Among mammals, only cetaceans are true aquatic animals. They live in almost all seas and oceans. the globe and in some rivers and lakes of Asia and South America. permanent residence in aquatic environment left a strong impression on appearance cetaceans and led to the emergence of very special adaptations in them.
The sizes of these animals range from 1 to 33 meters, and weight - from 30 kilograms to 140 tons. The shape of their body is elongated, torpedo-shaped, well streamlined. Hind limbs have disappeared, only in some representatives they are found in the form of rudimentary formations, and the anterior ones have turned into paddle-shaped pectoral fins- Rudders of depth, turns and brakes. The main organ of movement is the tail, equipped with powerful muscles, slightly flattened laterally, the "stem" of which ends in a triangular caudal fin with horizontally arranged lobes. In addition, most species develop a dorsal fin. All whales are deprived hairline, sebaceous, sweat, salivary glands; in connection with the aquatic way of life, their auricle also disappeared and other changes occurred in the structure of the body.
Systematically, cetaceans are divided into two suborders - baleen and toothed whales. The differences between them are significant and quite distinct. They relate to a number of structural features of the skull and skeleton, the protein composition of the blood serum, the characteristics of the respiratory and digestive systems. This gives grounds for some researchers to consider baleen and toothed whales descended from different roots and elevate them to the rank of independent orders. However, an ultramicroscopic study of the structure of their cell nuclei showed a great similarity in the morphology of chromosomes, which definitely supports the hypothesis of the origin of cetaceans from a single root. The ancestors of cetaceans were undoubtedly some very ancient land mammals. Whether these were ancient insectivores or primitive carnivores (creodonts), or ungulates, it is difficult to say. On this occasion, paleontologists and taxonomists are still arguing. Cetaceans as a detachment may have separated even in the Cretaceous, that is, about 100 million years ago.
115. Bowhead whale - a representative of baleen whales. The huge head makes up at least a third of the body of the animal. Numerous horny plates, or whalebone, are visible in the mouth, which serve as a filtering apparatus for the whale.
Baleen whales are characterized primarily by the complete absence of teeth (they are present only in embryos) and the development in the oral cavity on the expanded palatine processes of the maxillary bones, one hundred and thirty to four hundred horny plates on each side of the jaw. In smooth whales, these plates hang down in oral cavity and thanks to the horn fringe that turns them off along the lower edge, they serve as a filtering apparatus. With the help of this "sieve" and a powerful tongue acting like a piston, animals filter out various planktonic organisms from the water mass that has fallen into their mouths, which they feed on. To baleen whales There are nine species that make up three families: gray whales, right whales and striped.
2013 is declared the Year of Protection in Russia environment. In our country, there are many dates associated with the protection and protection of the animal, flora, water, earth, air and man. Individual events and holidays of the year will be discussed on the Ecological Page. It is intended for a wide range of readers, teachers, educators.
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It has been celebrated since 1986 and is also called Whale Day. It is considered a day to protect not only whales, but also all marine mammals and other living creatures that live in the seas and oceans. On this day, after 200 years of merciless extermination, the International Whale Commission introduced a ban on whale fishing. It is still in effect today and means that whale hunting is prohibited worldwide, as is the trade in whale meat. After the prohibition of commercial whaling, the number of some species of whales began to recover. Currently, only aboriginal whaling is permitted solely to meet the needs of the indigenous population, as well as the removal of whales for scientific purposes. Many of the marine mammals are endangered and are listed in the Red Book. Russian Federation and International Union nature conservation.
Why are they called that?
These inhabitants of the sea are true mammals: they have a four-chambered heart; they are warm-blooded; females give birth to live cubs and feed them with milk; have hair on their skin.
Mammals can live underwater, but they breathe with lungs, not with gills like all fish. Based on this, it becomes clear that mammals cannot stay under water for a long time. They need to constantly rise to replenish the supply of air in the blood. It is believed that marine mammals once lived on the surface of the earth. Some sea creatures They can live both in water and on land.
Who are the marine mammals?
Detachment cetaceans, which include whales, dolphins and porpoises
. Siren Squad including dugongs and manatees. Representatives of the predatory order, where they include otters and sea otters. Pinnipeds, including seals and sea lions
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How long can mammals go without breathing?
marine mammals may 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. The seal stays under water for 15 minutes, diving to a depth of 150 m. The Arctic Weddell seal dives to a depth of 600 m for 70 minutes.
