White shark. Great white shark: photo and description White shark where

The second article from the series "Summer with sharks" tells about the famous representative of the giant marine predators- a great white shark, memorable to many based on the film"Jaws". Is this huge fish as dangerous and bloodthirsty as is commonly believed?

Meeting with a great white shark in the ocean is somehow not like what the imagination draws: the fish does not at all look like a bloodthirsty monster, about which thousands of television programs talk about with chilling intonations in their voice. She is very plump - like a fat sausage - with her mouth, as if parted in a self-satisfied grin, with shaking flabby wings. In a word, when viewed from the side, one of the most dangerous predators the planet resembles a gaping clown. And only when the "clown" turns to face you, so to speak, do you understand why this predator causes such fear - and they are afraid of him almost more than any other animal on the planet. The shark's muzzle no longer seems flabby - it narrows into an ominous battering ram with black unblinking eyes. The smirk disappears and all you see is rows of five-centimeter teeth protruding from the jaws (when they bite, they create a pressure force of 1800 kilograms per square centimeter). The shark is slowly but surely approaching you. Turns his head - first in one direction, then in the other, assessing whether the prey, that is, you, is worthy of wasting time on it. Then, if you are lucky, she will turn around, turn into a clown again, and lazily disappear into the underwater darkness. More than 500 species of sharks live in the oceans, but in the minds of the vast majority of people, there is only one. When Pixar needed a villain for Finding Nemo, they didn’t choose a harmless nurse shark or an aggressive blunt shark, or even a tiger shark, which would have looked more appropriate on the coral reef where Nemo lives. No, from thousands of posters around the world, it was the big one that grinned White shark. This fish is a symbol of the oceans, but our knowledge about it is very scarce - and much of what we seem to know is simply not true. White sharks are not blood-blind killers (on the contrary, they act cautiously when attacking the victim), they do not always live alone and are probably smarter than scientists believed until recently. Even the famous series of attacks on people off the coast of New Jersey in 1916, mentioned in the movie "Jaws", may be the tricks of a blunt, not a great white shark. We do not know for sure what the duration of her life is, how many months she bears offspring when she reaches puberty. No one has ever seen great white sharks mate. or produce offspring. We do not really know how many there are and where they spend most of their lives. If in California South Africa or Australia, a predator the size of a small truck lived on land, experts would observe representatives of this species in zoos or research centers and in all details would study his mating behavior, migration routes, habits. But underwater have their own laws. White sharks appear and disappear at will and follow them in sea ​​depths almost impossible. They do not want to live in aquariums - some refuse to eat and die of hunger, others attack all neighbors and smash their heads against the walls. However, scientists who use modern technologies, may already come close to answering two of the most exciting questions: how many great white sharks are and where they hide. This is necessary to know in order to decide how to protect ourselves from white sharks and how to protect them from us, and to understand what the most terrible predator on the planet deserves more - fear or pity.

Brian Skerry A great white shark rips up the water surface near the Neptune Islands. Scientists distinguish sharks by their dorsal fins, scars, and a jagged line separating the white ventral and gray dorsal parts of the body.

