set up ambushes. At the same time, only the male hunts, and the rest of the killer whales are waiting in the distance. If a seal or a penguin swims on an ice floe, then killer whales dive under the ice floe and beat on it. The victim falls into the water as a result of blows. Large whales are attacked mainly by males. They unite and all together attack the victim and bite her throat and fins. When killer whales attack a sperm whale, they do not give him the opportunity to hide in the depths of the sea. As a rule, they try to separate the whale from the herd or beat off the cub from the mother.

manatees

The friendliest to humans, a marine mammal is a dolphin. There are many cases when dolphins rescued people who got into shipwrecks. They swam up to people, and they clung to their fins, so dolphins delivered people to the nearest shore. It is known that there have been no cases of dolphin attacks on humans. Yes, both children and adults are very fond of these peaceful animals. In dolphinariums, you can watch dolphin performances in the water. By the way, dolphins are very smart and scientists have found that their brains can be even more developed than the human brain.

Killer whale is the fastest marine mammal. It can accelerate to 55.5 kilometers per hour. Such a record was recorded in 1958 in the Eastern Pacific. The killer whale is distributed throughout the oceans. It can be found near the coast and in open waters. The killer whale does not enter only the East Siberian, Black and Laptev Seas.

Some Marine life much larger than land animals. In this material, we will consider the ten largest animals in size and weight that live in the world's oceans.

The length of an adult walrus is 4 m, and the body weight exceeds 2 tons. A distinctive feature of walruses is their huge elongated upper fangs, which are called tusks. The tusks reach 1 m in length and are used by walruses during battles for females, as well as to facilitate climbing onto ice floes. Because of these tusks, the walrus was also given a scientific name, translated from Greek, which means "walking on the teeth."

Despite their formidable appearance, walruses are very shy animals. While resting on land, they put up sentries who closely monitor the situation and warn the entire herd of the danger that has arisen. They are very sociable and constantly supporting each other animals. After the mating fever, when the males can fight for the right to mate with the female, they all bring up the young together, help with feeding.

Walruses live in the north, rookery on the pack ice.


A huge seal growing up to 6.5 m in length and reaching a weight of more than 4 tons. The elephant seal got its name from its proboscis nose. The male elephant seal is extremely aggressive behavior during mating season when, for the sake of mating, he is ready to trample and tear other rivals, not paying attention to anything. Getting into groups and sorting out relationships with each other sea ​​elephants can easily crush young calves or females, which are significantly fewer males. Every year, during the mating season, a significant number of young animals die from strangulation and strangulation, and males die from wounds received earlier than from natural death.

Elephant seals live on the west coast North America and in Antarctica. The Antarctic (southern) elephant seal is significantly larger than its northern counterpart.

8. Saltwater crocodile

- not exactly a marine animal. It lives in the swamps and mangroves of the tropical region, but can sometimes travel by sea, covering distances of 600 km or more. Therefore, it can be seen, for example, off the coast of Japan, although it never lived there and does not live there. The reasons for such long migrations are not fully known. Saltwater crocodiles, which are solitary by nature, have been suggested by some to seek out more secluded habitats, while others have sought food-rich regions. But whatever the reason, such guests in sea bays and gulfs terrify not only local residents but also on local predators. The crocodile easily displaces even sharks from the chosen coastal zones, which simply retreat, unable to oppose anything to the impenetrable armor of the reptile.

This crocodile is the only reptile that grows over 5 m in length. Adult combed crocodiles grow up to 7 m in length and reach a mass of 2 tons.

Adult killer whales are large marine predators. In captivity in aquariums, we see not record specimens, but in nature their length reaches 10 m, and their weight exceeds 8 tons. Every day, adult killer whales require up to 150 kg. meat, and in their search they spend most of their lives attacking all living things that can satisfy their hunger. The killer whale is nicknamed “killer whale” for a reason – it is the largest carnivore on the planet. They are at the top the food chain, preying on others, and large fish.

Killer whales are extremely intelligent animals. They make perfect use of their group skills while hunting. There are well-known and documented cases of attacks on walruses and fur seals that tried to hide on a lonely ice floe. Accelerating towards the ice floe, they raise a high wave, which washes the poor victim into the water, where she is not destined to escape. Killer whales are also the only marine predators that can jump ashore and grab fur seals their favorite prey.

Killer whales live everywhere, but prefer the cool waters of the Atlantic and Arctic Oceans. Most often kept in the coastal strip.