What do marine mammals eat?
Marine mammals, like land mammals, are predators and herbivores. For example, sirens are the only vegetarians among marine mammals, while whales and dolphins are predators. Herbivorous mammals feed on various algae, and predators need animal food - fish, crustaceans, mollusks or small seals.
What is the largest marine mammal?
The largest marine mammal is the blue whale. Due to its size, it is listed in the Guinness Book of Records. The average length of a giant is 25 meters. BUT average weight- 100 tons. Despite their intimidating appearance, whales are not dangerous to humans, as they feed exclusively on fish and plankton.
What is the most dangerous marine mammal?
The most dangerous marine mammal is the killer whale. 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.
What is the friendliest marine mammal?
The most human-friendly marine mammal is the dolphin. There are many cases when dolphins rescued people who got into a shipwreck. Dolphins never attack people. Dolphins are very smart and scientists have found that their brains can be even more developed than the human brain. Dolphins are used in the treatment of childhood diseases. A person grateful to this wonderful animal immortalized it in monuments.
like this interesting creatures are marine mammals. They are majestic and amazing. They have a huge size and they know how to communicate with each other. Another characteristic of them is that they are peaceful and live their lives as families, caring for and loving the members of their group.
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Bibliography
- Bogatyryova, N. A. In the kingdom of Neptune: script / N. A. Bogatyryova // Pedagogical creativity. - 2008. - No. 12. - P. 7–8.
- Bulvanker, V. About whales and baby whales // From a cat to a whale / V. Bulvanker. - L., 1991. - S. 62-66.
About monuments to whales and dolphins.
- Geek, E. Smaller brothers on pedestals: monuments to animals for services to people / E. Geek // Light. - 2010. - No. 4. - P. 39–42.
- Dozier, T. Whales and other marine mammals / T. Dozier; per. from English. L. Zhdanova. - M., 1980. - 129 p.
- Zhukov, B. Singing slug / B. Zhukov // Around the world. - 2009. - No. 3. - P. 96-104.
About whales.
- Zotova, L.V. Inhabitants of the underwater world: a play for children aged 6–8 / L.V. Zotova // Books, notes and toys for Katyushka and Andryushka. - 2009. - No. 7. - P. 56–57. (How beautiful this world is).
- Zueva, S. V. Journey to the depths of the sea: a theatrical performance // Read, study, play. - 2007. - No. 5. - S. 78–84.
- Kryukova, N. S. Journey to undersea world: extracurricular activity/ N. S. Kryukova // Leisure at school. - 2002. - No. 3. - P. 14–16.
- Molyukov, M. I. Animals of the Red Book of the USSR / M. I. Molyukov, O. L. Rossolimo. - M., 1989. - 192 p.
- Animal behavior / vol. edited by A. Perminov - M., 2003. - 191 p. - ( Big Encyclopedia nature).
- Ryazantseva, L. M. "In underwater kingdom Neptune”: sea kaleidoscope / L. M. Ryazantseva // Pedagogical Council. - 2012. - No. 1. - P. 9–12.
- Khersonov, A. When dolphins are “put under arms” / A. Khersonov // Miracles and Adventures. - 2012. - No. 5. - P. 56–59.
On the use of dolphins in military affairs.
- Shcherbakova, A. A. Inhabitants sea depths: February 19 - World Whale Day / A. A. Shcherbakova / Books, notes and toys for Katyushka and Andryushka. - 2009. - No. 12. - P. 55–57. - (It's interesting everything in the world).
- [Ecologists and Dolphin Therapy] // Knowledge - force. - 2010. - No. 11. - P. 56.
This and other literature on the topic can be found in the department of periodicals, local history and the methodological department of the Central Bank. A.N. Zyryanova (street Sverdlov, 57).
It is no secret that the seas and oceans are the habitats of the most unusual, beautiful and simply amazing animals. Until now, the seas surprises researchers. Discoveries of incredible animals are being made, their way of life and interactions with each other are being studied.
Among marine and ocean inhabitants there are representatives of all classes of animals, except perhaps birds. And even then, depending on what point of view you look at them. After all, many birds hunt in the water, and penguins generally live in the ocean. But in this article I would like to focus specifically on those who fit the definition of "mammal marine animal."
Fauna of the seas and oceans
Organoleptic and chemical composition the waters in the seas and oceans are almost the same. Water differs only in the content of certain elements and in the concentration of salts. Therefore, their fauna is also extremely similar. The animals of the seas easily enter the ocean, and the animals of the oceans feel great in the seas.