A seven-meter fishing boat bobs in the waves off the southern tip of Cape Cod, Massachusetts. It's a beautiful summer day. The passengers—three scientists, two paid tourists, a couple of journalists, and the captain—were comfortably seated, looking out toward Nantucket Island. Suddenly, the walkie-talkie comes to life, and the voice of the pilot-observer from a height of 300 meters says in a sharp New England accent: “There is a great shark to the south of you!”. Marine biologist Greg Skomal perks up. He stands on a bridge fenced with railings, which protrudes one and a half meters ahead of the bow of the boat and looks like a plank along which pirates pushed those sentenced to death into the sea. If we were in a Hollywood movie, Greg would have a wooden leg and a harpoon in his hands. But instead of a harpoon, Greg is holding a three-meter pole, at the end of which is a GoPro camera. And beams with joy when the captain starts the engine. Until 2004, almost no one saw great white sharks off the East Coast of the United States. From time to time, individual individuals appeared near the beaches or fell into the nets, but this happened very infrequently. In general, white sharks gather at certain times of the year in five areas that scientists call "hubs", by analogy with hub airports. The three main hubs are off the coast of California and Baja California, southern South Africa and Australia, where these predators prey on seals. However, the East Coast is not the right place: there are not enough seals here. The sharks that swam here were homeless vagrants. In 2004, one female made her way into the bays near the village of Woods Hole, Massachusetts. For Skomal, who by that time had been successfully marking other types of sharks with electronic beacons for twenty years, this was a rare chance: a big white appeared, one might say, right in his yard! “I thought it was an accident that will never happen again,” he says, a smile playing across his face framed by tousled gray hair. Over the next two weeks, Skomal and his colleagues followed the shark, which they named Gretel, after the lost girl from the Brothers Grimm's fairy tale, and eventually provided her with a beacon. Scientists hoped to track the movement of the shark in the Atlantic Ocean, but after 45 minutes Gretel's beacon fell off. “My excitement turned to deep despondency, because I was sure that I had missed the only chance in my life to learn something new about the great white shark,” recalls Skomal. Over the next few years, he thought a lot about Gretel and whether she really was a loner. But in September 2009, everything, fortunately, cleared up: five great white sharks were spotted from an airplane near the cape. Within a week, Skomal had tagged them all. “I almost went crazy with joy. Her heart was beating so hard it was ready to jump out of her chest. Everything I dreamed of came true! says Greg. Since then, great white sharks have returned every summer. Some scholars have even named Cape Cod as the sixth hub. How many sharks are there? To answer this question, let's turn to the data on the California hub. The first attempt to count sharks here was made in the mid-1980s by Scot Anderson, who at the time was studying seabirds on an island west of the Golden Gate Bridge in San Francisco. Anderson and his colleagues tracked the sharks, first visually, then with acoustic beacons, and finally with satellites. Over the past 30 years, they have processed data from thousands of observations of individual sharks, which were distinguished by the shape of the dorsal fins, markings on the skin, or by the characteristic border between the gray back and white belly. Now we know where these sharks gather and what they eat (most of the "observations" returned here year after year). So is it possible, based on such observations, to determine the number of sharks? In 2011, a group of scientists tried to make such a calculation, and it turned out that only 219 adults live in the richest shark area in California. Even taking into account the fact that the number of predators at the top of the food pyramid is usually much smaller than the number of animals they prey on, this is still negligible. The results of the study stunned the public and were immediately criticized by other specialists.

Brian Skerry Biologist Greg Skomal tries to make a video of a shark swimming near Cape Cod. Recently, great white sharks have begun to regularly appear in the waters off the popular beach.

Of course, counting the number of great white sharks is much more difficult. than land animals or even marine mammals. Therefore, scientists draw conclusions based on their assumptions about the ways of movement of sharks. In the case of the California coast, the most important assumption was that the data on several feeding sites were extended to the entire hub. Another group of scientists processed the same data using different assumptions, and they found the number of sharks to be ten times greater (although they also counted juveniles). Soon, ichthyologists began to count sharks in other hubs. Let's say the population of South African sharks was estimated at 900 individuals. How big or small are these numbers? Are great white sharks thriving or dying out? There are about 4,000 tigers and 25,000 African lions in the world. Based on the lowest estimates, there are as many great white sharks on the planet as tigers, and they are known to be a threatened species. If we take the highest ratings, then these fish are no less than lions - a vulnerable species. Some experts believe that sharks are dying out, others, on the contrary, see positive changes. Some say that the increase in the number of seals indicates that there are almost no great white sharks left, others argue that the more seals, the more sharks should be. For example, Australian statistician Aaron McNeil believes that the appearance of sharks off the Cape Cod Peninsula and the increased number of sightings in the Southern Hemisphere support an optimistic view. "Per last decade I don't see any evidence that there are fewer sharks,” McNeil says. – In the past there was a period of decline in numbers, but today it cannot be said that great white sharks are dying out. Perhaps their numbers are growing very slowly, but growing.” Hope remains. Today, if anyone catches great white sharks purposefully, there are very few such fishermen - however, in the Convention on International Trade in Threatened Species, this species is listed in the second category of the severity of protection, since it happens that fishermen catch these fish unintentionally. After all, if the number of the species is small, even an accidental catch can deal a crushing blow to its populations - and the great white shark, being a top predator, plays a crucial role in the ecology of the oceans. To see if great white sharks need our protection, it is necessary to know not only their number, but also where they wander. Their migration paths are not as ordered as, say, birds or butterflies. Some sharks follow along the coast, others tack hundreds of kilometers into the open sea. Many white sharks change depending on the time of year. warm waters to cold and vice versa. And it looks like males, females, and juveniles follow different paths. Today, with long-term satellite beacons, scientists are finally beginning to understand these intricacies. We now know that adult white sharks from California and Mexico leave the coastal zone in late autumn and go to the depths in the middle Pacific Ocean. “It’s not at all clear why they go to this area, which some call an oceanic desert,” says Salvador Jorgensen, a biologist who studies the migration and ecology of great white sharks. “What the hell are they doing there?” Isn't this "shark center" where great white sharks mate like no one has ever seen? The water area in question is the size of California, and the depths there reach kilometers, and it is difficult to watch sharks. However, satellite beacon data shows that the females are following direct routes, while the males are surfacing and diving, probably in search of mates.