Humpbacks grow up to 15 m, and the maximum recorded length was 18 m. Weight - 30 tons. It would seem that he should have a characteristic hump, but the main distinguishing feature humpback - long pectoral fins and huge "warts" on the snout. The length of the fins can reach 34% of the body length. They play an important role in the life of the animal - they are involved in thermoregulation, increase maneuverability and help in hunting. Humpback whales often hunt in a group, diving under a flock of fish and surrounding it with small air bubbles. Surrounded by such a wall of bubbles, the fish is lost and huddled into a dense lump, which is swallowed by humpbacks, which suddenly appear from the depths.

Buckles of humpbacks and their blows with their tail and fins on the surface are known. They are even able to completely jump out of the water.

Humpback whales live throughout the world's oceans. They often come to the coast for feeding.

It grows up to 20 m in length and reaches a weight of 30 tons. This is a slender whale and can accelerate to a speed of 50 km/h. (according to other sources maximum speed is 25 km / h) in contrast to their more "fat" relatives. The sei whale dives well, plunging to a depth of up to 300 m and remaining under water for up to 20 minutes.

The sei whale was the most important object of commercial fishing, after the man almost destroyed the blue whale and fin whale. Currently, fishing for this whale is completely prohibited.

Sei whale lives in all oceans, preferring warm tropical waters.

The weight of an adult sperm whale reaches 50 tons, and the body length is 20 m. This is the largest representative of toothed whales - unlike baleen whales, they have teeth and hunt fish, cephalopods and, in rare cases, other marine mammals. The sperm whale is known for its huge head, which occupies 35% of its body length. The word "sperm whale" itself comes from " cachola", which means " big head". On a huge head, the whale's mouth looks small, but the impression is deceptive. One of his teeth weighs 1 kg.

The whale lives in all oceans, but avoids cold areas. It keeps far from the coast, where there is a great depth and their favorite prey lives - squids. The sperm whale hunts, among other things, huge giant squids. Fights with them “reward” the whale with characteristic scars from the suckers of these mollusks.

The record length of the bowhead whale was 22 m and a weight of 150 tons. This weight is comparable to the weight of the animal that won the first place in our top, but it is seriously inferior to it in length. But the bowhead whale holds the record for life expectancy. At medium duration life in 40 years, according to some estimates of scientists, this whale can live up to 211 years. Among vertebrates, this is an absolute record, although it was recently discovered that the polar shark lives even longer - up to an unthinkable 512 years.

The bowhead whale spends its entire life in the cold polar waters of the Northern Hemisphere, retreating south from the growing ice in winter, and returning back in the spring. If the whale is caught in ice, it breaks it with its huge body.

Adult individuals reach a length of 27 m and a mass of more than 70 tons. These giants have chosen the open ocean, rarely approaching the shores. They prefer loneliness, although sometimes there are small groups of 4-6 whales. Despite their huge length, fin whales are quite plastic and “slim”. They swim faster and dive deeper than many other cetaceans. The maximum recorded speed of the fin whale is 50 km/h, and the depth of submersion under water exceeds 250 m. Its speed allows it to feed not only on immobile krill, but also on medium-sized schooling fish.

After uncontrolled fishing for fin whales in the middle of the 20th century. the extraction of this whale was completely prohibited. In 2006, Iceland again allowed hunting for him. The modern estimate of the number of fin whales is 50-55 thousand individuals.

Not only the largest modern animal, but also the largest of all that has ever lived on our planet. The maximum length of this giant is 33 meters, and the weight can exceed 150 tons. They live for 80-90 years, and the oldest known blue whale was 110 years old. Like other cetaceans, it feeds exclusively on plankton, consuming 1 ton of it every day.

The uncontrolled fishing of the blue whale has almost completely destroyed it. In the 1960s, its population was estimated at only 5,000 individuals. In a timely manner Taken measures on the protection of the whale gave their results and at present scientists estimate the number at 10,000 heads, which is already enough not to worry about the safety of the species.

The blue whale lives throughout the world's oceans.

Elephant seals have not only an outstanding appearance, but also amazing superpowers. It turns out that these marine mammals hold the record for holding their breath and can dive to considerable depths. Could you go without breathing for two hours? These figures do not even fit in my head, but for sea ​​elephants- this is quite common. How do they do it?

