Amazing facts about sharks. Interesting facts about sharks for children Three interesting facts about the giant shark

The shark belongs to the phylum chordate, class cartilaginous fish, superorder shark ( Selachii). The origin of the Russian word “shark” comes from the language of the ancient Vikings, who called any fish with the word “hakall”. In the 18th century, dangerous waterfowl predators began to be called this in Rus', and initially the word sounded like “sharks”. Most sharks live in salt water, but some species also live in fresh water.

Shark: description and photo. What does a shark look like?

Due to the diversity of species, the length of sharks varies greatly: small bottom sharks barely reach 20 cm, and the whale shark grows up to 20 meters and weighs 34 tons (the weight of an average sperm whale). The shark's skeleton has no bones and consists only of cartilage tissue. The streamlined body is covered with scales with pronounced relief protrusions, the strength of which is not inferior to teeth, and therefore shark scales are called “skin denticles”.

The shark's respiratory organ is the gill slits located in front of the pectoral fins.

The shark's heart maintains too little blood pressure, so to stimulate blood flow, the fish must move as often as possible, helping the heart with continuous muscle contractions. Although some species of sharks feel great lying on the bottom and pumping water through their gills.

The shark lacks a swim bladder, which all bony fish have.

Therefore, the shark’s buoyancy is provided by a giant liver, which makes up almost a third of the body weight of a predatory fish, low density of cartilage tissue and fins.

The shark's stomach is very elastic, so it can hold large amounts of food.

To digest food, the concentration of hydrochloric acid in the gastric juice is not enough, and then the sharks turn the stomach inside out, freeing it from undigested excess, and what is interesting is that the stomach does not suffer at all from numerous sharp teeth.

Sharks have excellent vision, 10 times greater than human vision.

Hearing is represented by the inner ear and picks up low frequencies and infrasounds, and also provides the balance function of predatory fish.

Sharks have a rare sense of smell and can smell odors wafting through the air and water.

Predators detect the smell of blood in a ratio of 1 to a million, which is comparable to a teaspoon diluted in a swimming pool.

The speed of a shark, as a rule, does not exceed 5 - 8 km/h, although upon sensing prey, the predator can accelerate to almost 20 km/h. Warm-blooded species - the white shark and the mako shark - cut through the water at speeds of up to 50 km/h.

The average lifespan of a shark is no more than 30 years, but sand dogfish, whale sharks and polar sharks can live more than 100 years.

The structure of a predator's jaw depends on the lifestyle and food consumed. The shark's teeth are long, sharp, cone-shaped, with which it can easily rip the flesh of the victim.

Representatives of the gray shark family are endowed with flat and sharp teeth, which allows them to tear apart the meat of large prey.

Tiger shark teeth

The whale shark, whose main diet is plankton, has small teeth up to 5 mm long, although their number can reach several thousand.

Horned sharks, which feed mainly on bottom food, have sharp small teeth in front and a rear row of large crushing teeth. As a result of grinding down or falling out, the teeth of a predatory fish are replaced by new ones that grow from the inside of the mouth.

How many teeth does a shark have?

Comb-toothed sharks have 6 rows of teeth on the lower jaw and 4 rows on the upper jaw with a total of 180-220 teeth. In the mouths of white and tiger sharks there are 280-300 teeth, which are located in 5-6 rows on each jaw. The frilled shark has 20-28 dental rows on each jaw, with a total of 300-400 teeth. The whale shark has 14 thousand teeth in its mouth.

The size of shark teeth also varies from species to species. For example, the size of the teeth of a white shark is 5 cm. The length of the teeth of sharks that feed on plankton is only 5 mm.

White shark teeth

Where do sharks live?

Sharks live in the waters of the entire world's oceans, that is, in all seas and oceans. The main distribution occurs in equatorial and near-equatorial sea waters, near coastal waters, especially in reef areas.

It is worth noting that some species of sharks, such as the common gray shark and the common shark, are able to live in both salt and fresh water, swimming into rivers. The depth of habitat of sharks is on average 2000 meters, in rare cases they descend to 3000 meters.

What does a shark eat?

The food of sharks is quite varied and depends on the specific species and area. Most species prefer marine fish. Deep sea sharks eat crabs and other crustaceans.

The white shark preys on eared seals, elephant seals and cetacean mammals, while the tiger shark swallows everything. And only 3 species - largemouth, whale and giant sharks eat plankton, cephalopods and small fish.

Types of sharks, names and photographs

The modern classification of these ancient fish, which existed hundreds of millions of years ago, identifies 8 main orders, forming about 450 species of sharks:

Carchariformes (gray, carcharidae) sharks(Carcharhiniformes)

This order unites 48 genera and 260 species. The following species are considered typical representatives of the order:

Great hammerhead shark(Sphyrna mokarran )

It lives in the waters of the Atlantic, Indian, Pacific oceans, Caribbean and Mediterranean seas. The maximum recorded length of a hammerhead shark is 6.1 m. The leading edge of their hammerhead is almost straight, which distinguishes them from other hammerhead sharks. The high dorsal fin is shaped like a sickle.