This is how the idea of ​​the life of the great white sharks of the California coast is gradually formed. After spending the summer and autumn hunting seals, they head to ocean depths to start breeding. They live at this time due to the accumulated fat reserves. Then the males return to the coast, and the females swim off somewhere for a year or so, perhaps to give birth to offspring. The young are later shown to feeding grounds (eg off the coast of Southern California) where they feed on fish before they grow large enough to join the older tribesmen. The picture drawn is not complete - males and females do not spend much time together, and we do not know where the cubs are born - but it explains a lot. For example, as the population recovers, more young appear, which may be why there have been so many sharks in Southern California lately. In other places, the calculations are more difficult. Australian sharks feed off the southern coast of the mainland, but they do not seem to have their own "center". As for the Atlantic, here our knowledge is even poorer. “We have 'tramps' and we have coastal sharks. And I have no idea what drives both of them,” says Greg Skomal. On a clear August morning, I board a two-seat plane with Wayne Davis, a pilot who has been tracking tuna and swordfish for fishermen for many years and is now helping scientists find great white sharks. It is so shallow here that sharks can be seen from the air. In just half an hour of flight, we see seven - they all patrol parts of the coast, next to which gray seals feed. On the way back, a mile to the north, we fly over beaches crowded with vacationers. Bye locals welcome new neighbors. Shops sell toy sharks, T-shirts and posters with their image, even the new mascot of the local high school- great white shark. Sharks, as a rule, are depicted in profile - smiling, similar to clowns. But sooner or later, someone will meet in the local waters another version of the great white shark - the one with teeth. However, these predators rarely encroach on people's lives. In California, the chance of a surfer being bitten by a great white shark is one in 17 million, according to Stanford University, and even less for people just swimming in the water, at one in 738 million vacationers. Will we be able to lend a helping hand to this toothy monster, are we ready to pity the ruthless monster?

Since ancient times, a person has a keen desire to see all the very best - for example, a photo that depicts the largest white shark. But such a picture is extremely difficult to take.

There are many reasons. Among them are the difficulties of detecting a particularly large predator, choosing the optimal angle, insufficient visibility in ocean water, and the danger that accompanies contact with a shark.

Unlike marine animals, known for their curiosity and contact, she will consider an object unknown to her from the point of view of its edibility / inedibility.

Some individuals of great white sharks still grow to sizes unattainable by another marine predator, the killer whale (Orcinus orca). Killer whales reach a maximum length of 10 meters and a 7-ton weight (they are more "fat"); The maximum length of white sharks has not been precisely established.

Who is the great white shark?

Sizes of the largest white sharks

The exact lifespan of great white sharks is unknown - they fail long time and watch them.

Scientists believe greatest age white sharks equal to 70-100 years. If the maximum lifespan of predators is really equal to a century, then the size of a 100-year-old shark should be simply huge and figures of 10-12 meters will not be at all limiting.

The original photos, where the largest white shark lies dead weight at the feet of fishermen, are dated 1945: the caught shark weighed about 3 tons, its length is 6.4 meters.

True, there is one point here - the bodies of sharks caught and removed from the water quickly lose moisture, i.e. shrivel, decreasing in size and weight. Therefore, the results of measurements taken immediately after the capture of the predator and after some time do not match - the difference can be up to 10%.

Photo: The biggest white shark

For a person, this is just a loss or gain of profit; for marine life, this is a real threat of extinction in any case.

The great white shark can reach large sizes with age and only under favorable conditions: an abundance of food, the absence of enemies and favorable water temperatures. But these opportunities are becoming less and less every year ...

intermediate ranks

Carcharodon carcharias Linnaeus,

Systematics and origin

In the evolutionary relationships of the white shark and other modern and extinct species herring sharks much remains unclear. The ancestor of this group was probably Isurolamna inflata, which lived about 65 - 55 million years ago and had small narrow teeth with a smooth edge and two lateral teeth. This family shows a trend towards an increase, broadening and serration of teeth in the course of evolution (transition from a grasping function to cutting and tearing), which led to the characteristic appearance of the teeth of the modern white shark.

Distribution and habitats

area

The white shark lives throughout the ocean, preferring areas of temperate coastline, continental and insular shelves, usually closer to the surface of the water. Some large specimens also appear in tropical waters. It also sometimes makes spontaneous movements to the area of ​​​​cold seas - the species has been recorded off the coast of Canada and Alaska. Large individuals are able to regularly carry out long ocean journeys. It can also be found at a decent depth - there was a case of catching a white shark at 1280 meters with bottom fishing gear along with a sixgill shark. Observations show that at least large individuals tolerate a fairly wide range of environmental temperatures - from cold seas and the ocean floor to the coast of the tropics. At the same time, individuals of smaller sizes (less than 3 m) are more common in temperate latitudes.