Elephant seals are a genus of large marine mammals that includes only two species: the northern elephant seal and the southern elephant seal. It is noteworthy that characteristic appearance only males have a large nose. These two species are largely similar in lifestyle, but differ in the place of distribution. The northern elephant seal lives off the western coast of North America, and its southern relative lives off the coast of Antarctica.


northern elephant seal

southern elephant seal

It is the southern elephant seal that is outstanding in many ways. It is larger than its northern relative: the weight of males reaches 3-5 tons, although females are much smaller - only 400-900 kg. These amazing marine mammals are capable of diving to depths of up to 1,500 meters, although the average is around 500 meters, which is also impressive. But in order to dive to such a depth, you need to hold your breath. And here, scientists discovered a simply amazing thing: the southern elephant seal is able to not breathe for two hours and still feel great. Of course, 2 hours is an absolute recorded record, and on average, as observations show, this species of elephant seals dives to a depth of 500 meters.

Such superpowers are due to the structure of the body of the southern elephant seals. Elephant seals are inhabitants of cold seas, and their body is 30-40% fat. This circumstance, according to scientists, allows elephant seals to dive to a considerable depth, where the pressure exceeds 10 atmospheres, because fat hardly compresses under pressure.


Other physiological feature elephant seals - a peculiar structure of the nostrils, which open only at the moment of inhalation and exhalation, and when the animal is under water, they are tightly closed. But the most interesting thing in the body of these animals is the structure of the circulatory system.

The heart rate of elephant seals slows down a lot during diving. If on land his heart beats 60-70 times per minute, while diving to a considerable depth, this figure is only 10-30 beats. This reduces the consumption of oxygen, which in the same amount comes only to the heart and brain. Biologists also managed to find out that there are much more red blood cells, which are responsible for transporting oxygen in the body, in the body of sea elephants than in other mammals. These are such amazing animals - southern elephant seals!


What mammals live in the sea?

Mammals are warm-blooded and cannot breathe underwater. However, some of them millions of years ago went in search of food in the sea. Their descendants adapted to the new conditions of life and became outstanding swimmers. Their limbs have turned into fins, and a thick layer of fat has formed that protects them from cold waters. Marine mammals include whales, dolphins, seals, sea cows (sirens) and sea ​​otters(sea otters).

How does the blue whale eat?

The blue whale is the most large mammal of our planet, the length of which reaches 35 meters, and the weight is about 135 tons. However, this giant is quite harmless and feeds on small marine crustaceans called krill. To get enough, he has to intensively absorb krill, in summer - up to 4 tons per day. Blue whale filters crustaceans from sea ​​water with the help of a whalebone - thin 4.5-meter horny plates located on the upper jaw instead of teeth.

Which seals are the largest in the world?

Southern elephant seals are the largest pinnipeds on the planet. Male individuals reach a length of 5 meters and weight up to 4000 kilograms. Females are half the size and lighter. These giants live mainly on the islands around Antarctica. Northern elephant seals are much smaller and live along west coast North America.

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Which of the land animals is a relative of the siren?

Sirens are the only marine mammals that are vegetarian. They eat algae that grows in warm, shallow waters. Atlantic Ocean. It is even hard to imagine that these marine animals are distant relatives elephants. Depending on the species, they reach a length of 2.5-4 meters and weigh 250-1500 kilograms. They are not as big as their earthly relatives. Sirens always keep to coastal and often very shallow waters. Sirens are the manatee and the dugong.

Which mammals can't leave aquatic environment?

Whales and sirens are not able to leave the aquatic environment, although their ancestors, who lived many millions of years ago, could do this. They emerge only on a short time to exhale used air from the lungs and inhale fresh air. Then they plunge back into the depths of the sea.

What marine mammals travel the longest distances?

The record holder in this "discipline" is the gray whale. This animal, which is 13-15 meters long and weighs up to 35 tons, swims from 10,000 to 20,000 kilometers every year. Pacific Ocean. The whale migrates between areas where it feeds and breeds. Since they live an average of 40 to 50 years, one whale in its life overcomes a distance that roughly corresponds to the distance to the moon and back.

What mammal can dive the deepest?

Among all mammals, the sperm whale is able to dive deeper than anyone - up to 1200 meters. There were even individuals who, hunting for cuttlefish, fell to 3000 meters. Sperm whales, whose length is 18 meters and weighs 50 tons, can stay at a depth of up to two hours without rising to the surface for oxygen.

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