Silk (Florida, widemouth) shark(Carcharhinus falciformis)

Lives in the Mediterranean and Red Seas, found in the equatorial and adjacent latitudes of the world's oceans.

The widemouth shark is characterized by a rather dark color on the back of various shades of gray, blue, brownish-brown with a slight metallic sheen. Colors fade with age. The scales covering the skin of a shark are so small that they create the effect of their complete absence. It reaches 2.5-3.5 meters in length. The maximum recorded weight is 346 kilograms.

Tiger (leopard) shark ( Galeocerdo cuvier)

Lives off the coast of Japan, New Zealand, USA, Africa, India, Australia. The tiger shark is considered one of the most common shark species on Earth.

These large predators reach a length of 5.5 meters. The color of the leopard shark is gray, the belly is white or light yellow. Until the shark reaches two meters in length, transverse stripes similar to those of a tiger are noticeable on its sides. This is where its name came from. These stripes camouflage predatory fish from their larger relatives. With age, the stripes fade.

Bull sharkor gray bull shark (Carcharhinus leucas)

The most aggressive species of shark, common in tropical and subtropical oceans, you can often find this predatory fish in rivers and canals.

These huge fish have a spindle-shaped elongated body, characteristic of gray sharks, and a short, massive and blunt snout. The surface of the body of the blunt-nosed shark is painted gray, the belly is white. The maximum recorded body length is 4 meters.

Blue shark or blue shark (big shark or great blue shark) (Prionace glauca )

It is one of the most common sharks on earth. The habitat of the blue shark is quite wide: it is found everywhere in the temperate and tropical waters of the World Ocean. reaches 3.8 meters in length and weighs 204 kilograms. This species has an elongated, slender body with long pectoral fins. Body color is blue, belly is white.

Heterodontoid (bull, horned) sharks(Heterodontiformes )

The order includes one fossil and one modern genus, in which the following species can be distinguished:

Zebra bull (Chinese bull, narrow-striped bull, narrow-striped horned) shark (Heterodontus zebra)

Lives off the coast of China, Japan, Australia, Indonesia. The maximum recorded length is 122 cm. The body of the narrow-striped bull shark is light brown or white with wide brown stripes, in addition there are narrow stripes on the sides.

Helmeted bull shark(Heterodontus galeatus)

A rare species that lives off the coast of Australia. The skin of helmeted bull sharks is covered with large and rough dermal denticles. The color is light brown, with 5 dark saddle-shaped marks scattered across the main background. The maximum recorded length of the shark is 1.2 m.

Mozambican bull (African horned) shark (Heterodontus ramalheira)

The fish has a body length of just over 50 centimeters and lives off the coast of Mozambique, Yemen and Somalia. The base of the anal fin is located behind the base of the second dorsal fin. The main color of this type of shark is red-brown, with small white spots scattered throughout it. Maximum recorded length 64 cm.

Polybranchiformes(multibranched)sharks(lat. Hexanchiformes)

A primitive order representing only 6 species of sharks, with the most famous:

Frilled shark (frill shark) (Chlamydoselachus anguineus)

This shark has the ability to bend its body and attack its prey in a similar manner. The length of the frilled bat can reach 2 m, but is usually about 1.5 m in females and 1.3 m in males. The body is very elongated. The color of this type of shark is an even dark brown or gray color. They are distributed from the northern coast of Norway to Taiwan and California.

Sevengill (ashy sevengill shark, sevengill) (Heptranchias perlo)

It is slightly more than 1 meter long and, despite its aggressive behavior, is not dangerous to humans. Inhabits from coastal Cuban waters to the coasts of Australia and Chile.

The color of this species of shark ranges from brownish-gray to olive color, with a lighter belly. Some individuals of the ash sevengill shark have dark markings scattered along their backs, and there may be light edging on the fins. Young sevengill sharks have dark spots on their sides, and the edges of the dorsal and upper lobes of the caudal fins are darker than the main color.

Lumniform sharks(Lamniformes)

These are large fish, endowed with a body shaped like a torpedo. The order includes 7 genera:

Gigantic (giant) sharks ( Cetorhinidae)

They have an average length of 15 m, but, despite their impressive dimensions, they do not pose a danger to people. The color is gray-brown with speckles. The caudal peduncle has pronounced lateral keels, and the tail of sharks is sickle-shaped. Giant sharks live primarily in the waters of the Atlantic, Pacific, North and Mediterranean seas.