Habitats

The main centers of congestion of the white shark are coastal waters American California and Mexican Baja California, Australia and New Zealand, the Republic of South Africa and, once, the Mediterranean. It can be found in the East Coast of the United States, off the coast of Cuba, the Bahamas, Argentina, Brazil; in the Eastern Atlantic - from France to South Africa; in the Indian Ocean appears in the Red Sea, off the coast of the Seychelles, as well as off the Reunion Island and in the waters of Mauritius; in the Pacific Ocean - from the Far East to New Zealand and the western coast of America.

Migrations

Anatomy and appearance

The white shark has a strong, large, conical head. The width in the upper lobe and in the lower lobe (near the tail) is the same (as in most herring sharks). The white shark has a protective coloration: it is white in the lower part and gray in the back (sometimes with a brown or blue tint), which gives the impression of a mottled coloration, which makes it difficult to detect the shark, since its body visually disintegrates when viewed from the side. When viewed from above, the dark shadow dissolves into the thickness of the sea, and when viewed from below, the silhouette of a shark is hardly noticeable against the background of light. White sharks, like many others, have three rows of teeth. The teeth are serrated, and when the shark bites and shakes its head from side to side, the teeth cut like a saw and tear off pieces of flesh.

Dimensions

The size of a typical adult white shark is 5-6 meters with a mass of 600-3000 kg. Females are usually larger than males. The maximum size of the white shark is a hotly debated topic. Richard Ellis and John E. McCosker, recognized scientific experts on sharks, devoted an entire chapter to this subject in their book The Great White Shark (1991), which analyzes various reported maximum sizes.

For several decades, many works on ichthyology, as well as the Book of Records, cited the largest of two specimens: a 6.9 m long shark, caught in southern Australian waters near Port Fairy in the 1870s, and a 7.3 m long shark, caught in a herring trap at a dam in New Brunswick, Canada in 1930. Reports of specimens being caught as long as 7.5 meters were common, but the above measurements remained record-breaking.

Some researchers question the reliability of the measurements in both cases, as these results were significantly larger than any other results obtained by accurate measurements. The New Brunswick shark may not have been a white shark, but a giant shark, since both sharks have a similar body shape. The question of the size of the Port Fairy shark was clarified in the 1970s when Gee. I. Reynolds studied the shark's mouth and found that the Port Fairy shark was about 5 meters in length. He suggested that in 1870 an error had been made in the original measurement.

Ellis and McCosker determined the size of the largest specimen, the length of which was reliably measured, at 6.4 meters, which was caught in Cuban waters in 1945. However, in this case, there are experts who claim that the shark was actually several feet shorter. The unconfirmed weight of this Cuban shark is 3270 kg.

Food

Young sharks feed on small fish, tuna. Grown up sharks switch to feeding on seals, do not bypass the carcasses of dead whales. Their light coloration makes them less visible against underwater rocks when they are stalking prey. Their high body temperature makes them faster and smarter than most sharks, which is essential when hunting seals. Fatty foods are needed to maintain a high temperature. The blood vessels that carry blood to the skin transfer heat to the blood vessels that carry blood in the opposite direction to reduce heat loss. The white shark first attacks horizontally on seals, like fish, but then changes its habit and attacks from below, so that the prey does not notice it until the last. Sometimes a shark takes people for seals and attacks, but, feeling bones in its teeth instead of seal fat, lets go. And since these predators usually swim in a flock, there can be several bites. When attacking, it rolls its eyes to protect them from the claws of victims.

reproduction

Notes

1. Reshetnikov Yu. S., Kotlyar A. N., Rass T. S., Shatunovsky M. I. Five-language dictionary of animal names. Fish. Latin, Russian, English, German, French. / under the general editorship of acad. V. E. Sokolova. - M .: Rus. yaz., 1989. - S. 23. - 12,500 copies. - ISBN 5-200-00237-0
2. Great White Sharks now more endangered than tigers with just 3,500 left in the oceans | mail online
3. Carol Martins & Craig Knickle WHITE SHARK (English) . Education. Florida Museum of Natural History. Archived from the original on February 27, 2012. Retrieved October 8, 2011.
4. Jim Bourdon Carcharodon (English) . The Life and Times of Long Dead Sharks(2009). Archived from the original on June 5, 2012. Retrieved May 12, 2012.
5. R. Aidan Martin Fossil History of the White Shark. ReefQuest Center for Shark Research. Archived from the original on February 27, 2012. Retrieved October 10, 2011.
6. Compagno L.J.V. Part 2 - Carcharhiniformes // Sharks of the world. An annotated and illustrated catalog of shark species known to date / Pere Oliver. - Rome: FAO, 2001. - Vol. 2. Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). - P. 100-107. - $269 - (FAO Species Catalog for Fishery Purposes). - ISBN 92-5-104543-7
7. Ramon Bonfil; Michael Meÿer, Michael C. Scholl, Ryan Johnson, Shannon O'Brien, Herman Oosthuizen, Stephan Swanson, Deon Kotze and Michael Paterson2 Transoceanic Migration, Spatial Dynamics, and Population Linkages of White Sharks. science magazine. AAAS (October 7, 2005).