The fauna of these reservoirs is represented by animals of the following classes:
- Shellfish of all kinds.
- Crustaceans.
- Fish.
- Polyps.
- Sponges.
- Hydroid.
- Insects.
- Amphibians.
- Reptiles.
- Mammals.
- Birds.
It's obvious that organic world oceans and seas is extremely diverse and large in terms of biomass. Among the entire fauna, a mammal marine animal deserves special attention. Most often they live both on land and in water. However, there are also purely aquatic inhabitants.
Species diversity of mammals in the seas
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.
- Whales. These include different species: blue, gray, Greenland, sperm whales, humpback, beaked, minke whales and others.
- Orcas. Animals very close to whales dangerous killers sea and ocean areas.
- Dolphins. Different types: bottlenose dolphins, beak-headed, short-headed, porpoises, beluga whales and others.
- Seals. Animals from the genus of seals, the most common is the ringed seal.
- Seals. They include several varieties: lionfish, spotted seals, eared, real, bearded seals and others.
- Elephant seals are of two types: northern and southern.
- Sea lions.
- Sea cows are today the mammalian marine animal that is almost exterminated by man.
- Walruses.
- Seals.
In total, there are over 120 species of various marine mammals.
Signs of mammals
Like land species, marine and ocean animals also have distinctive features, according to which they can be attributed to the class of 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.
Features of the lifestyle of marine animals
Animals of the seas and oceans have a number of adaptations in order to feel confident and safe in the water. For example:
- limbs are converted into flippers for fast movement;
- many of them are powerful sharp teeth(predators and carnivores);
- large body sizes with a thick layer of subcutaneous fat;
- streamlined body shape, increasing the speed of movement;
- the ability to give each other sound signals (for most).
Thanks to such adaptations, marine animals of the ocean coexist perfectly with each other and the outside world. Most often, mammals of the seas try to stay in herds. This is typical for those who cannot protect themselves from large predators except for the flight of otters, seals, lions, seals).
Others, on the contrary, prefer solitude. This is more convenient for hunting and pursuing prey (sperm whales, killer whales, predatory species dolphins and whales).
The lifestyle of marine mammals, with rare exceptions, is diurnal. At night they usually rest. However, there are exceptions (some seals are night image life).
seabed mammals
A mammal is a marine animal that moves along the very bottom of the depths of the oceans and seas - dugong or (siren). This animal is completely harmless, it fully justifies its name, as it feeds exclusively on bottom vegetation.
The sizes are average against the background of other mammals of the seas: about 4 m in length, weight is about 600-650 kg. A person can easily swim next to sea cow and even touch her, stroke her. The animal is very affectionate, obedient and harmless, like a child.
In addition, this animal is one of the oldest on our planet (appeared about 50 million years ago), it is listed in the Red Book. This is perhaps the only representative belonging to the category "animals of the seabed".
The remaining representatives of marine mammals prefer to spend time at the surface or in the water column, rarely sinking to the bottom.
The most dangerous animals in the oceans
The most dangerous ocean animals include:
- killer whales (killer whales). They weigh more than 8 tons, reach a length of 10 m. Merciless killers that feed on large fish, mammals and their own relatives - whales.
- sperm whales. They attack squid, octopus and shellfish giant size, can eat big fish. The weight of the animal is about 50 tons, and the length is over 20 m.
- Sea lions. In appearance, cute and completely harmless animals often attack humans, as they strictly guard their possessions. In addition, they are carnivorous and feed on fish and small animals.
Of course, there are many more dangers in the oceans. However, among mammals marine fauna the most dangerous are the ones listed above. The rest are either herbivores or feed on plankton or small animals.
The largest animals in the oceans
To the most large mammal Animals include the following representatives:
- Blue or - in length reaches 33 m. Its weight varies from 90 to 120 tons. The heart alone weighs over 600 kg!
- Southern sea Elephant- reaches 6 m in length. Weight is from 5 to 6 tons. In addition to their grandiose size, these animals are also predators - dangerous and ferocious. They are able to dive into water to a depth of more than a thousand meters, if they set themselves the goal of catching up with the victim at all costs.
- Walruses reach a length of 4 m and weigh up to 2 tons. Very impressive size for a completely harmless disposition - they feed on small invertebrates, tearing them out of the silt and sand at the bottom coastal zones. Large dormice spend a lot of time in group sleep on the banks of reservoirs.