Fox sharks (sea foxes) (Alopias)

They are distinguished by a very long upper part of the caudal fin, equal to the length of the body. Sea foxes have a generally slender body with small dorsal and long pectoral fins. The color of sharks varies from brownish to bluish or lilac-gray, the belly is light. They grow up to 6 m in length, but are shy and try to avoid meeting people.

Fox sharks are common in the waters of North America and along the entire Pacific coast.

Herrings (lumnaceae) sharks ( Lamnidae)

These are the fastest sharks. A prominent representative of the family is the white shark, which has a body length of up to 6 meters. Thanks to their delicious meat, herring sharks are exterminated for commercial purposes and are also used as objects of sport hunting in the warm waters of the world's oceans.

False sand sharks(Pseudocarcharias)

Pseudocarcharias kamoharai is the only species of the genus. These fish are distinguished by their peculiar body shape, reminiscent of a cigar. The average body length is 1 m; predators are not aggressive towards humans, but when caught, they begin to bite. These sharks live in the eastern Atlantic, Indian and Pacific oceans.

Sand sharks(Odontaspididae)

A family of large fish with an upturned nose and curved mouth. Slow and not aggressive, they are considered theoretically dangerous to humans, although recorded cases of cannibalism most likely relate to gray sharks, with which sand sharks are often confused.

Sand sharks are inhabitants of all tropical and many cool seas. The maximum body length of this shark species is 3.7 m.

Largemouth (pelagic) sharks(Megachasma)

Family Megachasma represented by a single and rare species Megachasmapelagios. Representatives of the largemouth shark species feed on plankton and are not dangerous to people. The body length of this species is up to 6 m in length. These sharks swim off the coasts of Japan, Taiwan and the Philippine Islands.

Scapanorhynchid sharks (goblin sharks) (Mitsukurinidae)

They represent 1 species, which received the popular nickname “goblin shark” for its long beak-shaped nose. The length of an adult individual is about 4 m and weighs just over 200 kg. A rare deep-sea shark species lives off the coast of Japan and Australia.

Wobbegong-like(Orectolobiformes)

A squad consisting of 32 species of sharks, the brightest representative of which is the whale shark (lat. Rhincodon typus), growing up to 20 meters in length. A good-natured animal that allows divers to pet it and even ride on its back.

Most species feed in shallow water on mollusks and crayfish. These sharks are found in warm waters of the tropical and subtropical zones.

Sawtooth sharks(Pristiophoriformes )

The order includes the only family Saw-nosed sharks or saw-nosed sharks (lat. Pristiophoridae), which are distinguished by a long, flat snout with saw-like teeth. The average length of an adult sawnose shark is 1.5 meters. These predatory fish are common in the warm waters of the Pacific and Indian Oceans, as well as off the coast of South Africa, Australia, Japan and a number of Caribbean countries.

Katraniformes (spiky) sharks (Squaliformes)

A numerous order, including 22 genera and 112 species. Unusual representatives of the order are the Southern dogfish, sea dog, or marigold (lat. Squalus acanthias), which can be found in all seas and oceans, including Arctic and subantarctic waters.

Flat-bodied sharks (sea angels, squats) (Squatina)

They are distinguished by a wide, flat body, resembling in appearance. Representatives of sea angels have a length of slightly more than 2 meters, are predominantly nocturnal, and during the day they sleep, buried in the mud. They live in all warm waters of the world's oceans.

Since childhood, we know that a shark is a predatory animal that knows no mercy, which is feared not only by people, but also by the inhabitants of the bottom of the sea. If we turn to simple statistics, the result will be obvious - a shark kills up to two hundred people a year (and mainly through their fault), and a person kills approximately 1 million sharks in 365 days!

So it’s worth thinking about who is harming whom and who is the dangerous predator here. But let’s not talk about the bad stuff and get back to the interesting facts about sharks.

Shark jaw

The teeth of these predators have a unique ability to change as they are used; if a shark’s tooth wears out, it’s not a big deal; it can wait a little and a new one will grow. This is truly wonderful, nature has provided for everything.

After all, teeth are a very important part of life for sharks; they use them to feed and look so scary.

Sharks' sense of smell and hearing

The shark has almost the best sense of smell in the world. She is able to smell just one drop of blood at a very long distance (up to 2 kilometers), and she begins to see her prey only at 5 meters.

Of all species, the white shark has the best hearing, and other individuals of this species hear in the range from 10 to 800 Hertz, which is half the range of human hearing.

Skin Features

In order to move faster, the skin of sharks is lubricated with a so-called special oily secretion, which reduces water resistance and gives the shark a better chance of catching up with its prey.

Females of this species also have thicker and more durable skin. This is because at the moment of mating, the male shark bites the female, and so that no damage remains, or they are insignificant, her skin is much rougher than his.