A well-known representative of predatory fish is the great white shark. Individuals belonging to Carcharodon carcharias live in the surface layers of the water column of various oceans, although they are also found at depth. Only in the Arctic Ocean there are no sharks. These predatory fish are called white death, cannibal fish and carcharodons (terrible teeth).

White shark characteristics: size, weight, tooth structure

White sharks owe their name to their specific appearance. AT White color the peritoneum of predatory fish is colored, their sides and back are gray, in some individuals it is gray-blue or gray-brown.

Due to the specific color, it is difficult to notice the fish from afar. gray color back and sides does not allow to see them from above, they merge with the surface of the water. If you look up from the bottom of the ocean, then the white belly does not stand out against the sky. The body of a shark is visually divided into 2 parts when viewed from the side from afar.

The female sharks are larger than the males. The average length of female carcharodons is 4.7 m, and males grow up to 3.7 m. With such a length, their body weight varies between 0.7–1.1 tons. According to experts, man-eating fish that are in ideal conditions, can grow up to 6.8 m. The body of the white shark is spindle-shaped, dense. There are 5 pairs of gill slits on the sides. On a large conical head are medium-sized eyes and nostrils.

Due to the grooves that fit the nostrils, the volume of water entering the olfactory receptors increases

The mouth of a predatory fish is wide, it has the shape of an arc. Inside there are 5 rows of triangular sharp teeth, their height reaches 5 cm. The number of teeth is 280–300. In young individuals, the first dentition is completely changed every 3 months, in adults - every 8 months. A feature of carcharodons is the presence of notches on the surface of the teeth.

Powerful shark jaws are able to easily bite through the cartilage, break the bones of their victims. With the help of a study conducted in 2007, it was possible to find out the bite force of this predator.

Computed tomography of the head of the shark helped to establish that the bite force of a young individual weighing 240 kg and 2.5 m long is 3131 N. And a shark 6.4 m long and weighing more than 3 tons can close its jaws with a force of 18216 N. According to the assumption of some scientists, information about the bite force of large sharks is overestimated. Due to the special structure of the teeth, sharks do not need to be able to bite with great force.

The first large fin on the back looks like a triangle, pectoral fins have a crescent shape, they are long, large. The anal and second dorsal fins are small. The body ends with a large tail, its plates are the same in size.

In large carcharodons, the circulatory system is well developed. This allows predators to warm up their muscles and increase their speed in the water. swim bladder white sharks do not. Because of this, Carcharodons are forced to constantly move, otherwise they sink to the bottom.

Where does it live

The habitat of man-eating sharks is huge. They are found both in coastal areas and inland. Mostly sharks swim in surface waters, but some specimens could be found at a depth of more than 1 km. They prefer warm waters optimum temperature for them it will be 12-24 ° C. Sharks are not suitable for desalinated and low-salt waters.

Carcharodons are not found in the Black Sea

The main centers of accumulation of predators include coastal zones in California, Australia, South Africa, and New Zealand. Sharks are also found:

• off the coast of Argentina, the Republic of Cuba, the Bahamas, Brazil, the east coast of the United States;
• in the east of the Atlantic Ocean (from South Africa to France);
• in Indian Ocean(found near the Seychelles, in the Red Sea and the waters of the Republic of Mauritius);
• in the Pacific Ocean (along the western coast of America, from New Zealand to the Far Eastern territories).

Often sharks can be seen around archipelagos, shoals, rocky capes inhabited by pinnipeds. Separate populations live in the Adriatic and Mediterranean seas. But their number in these water bodies has significantly decreased in recent years, they have practically disappeared.

Lifestyle

people social structure shark populations and the behavior of individual individuals have not been studied enough. With the help of observations, it was possible to reveal that the tactics of attack by predators depend on the type of prey chosen. This contributes heat body, which stimulates the functioning of the brain.

Their attacks are so swift that in pursuit of prey they can completely emerge from the water. At the same time, animals develop speeds above 40 km / h. A failed attack does not stop the pursuit of the victim. They can raise their heads above the water while searching for prey.

Interspecific competition occurs in places where sharks and cetaceans have a single food base.