The most harmless animals of the seas and oceans
As which are the most harmless mammals of the sea and ocean expanses? The answer is known to every schoolchild: of course, bottlenose dolphins! Lovers of swimming with people, friendly and beautiful - they rejoice and play, splash, jump (up to 6 m high!) And bring a lot of fun and pleasure to people.
Also, harmless marine animals include seals, otters, fur seals and some whales.
One of ancient species animals, mysterious and little studied - these are sharks, or, as they are also called, selachia. Many myths and legends surround this representative of the marine fauna and form a prejudice against amazing fish. The systematic study of selachium began during the Second World War, during the battles in the basins of the quiet and Indian Oceans. The task was to find a means of protecting people from attackers. marine predators.
Is a shark a fish or a mammal
The list of these marine predators includes more than 400 species that differ polarly: from the smallest deep-sea, barely growing to 17-20 cm, to the giant - whale shark, a huge 20-meter multi-ton individual.
The name "mammal" speaks for itself. Those animals that feed their young with milk are called "mammals".
The shark does not feed its cubs with milk, in addition, the shark breathes with the help of such a device - “gills”. Shark is a fish.
In size, of course, these predators are comparable to dolphins or some types of whales. But in the maritime kingdom there are many similar in size, but different in content.
AT modern classification The animal kingdoms sharks and rays form a subclass of Sharks, which belongs to the class Cartilaginous fish. cartilaginous fish, mammals, as well as humans, form a single type for a number of similar characteristics - Vertebrates.
Skeleton bony fish composed entirely of bones, in sharks there are only cartilage. A large number of Calcium makes cartilage hard and strong. Curved, impressive size the mouth is placed on the bottom of the head.
The large and soft caudal fin is asymmetrical - the upper lobe is much larger than the lower one. Bony fish move their lateral fins freely, unlike selachians.
Bony fish and shark, what are the similarities and differences
Mammals and a shark, what are the differences
One of unique properties electroreception, the ability to sense electrical and magnetic signals environment. Used to detect prey, orientation in space, to maintain contact with their relatives.
Electroreceptor sensory organs are present in both selachia and rays, as well as in some species. bony fish. Of the mammals, the Australian platypus and, presumably, the echidna can boast of having electroreceptors. Ampoules of Lorenzini - so called electroreceptor apparatus predator, which she successfully uses at the time of the attack.
In the process of evolution, the relief of the Earth changed - oceans arose in place of the land or, conversely, the continents went under the water column. Some forms of life disappeared, others appeared. Only the selachians continued to exist for almost 500 million years. Some representatives of this unique and little-studied species have not changed much.
The largest copy fossil carchadon, the ancestor of the great white shark. Its size was restored from the fossilized teeth found, the size of which is 10–15 cm. It is believed that seven people could fit in its mouth. The smallest living member of the species is pygmy luminous shark only 7 cm long.
Regardless of whether they live exclusively in water bodies, or swim only occasionally, all these mammals are a real miracle of nature. They can be found all over the world, and they are very different from each other. By the way, people often confuse these animals with other aquatic animals. We easily call beavers water lovers, but we often forget that whales are also mammals, and not fish at all.
From dolphins to elk, aquatic mammals play an essential role in their ecosystems and all of them naturally excellent swimmers. How many of these animal species do you know? It's time to test yourself with our selection of the 25 most amazing marine and waterfowl mammals!
25. Amazonian river or freshwater dolphin
Also known as the pink dolphin, white dolphin or inia, this cetacean is found only in fresh waters great Amazon and river system Orinoco. There this mammal is found quite often, although in last years population pink dolphin began to decrease significantly due to the destruction of their habitat (the construction of dams).
24. Ladoga ringed seal
Photo: Alexander Butakov
Ladoga ringed seals- a very numerous subspecies and the smallest seal in the entire Arctic, which is why inexperienced observers often confuse adults with young ones.
23. Canadian or North American beaver
Photo: Steve/Washington
It is a semi-aquatic rodent with translucent eyelids designed specifically for navigating underwater, and incredibly sharp teeth, with which it gnaws through the mightiest trees and builds dams. Beavers play very important role in the life of their habitat and help in its prosperity.
22. Amazonian manatee
Photo: Dirk Meyer
The Amazonian manatee is a rather bizarre looking mammal with two forelimbs and a tail instead of hind legs. It is the smallest of the manatees in nature.