Shark sizes

One of the largest sharks in the world is the whale shark. Its length can reach 12 meters, and in the rarest cases 14 meters.

And the smallest shark is only 15 and a half centimeters in size. Here is such a strange spread, some are simply huge, while others are disproportionately tiny.

Shark food fever

In such a terrible state, the shark can rush at everything that moves and remains motionless. She feels a monstrous feeling of hunger, which is very difficult to satisfy.

Where it comes from and why it occurs is unclear, but in such a state, even those sharks that are not dangerous to humans can be unpredictable.

Movement speed and sleep

Usually sharks do not move very fast, depending on the species, their speed ranges from 2 to 8 kilometers per hour, but white sharks are striking in their speed and will accelerate at the right moment.

In “turbo” mode, their speed can reach up to 50 kilometers per hour. This is a very convenient ability when hunting and allows the shark to catch up with its prey in any case.

But among these marine predators there is also a very slow species - the Greenland shark. Its speed does not exceed 2.5 km/h.

Another interesting fact about sharks is that it is a very common misconception that a shark must constantly swim to breathe, but this is not true. Some sharks can sleep lying on the seabed, with their eyes open all the time and pumping water through their gills.

Complete the list of interesting facts about sharks by writing what you know in the comments.

Ecology

Basics:

White sharks are the largest predatory fish on the planet. They grow up to 6 meters in length and can weigh more than 2 tons. They have good intelligence and are quite curious. These animals have well-developed senses and an exceptionally well-developed brain that allows them to control these senses. This is why white sharks are at the top of the ocean food chain.

Their gray body allows them to camouflage well on the rocky bottom, and the underbelly of the sharks is white, which is why they received the name “white sharks.” Unlike other fish, sharks have a cartilaginous skeleton instead of bones. The white shark has 300 teeth, and they are arranged in seven rows.

The body of white sharks is ideal for swimming. Its torpedo-like shape and powerful tail allow it to swim at speeds of up to 24 kilometers per hour. When a shark chases prey, it can push its body forward, jumping out of the water. Her attack strategy involves quick, unexpected movements and a death grip with very strong jaws.

White sharks feed mainly on fish - rays, smaller sharks and other fish. When they reach maturity, sharks can attack marine mammals, including seals, sea lions, elephant seals, and also do not disdain carrion - they eat the corpses of large animals, they especially adore fat dead whales. There are known cases of white sharks attacking humans, but sharks were not known to eat people.

White sharks reach sexual maturity at 15 years of age, and they live on average about 60 years.

Habitats:

White sharks live in almost all oceans and seas, although they prefer temperate coastal areas. They can live in the open ocean, or near islands and off the coasts of continents, in cold and tropical waters at depths from a couple of meters to 250 meters. Researchers have noticed that many sharks constantly migrate, for example from South Africa to Australia, from California to Hawaii. They migrate over very long distances.

Security status: vulnerable

White sharks are mercilessly exterminated for their fins, from which they make a delicious soup, and also for their jaws, which are often just hunting trophies. Sharks often die due to becoming entangled in fishing nets, and the younger generation also loses their habitat before reaching adulthood.

The white shark has 6 well-developed senses: smell, hearing, touch, taste, vision and... electromagnetism!

The sense of smell helps them distinguish between substances at the molecular level - 1 part in 10 billion parts of water. For example, a white shark can smell a seal colony 3 kilometers away.

The pores on a shark's face are filled with cells that sense the strength and direction of electromagnetic radiation. They use this sense to navigate the open ocean and to monitor the heartbeat and gill movements of prey.

Most white sharks are not deadly to humans, although they can bite. Researchers say these curious fish usually take a "test bite" and then release a person, but are unlikely to deliberately kill them to eat them.

1. According to researchers, the following sharks most often attack humans: tiger, hammerhead, mako, whitefin, bull, sand, blue, lemon and sea fox.

2. A three-meter shark can swallow an entire side of beef in one go.

3. A variety of objects were found in the stomachs of sharks - for example, bottles, jute bags, postal parcels, shells and grenades, spinning rods and even a large African one there. There are known cases of sharks attacking yachts and fishing boats.

4. It is believed that sharks attack swimmers more often in warm water - above 18 degrees, researchers publish the following figures: "Out of 790 Cases of Attacks, Only 3 Occurred in Water with a Temperature of 18 degrees." And it is concluded that sharks do not attack in cold water. However, any sane person understands that people simply prefer to swim when the water is warm, and swim in warm water much longer than in cold water. And there are fewer sharks in cold seas.

5. Sharks kill, according to various sources, from 80 to 300 people every year. Currently, in most tourist countries, information about shark attacks is not made public. It is impossible to know how many people die in the Red Sea; although from conversations with local residents it is known that only in the area of the Eilat resort 2-3 people die a year - as a rule, those who swim from yachts in the open sea

6. Depending on the species, a shark’s mouth can have from 30 to 400 teeth and they are located in several rows. The force of compression of the jaws of a four-meter shark is 20 kilonewtons.