It was previously thought that white sharks had no natural enemies. But in 1997, whale watching had to witness an attack on an adult white shark. It was attacked by a representative of cetaceans - a killer whale. Similar attacks were recorded later.

Nutrition and the digestive system

The diet of carcharodons varies depending on the age and size of the animals. They feed on small animals.

• fish (tuna, rays, herring and small representatives of the shark family are popular);
• pinnipeds (fur seals, lions, seals most often suffer);
• cephalopods;
• birds;
• representatives of whales ( porpoises, dolphins);
• sea ​​otters, turtles.

Carcharodons do not neglect carrion. Whale carcass can be good prey.

Of particular interest to large specimens are seals, other marine animals, and small whales. With the help of fatty foods, they manage to maintain energy balance, so they require high-calorie foods.

But they rarely attack porpoises and dolphins. Although in the Mediterranean the latter are an important component of the diet of sharks. They attack this type of prey mainly from below, behind and from above, trying to avoid detection by sonar.

Contrary to popular belief, sharks are not interested in humans as food due to the small amount of fat. Carcharodons can confuse a person with marine mammals which is believed to be the main cause of the attack.

White sharks have a slow metabolism, so sometimes they can go without food for a long time.

Predators can go without food for a long time. It is believed that 30 kg of whale oil is enough to satisfy the metabolic processes taking place in the body of a shark weighing more than 900 kg for 45 days.

According to the structure of the digestive organs, sharks practically do not differ from other fish. But in carcharodons, the division of the digestive system into various sections and glands is expressed. It begins with the oral cavity, which smoothly passes into the pharynx. It is followed by a V-shaped esophagus and stomach. The folds inside the stomach are covered with a mucous membrane, from which digestive enzymes and juices are abundantly secreted, necessary for the processing of ingested food.

In the stomach there is a special section in which excess food is sent. Food can be stored in it for up to 2 weeks. If necessary, the digestive system begins to use the available supply to support the life of the predator.

From other species of fish and animals, sharks are distinguished by the ability to “turn out” the stomach through the mouth. Thanks to this ability, they can clean it of dirt, accumulated food debris.

From the stomach, food passes into the intestines. The existing spiral valve contributes to more efficient absorption. Due to its presence, the contact of food digested in the stomach with the intestinal mucosa is enhanced.

Also active in the process of digestion are:

• gallbladder;
• pancreas;
• liver.

The pancreas is responsible for the production of hormones, pancreatic juice, designed to break down carbohydrates, fats, proteins. Thanks to the work of the liver, toxins are neutralized, pathogenic microorganisms are destroyed, and fats from food are processed and absorbed.

Behavioral features

White sharks do not live in one place. They move along the coast, make transatlantic journeys, but return to their usual habitats. Due to migrations, there is the possibility of crossing different shark populations, although they were previously thought to live in isolation. The reasons for the Carcharodon migrations are still unknown. Researchers speculate that this is due to breeding or searching for places rich in food.

During observations in the waters of South Africa, it was revealed that the dominant position is assigned to females. When hunting, predators are divided. Arising conflicts are resolved with the help of demonstrative behavior.

White sharks start a fight in exceptional cases

Their behavior during hunting is interesting. The whole process of catching a victim can be divided into stages:

1. Identification.
2. Species identification.
3. Approaching an object.
4. Attack.
5. Eating.

They attack mainly when the prey is near the surface of the water. They grab large individuals in the middle and drag them under water. There they can swallow the prey whole.

Diseases

The threat to Carcharodons is small crustaceans copepods. They settle in the gills, feed on the shark's blood and the oxygen that it receives. Gradually, the condition of the gill tissue worsens and the shark dies from suffocation.

Predators are known for their well-functioning immune system, which is able to protect them from autoimmune, inflammatory and infectious diseases but they often get cancer. Now it was possible to identify more than 20 types of tumors that threaten the life of sharks.

Reproduction: how white sharks give birth

Young sharks are born adapted to independent living.

White sharks are ovoviviparous fish. Fry hatch from eggs inside the mother's body. They come out grown up. Communication with the mother's body is absent. The species reproduces by placental ovoviviparity. There are 2–10 sharks in a litter. Most often, 5-10 newborns are born. Their length at birth is 1.3–1.5 m.

The source of nutrients for growing embryos are eggs, which are produced by the mother's body. The sharks in the womb have a stretched belly 1 m long, inside it is the yolk. For more late stages stomachs become empty. Newborn sharks are most often seen by observers in calm waters. They are well developed.

How many lives

The average lifespan of Carcharodons is 70 years. At the same time, puberty in females occurs at the age of 33, in males - at the age of 26. They stop growing from the moment they reach maturity.

attack on a person

People are not of interest to sharks, although many cases have been recorded when they attacked. Most often, divers and fishermen who come too close to the predator become victims.

in the waters mediterranean sea there is a "shark phenomenon", according to which Carcharodons swam away after one bite. According to experts, sharks that are hungry can easily profit from a person.