21. Eurasian Otter
Photo: Catherine Trigg
This animal prefers the fresh waters of Europe, feeds on fish and frogs, and sometimes even feasts on small birds.
20. Capybara
Photo: Pixabay.com
The capybara would probably get along well with the African hippo, because it loves the water and mud of the Andean and other South American river coasts. Like hippos, the eyes, ears, and mouth of the capybara are located almost on the very top of the animal's head, allowing it to observe what is happening around it while being almost completely underwater.
19. North American river otter
Photo: Sage Ross
This otter has a water-repellent coat, webbed feet and a long body. By nature, it is simply created in order to pierce the water like an arrow. These funny animals can hold their breath underwater for as long as 8 minutes!
18. Platypus
Photo: Klaus
The first scientists who encountered these funny mammals thought that the beast was not real, and that one of their colleagues was clearly joking. A mixture of duck, beaver and otter is something absolutely incredible. In addition, the platypus is the only mammal that lays eggs. The males of this species are venomous.
17. Hippo
Photo: Pexels.com
They love water so much that the Greeks even called these massive animals "river horses". Despite the external bulkiness, hippos are excellent swimmers, and under water they can do without oxygen for up to 5 minutes.
16. Indian rhinoceros
Photo: Dr. Raju Kasambe
Listed as a vulnerable species (threatened with extinction), the Indian rhinoceros lives mainly in North India and in Nepal. These rhinos have a number of significant differences from their African relatives, and the main one is their unique horn.
15. Water opossum or swimming marsupial rat
Photo: wikimedia.commons.com
The water opossum is the only mammal in which both females and males have a special skin fold (pouch) on their belly. These animals do not like to gather in flocks and rarely live longer than 3 years.
14. Marsh or water shrew
Photo: Tim Gage
This is the smallest warm-blooded waterfowl in the world (average weight is about 13 grams)! The feet of the marsh shrew are hairy, which helps them swim. By the way, shrews are even smaller.
13. water vole or European water rat
Photo: Pixabay.com
Water voles are often confused with common rats, but this mammal belongs to the hamster family, not the mouse family. The European water rat lives in the area of river banks, near lakes and ponds.
12. Moose
Photo: Pixabay.com
Elk is largest representative deer family, and in the water he feels at home. These animals can even dive!
11. Nutria
Photo: Norbert Nagel
It's pretty large rodent from South Africa. Nutria feed aquatic plants, but sometimes they do not disdain shellfish.
10. Walruses
Photo: wikipedia.commons.com
Walruses are typical inhabitants of the Northern Arctic Ocean, and they are incredibly social animals (living in large colonies). Walruses are easily identified by their massive fangs and unique vibrissae (dense whisker-like bristles). Most These mammals spend their lives on the coast, but for their prey they are able to dive to a depth of 55 meters.
9. Dugong
Photo: Julien Willem
This animal is very similar to the manatee, but it is still separated into a separate detachment of sirens. Dugongs are found in Australian waters and East Africa, and in swimming they can spend 6 months in a row.
8. Leopard seal
Photo: Cyfer13
Like the land leopard, sea leopard – bloodthirsty predator. These seals are excellent hunters and sole representatives of their family, feeding on warm-blooded animals.
7. Cuvier's beaked or medium floater
Photo: Chris_huh
Cuvier's beaked beaks are found in almost all oceans and even in some of the most big seas. While hunting, these amazing mammals are able to descend as much as 2000 meters below the water level!
6 California porpoise
Photo: wikipedia.commons.com
This aquatic mammal is on the verge of extinction, but a rare animal was discovered quite recently - only in 1958. California porpoises live in the area Gulf of Mexico, and due to poaching, their population has been extremely reduced in just the last few years.
5. Humpback whale
Photo: Pixabay.com
These giant creatures are known for their unique songs, which can only be heard underwater, of course. Humpback whales weigh about 40 tons and grow up to 19 meters in length, but despite their huge size, they are excellent swimmers and are able to cover considerable distances during their annual migrations.
4. Polar bear
Photo: Adam Bishop
Believe it or not, polar bears are also included in the aquatic mammals. Polar bears are simply made for life in conditions of eternal cold and for swimming in Arctic waters, because they have a fairly thick layer of subcutaneous fat, and their wool perfectly protects against moisture. In appearance clumsy and bulky, these
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