7. Half of all shark attacks on humans result in death.

8. The shark smells blood from afar. It happened that sharks rushed towards a wounded whale from a distance of several kilometers. The shark begins to examine the prey from about five meters. From a great distance, she only smells and hears the victim.

9. The safest color for a wetsuit is black, without bright stripes. But black suits are not issued - it is believed that the scuba diver must be visible so as not to get lost and not get hit by the propeller. They say bright green flippers are more dangerous than dark blue ones. Some instructors advise women to remove their gold earrings before diving.

10. sharks are less likely to attack a clothed person. Theorists advise that if you get into the water dressed, do not undress and do not take off your shoes. Although in this case you can quickly drown. 11. Sharks generally move at a cruising speed of approximately 8 km/h, but when hunting or attacking, the average shark accelerates to 19 km/h. The mako shark can accelerate to a speed of 50 km/h. The white shark is also capable of similar jerks. Such exceptions are possible due to the warm-blooded nature of these species.

12. Sharks do not have a swim bladder. They maintain their position in the water because the water washes over their fins. If they stop moving, they will drown. They don't have brakes, so they won't be able to stop quickly. 13. For a week, a shark has enough food in the amount of only 3% - 14% of its own weight.

14. Sometimes during a hunt, a shark goes into a “Food Madness.” In a blind rage, she attacks any object that comes her way, be it a sea animal, a person, or an underwater cable.

15. A shark senses one gram of blood dissolved in 600 thousand liters of water at a distance of 500 meters.

16. In 1967, Melbourne resident Henry Boers was swimming near the shore. A shark that suddenly appeared bit off the swimmer's leg. A year later, already with a prosthesis, Henry appeared on the beach again. Having swam to his heart's content, he turned to the shore, when suddenly a warning cry was heard from the patrol boat. Behind the bursa, a shark fin loomed. There was a crunch and the predator swam away with... a denture in its teeth.

17. When attacking, the shark first plunges the teeth of the lower jaw into the body of the victim. The upper teeth cut it like a knife, causing terrible wounds.

18. Smooth compositions such as Brahms' "Lullaby" make sharks fall into a trance.

19. Sharks are sea vagrants. In search of prey, they wander randomly along ocean roads. Sometimes they tag along with some ship from which they generously dump kitchen waste into the water and can accompany it, say, from Lisbon to Hong Kong.

20. Not all sharks are predators. Many feed on plankton, jellyfish, and small fish, such as the giant whale shark.

The white shark, or man-eating shark, is found in the surface coastal and open waters of all oceans of the Earth (except the Arctic). On average, representatives of the species grow up to 4.6 m in length. Life expectancy is estimated at approximately 27 years. Read 34 interesting facts about white sharks...

If a white shark stops moving, it will drown.

A great white shark gives birth to live babies.

The white shark can raise its own body temperature to hunt in cold water.

The great white shark has the strongest bite on Earth - about 18,000 newtons.

White sharks swim only where they know their way around well.

Great white sharks use a serial killer strategy when hunting fur seals.

The average body length of a white shark can be considered 3.7-4.6 meters. The average weight of an adult is about 1000-1200 kg.

The largest white shark measured and witnessed by science experts Ellis and McCosker was caught in 1945 near Cuba. Her body length was 6.4 meters and her approximate weight was 3.324 tons.

Great white sharks have the largest teeth of any living fish. Their diagonal length is about 5 cm, rarely more. They are located in the mouth in 5-7 horizontal rows, but there is only one working row - the first. Each row can have 30-40 teeth, meaning that a great white shark's mouth can hold up to 300 teeth in total.

A complete change of working teeth in a young great white shark occurs in three months, in an adult it takes twice as long – in six months.

Atlantic Ocean. At least a triangle, because many believe that ancient Atlantis is just a myth. Although, who knows, maybe it really existed and someday the remains of an ancient civilization will be found.

Well, today we will talk about the Atlantic Ocean itself, which, by the way, is the second largest body of water on the planet.

If you taste water from all four of the world's oceans, the Atlantic is the saltiest of all, and it is also the youngest in age.

After the legendary Columbus made his journey through it, the Atlantic Ocean became a kind of border between the Old World (Eurasia and Africa) and the New (America).

It received its name in honor of the ancient Greek titan Atlas, who held the sky on his mighty shoulders.

On its territory there is a unique object - the sea, which is the only one in the world that does not have shores. It is called Sargasso, is limited by currents on four sides, and its waters are almost stagnant and completely covered with algae. It was beautifully described in his novel “The Island of Lost Ships” by science fiction writer Alexander Belyaev.