Most often, when meeting with sharks, people die from blood loss, drowning, or pain shock. When attacking, predators injure prey and wait for it to weaken.

pretend to be dead - worst case in a collision with a shark

Single divers can be partially eaten by a shark, and people who dive with partners can be saved. Often it is possible to escape those people who actively resist. Any blows can force the predator to swim away. Experts advise, if possible, to beat the shark in the eyes, gills, muzzle.

It is important to constantly monitor the location of the predator, it can attack again. Sharks are willing to eat carrion, so the sight of an unresisting prey will not stop them.

Sharks are a little-studied species of predatory fish. A decrease in their numbers affects the food chain, because they are part of the ecosystem of the world's oceans. Despite the fact that little is known about white sharks, researchers have been able to identify a number of interesting facts related to these animals:

• Females have thicker skin than males. This is due to the fact that the male roughly holds his partner during mating, biting her by the fins.
• Shark teeth are coated with fluoride, so they do not deteriorate. Enamel is made up of a substance that is resistant to acid produced by bacteria.
• Sharks have well developed: vision, smell, hearing, touch, taste and sensitivity to electromagnetic fields.
• Sensitive olfactory receptors enable the shark to catch the smell of a seal colony located at a distance of 3 km.
• When hunting in cold waters, Carcharodons are able to raise their body temperature.

Due to industrial fishing, the number of white sharks is rapidly declining. According to experts, there are about 3.5 thousand of them left all over the world. If sharks begin to die out, this could lead to the extinction of many marine plants.

Of all possible marine predators, the great white shark has generated a huge amount of speculation and gossip. By the way, about half of them are nothing more than fantasies of frightened people. But the shark does not give up. Throughout the entire time of its existence, it confirmed its title of super-predator.

Classification

The great white shark was first classified by Carl Linnaeus in 1758. He identified it as Squalus carcharias. However, this classification did not take root. Already in 1833, another scientist - Smith - identified the shark as Charcharodon. This generic name comes from Greek word charcharos (sharp) and odous (tooth).

The great white shark received its final classification in 1873. The international scientific name for the shark is Charcharodon carcharias. As you can see, it appeared as a result of combining the names given by both Linnaeus and Smith.

Spreading

Most divers would like to know where the great white shark is found. Some are interested in this question, because they want to avoid meeting with the largest predatory fish in the world at all costs. Others, on the contrary, dream of swimming with the Carcharodon at least once. Forced to disappoint the first and please the second: the predator lives in all the oceans of the planet. The only exceptions are the cold waters of the Arctic Ocean.

But the great white shark prefers tropical and temperate seas, living in the open sea around the continental shelf. The ideal temperature for life and reproduction of sharks is 12-24 °C. Great importance for it also has a salinity level of water. So, in seas with low-salt water, it is impossible to meet a predator. This explains, for example, the fact that the shark does not swim in the Black Sea, although in the neighboring Mediterranean, there are more than enough of these predatory fish. It is also found in the Adriatic Sea, as well as around the northern coast of Spain. Despite their dislike for cold water, in the Atlantic Ocean, the predator was seen even off the coast of Nova Scotia. As for the Pacific Ocean, the shark even swims to the coast of Australia. It must be clarified that the predator does not lead a sedentary lifestyle. It is in constant motion and migrates from one coast to another, the distance between which can reach a thousand kilometers.

Appearance

Of the more than 400 species of these predatory fish, the great white shark is the most equipped. The physical data of Carcharodon are impressive. She has well-developed vision, hearing, smell, taste and tactile sensations, and even electromagnetism. Its body is fusiform with a gray or lead gray back and a white belly. Such colors are the natural camouflage needed by the predator in order to blend in with the environment during an ambush. It must be said that what bigger size reaches an individual, the lighter its color. The color of some may be completely lead-gray.

The white shark is able to determine the level of salinity of the water, as well as its chemical composition and feel their changes. This is possible due to special receptors that are located on the head, back and along the sides of the fish.

Carcharodon's sense of smell is quite high. This is facilitated by small grooves around the nostrils of the predator. It is they who increase the speed with which water flows into the nostrils.

The speed and mobility of the predator is provided a high degree development of the circulatory system. Such natural data helps the shark to quickly warm up the muscles. This is especially important, given that it must be in constant motion. Otherwise, she would have drowned, because the predator does not have a swim bladder.

The size of the great white shark is impressive. It reaches 4-5 meters in length. The maximum size of a shark, which scientists call, is 8 meters. It is this figure that is accepted among most ichthyologists. However, some of them are sure that the shark can even reach 12 meters in length. A photo of the largest white shark that a person has ever seen is provided below. Its length was 11.2 meters.