Also on the territory of this ocean there is an “azure hole” - a funnel with a diameter of 305 m, which has clearly defined boundaries, the water in the middle of it is much darker and it seems that its depth is endless, although in fact it is 120 m. It is located 100 km from the city Belize, and gained its fame thanks to the oceanographer Jacques Yves Cousteau.

Although the Atlantic is smaller in area than the Pacific Ocean, fishing here flourishes no worse, and almost more fish are caught than in the world's largest body of water.

The largest island in the world, Greenland, completely covered with ice and snow, is located in the North Atlantic.

The legendary "" sank in the North Atlantic.

It passes through almost all the Earth's climatic zones, and thanks to its warm Gulf Stream, Europe boasts a temperate climate, otherwise it would be much colder there.

Water boils at a temperature of +100 °C. It is this beneficial property of water that allows you to get rid of many harmful microorganisms by boiling for a long time.

Purified water free of all impurities is called distilled. The most interesting and surprising thing about this is that a person cannot drink such water.

Water contains a large number of gases, including oxygen and nitrogen. It is this circumstance that makes it possible for fish and other inhabitants of the seas and rivers to exist calmly in the water and breathe through their gills.

There is dead and living water. It can be obtained by passing an electric current in separate vessels with electrically conductive walls.

Since water contains a lot of dissolved salt, its density increases slightly. For example, in the Mediterranean

Hot water is heavier than cold water. This is explained by the fact that when heated, a large amount of dissolved gases come out of it, which are significantly lighter in density than liquid.

Perhaps the most interesting fact about water is that water expands when it freezes. This is what causes heating systems to burst if warm water is not constantly circulated through them in winter.

Water begins to freeze at zero degrees Celsius. It would be logical to assume that it has the greatest density precisely at this mark on the thermometer. However, water has its greatest density at a temperature of +4 °C.

What is surprising is that its density is maximum at +4 °C, i.e. under such conditions it becomes the heaviest for the same volumes.

Water cannot be compressed with a conventional press. When compressed, water begins to seep through the walls of the press. The same applies to any other substance in a liquid state. But ordinary ice compresses without problems.

Due to the fact that ice easily melts with friction, we can skate without experiencing serious resistance on its surface.

Water, being in different states, reflects light differently. Snow can reflect up to about 85% of the sun's rays, and water only 5%. That is why it is able to store so much energy from the sun's rays.

The blue color of clear ocean water can be explained by the selective absorption of a certain part of the spectrum and the scattering of light in the water.

From school, we know that any substance can be in only 3 states of aggregation: liquid, solid and gaseous. However, scientists distinguish 5 different states of water in liquid form and 14 states of ice.

Some researchers count more than 2,000 structured forms of water.

There are over 135 isotopic varieties of water. Their names are very appropriate: “live”, “dead”, “heavy”, “slippery”, “dry” and “rubber”.

Which water do you think is more likely to turn into ice: hot or cold? A strange question, because it is obvious that it is colder. After all, hot food must first be cooled, and only then allowed to freeze. However, experience has proven that it is hot water that turns into ice faster.

There is still no clear answer to this question, why hot water freezes faster than cold water. This is probably due to differences in supercooling, evaporation, ice formation, convection, or the reason is the effect of dissolved gases on hot and cold water.

There is a natural phenomenon that scientists call supercooling of water. Crystal clear water that does not contain impurities has this property. Even when cooled below freezing, such water still remains liquid. However, as the temperature drops, the water will still turn into ice or boil.

Continuing to cool the frozen clean water, you can notice its miraculous transformations. At -120°C water becomes super viscous or viscous, and at temperatures below -135°C it will turn into “glassy” water. "Glass" water is a solid substance that lacks a crystalline structure, just like glass.

The most popular pet in the United States is the cat. Americans keep 88 million pet cats and 74 million dogs in their homes.

There are cases where cats survived after falling onto a concrete platform from a height of 32 floors (320 meters).

20 muscles are responsible for the functioning of a cat's ears.

A cat spends 70% of its life sleeping.

A cat named Stubbs was the mayor of Talkeetna, Alaska, for 15 years.

And one cat was declared a candidate for the position of mayor of Mexico City in 2013.

Cats can't stand sweets.

On average, cat owners experience strokes and heart attacks one third less often than other people.

The world's longest cat was 121.92 cm tall.

There is tangible evidence that the cat was domesticated around 3600 BC. and 2 thousand before the pharaohs began to rule in Egypt.

A cat's purring can be seen as, in some way, a form of self-medication. It can be either a signal of excitement or complete relaxation and contentment with life.

Likewise, the frequency of a domestic cat's purr is surprisingly consistent with that needed to restore muscle function and bone structure.

Adult cats meow for the sole purpose of communicating with people.

The world's richest cat owns $13 million. He entered into the inheritance left to him by his mistress after her death.

Cats are often lactose intolerant, so let's finally stop giving them milk!

Almost all cats are characters in animated films and are represented as notorious liars.

In the 60s of the last century, the CIA conducted experiments to train a cat as an ideal spy. For this purpose, she had a microphone implanted in her ear and a radio transmitter at the base of her skull. She survived the operation, but was hit by a taxi during her first mission.

A lump of hair in an animal's stomach is called a "bezoar" (the same word has another meaning - "bearded goat").

Cats are usually right-handed, and cats are left-handed.

Cats make about 100 different sounds, while dogs only make about 10.

The cat's brain is 90% similar to the human brain, and to a lesser extent similar to the dog's brain.

The parts of the brain responsible for the emotional sphere in cats and people are almost the same.

The cat's cerebral cortex (which processes cognitive information) contains 300 million neurons. This is almost twice the number of neurons in a dog's brain - 160 million.

Compared to dogs, cats have a longer-term memory, which is greatly activated by performing an action instead of simply watching someone else perform the same action.

Cats have a lower social intelligence quotient than dogs, but they are capable of solving complex cognitive problems when they are particularly inclined to do so.

In Ancient Egypt, it was legally prohibited to kill cats. Mostly due to the fact that by hunting rats, they did not allow them to multiply excessively.

In the 15th century, Pope Innocent VIII ordered the killing of cats, declaring that they had demonic traits.

A cat has five toes on its front paws and four on its hind paws, unless it is, of course, polydactyl, that is, multi-toed.

Initially, sand was used as cat litter, but in 1948 it was replaced by clay, which has more pronounced absorbent properties.

Abraham Lincoln kept four cats in the White House.

When Mary Todd Lincoln was asked about her husband's hobbies, she is said to have answered "cats" without hesitation.

Isaac Newton is credited with inventing the cat flap.

One legend says that cats appeared after the lion on Noah's Ark sneezed and two kittens were born.

A cat can jump to a height six times its own height.

When cats leave their feces unburied, it is a sign of aggression and that they are not afraid of you.

Cats are able to change the intonation with which they meow. They do this with the aim of manipulating people. For example, they often imitate a baby's cry when they need food.

Whiskers help cats explore the world around them if they can touch an object or sense vibrations in the air.

Cats only sweat through the pads on their paws.

The first cat to go into space was a cat from France named Felicette. Having successfully landed after a flight into space, she received another nickname - “Astrocat” or “Space Cat”.

Hearing is the most highly developed sense in cats. They can hear sounds with a frequency of about 64 kHz. For comparison, a person can hear sound with a maximum frequency of 20 kHz.

A cat can turn its ears 180 degrees. In addition, they can move their ears in different directions.

Each individual cat's nose print is unique. In this way it resembles a human fingerprint.

In cats, scent glands are located along the entire length of the tail, on the forehead, lips, chin and under the pads of the front paws.

When a cat rubs against people's legs, it is marking its territory.

Cats lick themselves to get rid of your scent.

In ancient Egypt, after the death of their cat, members of the family to which it belonged would shave their eyebrows as a sign of grief.

It was customary for the ancient Egyptians to place the mummified remains of cats in caskets, which were elaborately carved sculptures, and bury them either in a family tomb or in a special pet cemetery.

In ancient Egypt, cats were believed to be mythical creatures and sacred animals.

Residents of the United States believe that meeting a black cat is a bad omen, while citizens of the United Kingdom and Australia believe that it is good luck.

Most cats hate water because their fur gets wet quickly and makes them cold.

The Egyptian Mau is the oldest cat breed. Cats of this breed are the fastest among their purebred counterparts. Translated into Egyptian, the word “cat” sounds like “mau”.

Only 11.5% of people consider themselves big cat lovers.

In addition, 11% of cat lovers have an unsociable personality and are introverts.

Male cat owners are more popular with women because they are more sensitive.

Among cat owners, people with higher education, according to statistics, are 17% more common.

When your cat brings home a strangled mouse or bird, it means that she wants to demonstrate her superiority over you as a hunter.

Cats have reduced daytime vision, but at night they need seven times less light to see well.

Video 10 facts about great white sharks

Fact 10

If anyone wanted to turn off the Sun, the temperature on Earth would drop to -18 degrees within a week. A year later it reached -75 degrees. It's certainly too cold and dark to live in so hands off the light switch!

Fact 9

The sun is getting warmer and brighter. It is expected to brighten 10 times! However, only in a billion years. This could also mean that water on earth could become scarce. Will wait. Now number 8!

Fact 8

Hydrogen makes up 72% of the mass of the sun, 26% helium and several other substances, but taken together this gas mixture makes up 99% of the total mass of the solar system. This is incredible!