The average weight of a great white shark is one ton. However, this is not the limit. The record weight is considered to be 3.5 tons. But the largest weight among sharks caught by man was a predator caught more than half a century ago off the coast of Australia (1208.3 kg).

The life expectancy of a great white shark is negligible, given its physical characteristics: only 27 years.

Jaws

One of the most amazing systems in a shark's body is its jaws. They are the best suited to kill. At one time, the shark tears off a piece of meat, the weight of which can be 30 kilograms.

The animal has several jaws. Their number may vary depending on the age and lifestyle of the predator. The giant great white shark can even have seven rows of teeth. Although there are individuals whose jaws have only three rows.

The first, outer jaw has about 50 teeth. The lower one serves to hold the victim in place and prevent her from leaving. The front teeth of the upper jaw act as knives, with which the predator can cut off huge pieces of meat. Her kick reaches a force of 318 kg.

In order to fully understand why the shark needs the second, third or fourth rows of teeth, you would probably have to look under the skin of the predator. There are more than a hundred such teeth, and they are freely located under the skull. To expose the gums and teeth when biting, special grooves and muscles in the skull work. While the lower jaw rises to clamp the next victim, its target increases. A massive blow of the upper jaw completes what has been started. Hunting in this way, the shark is able to eat more than 180 kilograms of meat. And that's just one time! Given that catching prey is sometimes not so easy, the shark has constantly improved its mechanisms for killing. And she had enough time for this - more than a million years.

organs of vision

Eyes are another mechanism created for hunting. But you have to do this in a poorly lit environment. However, the organs of vision are also the most vulnerable spot, which has a great white shark on its body. Photos taken by many amateurs and scientists confirm that the predator has to stick its head out of the water in order to better see the world. No other fish in the world is capable of this.

Shark eyes have a special reflective layer behind the retina. This allows you to hunt even when there is not enough light. It is mirrored in the eyes of the shark, and it is able to see its prey even in dark water. But the sensitivity of the eyes has its drawbacks. During the attack, they are quite easy to damage. Probably, the shark could not have survived for millions of years if nature had not taken care of this predator and given it ideal remedy protection. Once the Carcharodon is ready for its famous deadly bite, his eyes roll inward.

Intelligence

To operate this killing machine, you need a really developed intellect. After all, she must not only successfully hunt in order to survive, but also make long journeys. To decipher the signals of all the senses (and there are six of them in a shark), the level of brain development must be at a sufficient level. high level. In Carcharodon, the brain occupies the entire cranium. Like all other organs of a shark, it was formed over millions of years.

reproduction

The white shark belongs to the ovoviviparous type of fish. In fact, it is not known how the mating of individuals and the birth of cubs occurs, since none of the people was an eyewitness to this. However, it is safe to say that the female bears cubs for about 11 months. In addition, cannibalism is developed among these unborn babies. Scientists call it intrauterine. Nature has established that strong offspring destroy the weak even in the womb. The female can only give birth to one or two cubs, however, you can be sure that they have become the strongest among their brothers and sisters. Naturally, babies are born immediately with teeth. They also cover most of their bodies. Thus, the young survive in the harsh underwater world.

Menu

By nature, the white shark is very aggressive. She is capable of attacking any victim within reach. However, its main diet is fur seals, seals, bony fish and slopes. In addition, the white shark shamelessly kills its relatives - sharks of other species that are inferior to it in body size.

The young begin to hunt immediately after birth. However, they can only do small fish, dolphins and turtles. After the young shark reaches the size three meters, she is able to cope with prey, the body size of which is two-thirds of her own.

Cases of attack on a person

It is worth saying that people are not the main and not the most favorite component of the menu of the great white shark. Cases when a shark attacked a person occur mainly due to the fault or negligence of the latter. Some enthusiasts forget that swimming up to a predator is deadly. Undoubtedly, there are cases when a shark attack is not provoked by anything. The reason for this may be severe hunger as a result of an unsuccessful previous hunt. Some white shark populations, such as the Mediterranean shark, are surprisingly friendly towards humans.

Security

The white shark is at the top of the food chain, so natural enemies she has practically none. The only exception is a large killer whale, and of course, a person. Today the shark is in a vulnerable position. Hollywood directors, without knowing it, did a disservice to the predator. After the release of the film "Jaws", it was the great white shark that was under threat. A photo of a predator is not the only trophy that adventurers want to get. Shark jaws are very popular and are sold at an impressive price on the black market.

Due to the fact that the population of this predator is declining every year, in many countries it has been taken under protection. Among them are Australia, USA, South Africa.