Fact 7

The sun is a valuable source of energy. This energy heats not only the Earth, but the entire solar system! Every second, 700 million tons of hydrogen are converted into helium. This is extremely interesting!

Fact 6

The surface of the sun itself is cooler than its system, about 6000 Kelvin. The atmosphere can reach temperatures of up to 10,000 kelvins, and the solar corona (outer layers of the atmosphere) 1,000,000 kelvins. By the way, the corona can only be seen during a solar eclipse.

Fact 5

The Sun is located about 25 light years from the center of our galaxy. Our galaxy is huge. This is how our solar system traces a circle around the center of the galaxy in only 240 million years. Although its speed of movement is almost 800 thousand kilometers per hour.

Fact 4

As already mentioned, the Sun consists of gases. Therefore, different parts of the Sun rotate at different speeds. The regions of the equator rotate approximately every 25 days, and at the poles about 26. I wonder how it all holds together?

Fact 3

There are places of eternal light on several planets and moons. This is where the sun never sets. These planets, as you might guess, rotate with a certain angle of inclination relative to the Sun. Always seeing the Sun is just a dream.

Fact 2

The sun is now in its middle age. Astronomers estimate that this star formed more than 4.5 billion years ago. In 5 billion years it should turn into a red giant and then into a white dwarf. People are bad, it’s good that we still have time.

Fact 1

If we want to generate energy from the sun, we will have to detonate 100 billion tons of dynamite every second. This is already beyond the realm of possibility.

34 facts about the life of white sharks

Great white sharks live in many coastal temperate and warm waters that are rich in food. They are found almost along the entire eastern and western coasts of North America, as well as in the waters of nearby islands (Cuba, the Bahamas and others).

Facts about the life of white sharks

A whole sea lion, weighing 45 kilograms, was once found in the stomach of a white shark.

About the life of white sharks

Due to frequent attacks on swimmers in Australia, the great white shark is called the “white death”.

About white sharks

The great white shark lives at depths of up to 30 meters.

Interesting facts about white sharks

The color of the white shark's back is not white, but gray or lead-gray, its belly is dirty white, and the fin on its back is black. Only large individuals are painted completely lead-white.

Facts about white sharks

Young white sharks prey on small fish, dolphins and turtles. Growing up to 3 meters in length, sharks turn their attention to large fish and marine mammals.

Unknown facts about the life of white sharks

The white shark prefers to take its prey by surprise.

34 facts about the life of white sharks

When attacking, a white shark opens its toothy mouth wide and snatches a piece of meat from the victim. If it suits the taste, then the shark waits until the victim bleeds out and calmly eats it. If the food is not suitable, then the great white shark abandons the prey after the first bite.

About white sharks

Having identified the prey, the white shark slowly swims in circles around the prey.

Interesting facts about the great white shark

The upper jaw of a great white shark is lined with blade-like, sharp, cone-shaped teeth, and the lower jaw is lined with needle-thin teeth. It is with the help of the lower teeth that the white shark holds the victim with a death grip.

What do you associate with the word “shark”? One of the most terrible and dangerous predators for humans living in the depths of the sea?

We present to your attention a selection interesting facts about sharks, thanks to which you will learn a lot of new things about these unusual creatures.

1. Not all sharks are dangerous to humans.

Most people believe that sharks are giant man-eaters, but this is far from true. There are 440 species of sharks known in nature, but only 12 of them are truly dangerous to humans. The sizes of sharks vary greatly from 12 meters to 20 centimeters. The largest shark in the world is considered to be the whale shark. It lives in almost all tropical waters of the world. The diet of the largest shark in the world consists exclusively of crustacean plankton.

2. The smallest shark in the world is the dwarf lantern shark.

Like the whale shark, the pygmy shark is found in almost all tropical waters.

3. All known species of sharks lack a bony skeleton.

The outstanding strength and flexibility of sharks is due to the fact that their skeleton consists of cartilage, but this same fact makes them very vulnerable.

4. All sharks have prominent teeth.

If a shark suddenly loses a tooth, literally in two weeks a new one will grow in place of the old tooth, and this can continue until the shark dies. It is worth noting that not all types of sharks have super sharp teeth. The shape and size of a shark's teeth directly depends on what it eats. For example, a shark that feeds on shellfish has large, flat teeth; This type of teeth allows the shark to easily get rid of mollusk shells. The already known whale shark, which feeds on krill (crustacean plankton), has small and thin teeth.

5. Sharks can smell prey from several thousand meters away.

In addition to the fact that sharks are endowed with an excellent sense of smell, their heads also contain the so-called ampullae of Lorenzini - a sensory organ that allows them to detect the slightest changes in temperature, pressure and electric field. Having poorly developed vision, even in muddy water, a shark can easily hit its prey.