Where is the whale shark found? Whale shark

Whale shark (lat. Rhincodon typus)- the largest species of shark, as well as the largest living representative of fish. Although, according to some eyewitnesses, they encountered specimens ranging from 18 to 20 m in length, the largest specimen ever measured was 13.7 m in length. The weight of whale sharks can reach 12 tons. Despite its impressive size, a whale shark is absolutely it is safe because, like the giant shark and the bigmouth shark, it feeds exclusively on plankton and other small organisms, which it filters by drawing water into itself.

The whale shark is the only species in the genus Rhincodon, which in turn is the only one in the family of whale sharks (Rhincodontidae). Whale sharks belong to the order Wobbegongidae.

External signs
Whale sharks are gray, brown or bluish in color, with a lighter belly and a back covered with light stripes and spots. Whale sharks have two dorsal fins, as well as pectoral and anal fins and five gill slits. The large mouth stretches across the entire width of the flattened and blunted front part of the head. Due to their size and unusual coloring, whale sharks cannot be confused with other fish.

Whale sharks prefer water temperatures between 21 and 25 °C and are distributed throughout the world, found in almost all warm tropical and subtropical seas. They can be found especially in abundance in regions with high seasonal plankton content.

Behavior
Whale sharks actively absorb water (up to 6000 l/h), passing it through their gills, equipped with a comb-shaped filtration apparatus. It consists of cartilaginous plates that connect the individual gill arches to each other like a lattice, and on which skin denticles are located. To meet their enormous food needs, whale sharks filter from the water, in addition to plankton, small fish, as well as other small sea inhabitants.

Until April 1828, when a few brave African fishermen managed to harpoon this huge fish, the whale shark was a ghost that was rarely seen, about which all sorts of tales were often told, but which had never yet been caught and studied. Many years have passed since then, quite a lot of whale sharks have been caught and a lot has been learned about them, but to this day they never cease to amaze us with their size. Their length reaches 20 meters.

In 1912, a whale shark weighing 13.5 tons was caught off Nants Key, Florida. Their sizes are so large that it is almost impossible to accurately determine their weight. Dr. E. W. Gudger, who has devoted his entire life to the study of whale sharks, believes that 12 meters is only average length these huge sharks, and that some of them reach a length of 23-25 meters. The weight of such a shark, calculated according to the formula proposed by Dr. Gudger, should be at least 20-25 TONS. The log books of ships from all countries describe cases of collisions between a whale shark and a ship. Here is a typical note made by the captain of a schooner after such a collision, which took place near Cape San Lucas, off the southern tip of California: “A huge shark appeared on the starboard side and struck the ship with such force that the helmsman lost his grip on the wheel. The shark's tail rose 2.5 meters above the ship's bulwark and more than 4 meters above sea level. The order was given to turn off the engine because a fish had broken the propeller. When the fish backed up, we were able to take a good look at it: it had a speckled coloring and reached at least 9-10.5 meters in length. When the ship was put into dry dock upon arrival at the port, it was discovered that the hull and rudder had been seriously damaged.”

Judging by numerous evidence, whale sharks appear purely by chance in the path of a ship and certainly do not have the intention of attacking it. Perhaps they are driven by curiosity that is fatal to them, and sometimes to the ship. If whale sharks had attacked a ship instead of exposing themselves to it, we would never have read one of best books written about the sea: “KON-TIKI” by Thor Heyerdahl. The author tells how one day, when he climbed onto the raft after swimming, there was a cry: “Shark!” A fish “with the biggest and ugliest face” that the people on the raft had ever seen swam right behind the stern. Heyerdahl says that she was so terrible that, “rise from the bottom of the sea yourself sea devil, he couldn’t have frightened us more.” But the Kon-Tiki scientists had nothing to fear. Whale sharks are so lethargic that people literally, not figuratively, walked on their backs.

Here is what an employee of the Scripps Institution of Oceanography says, who once, together with a group of scuba divers, came across a whale shark: “We climbed on the shark and examined it thoroughly, even looked into its mouth. She didn't seem to notice us at all. Only when we began to touch her snout did she slowly go deeper. But soon it went up again, and we climbed it again.” There are many stories about the lethargy and lethargy of whale sharks. However, we should not forget that fish are such gigantic size can be dangerous due to its size alone. When a ten-meter whale shark was accidentally caught in a net off Fire Island, New York, it took three hours to subdue it. Trying to free herself, she can easily kill a person, or even two, with a blow from her powerful tail. True, not a single such case has been registered so far.

The whale shark feeds on crustaceans and small fish, which it pulls along with the water into its huge mouth, where, bending slightly, an adult can fit. The whale shark has a huge number of tiny teeth (scientists took the trouble to count them in one specimen - there were 15 THOUSAND of them). All these teeth encircle the mouth in a narrow band just behind the shark’s mouth. They cannot bite or crush food, and their only purpose is to hold in their mouths what gets into it along with water. When a whale shark is in motion, it draws in water with its mouth and then releases it through its gill slits. Passing the gill slits, the water is filtered through a thick gill “sieve”, consisting of cartilaginous partitions closely placed one to the other, connecting the gill arches. Thus, small crustaceans and fish that fall into its mouth with a current of water find themselves in a trap, the only way out of which is into the shark’s throat.

The whale shark's throat is very narrow, and the esophagus turns to the stomach almost at a right angle. It is clear that she cannot swallow a large fish, much less a person who happens to be in her path. In the stomach of one huge shark, presumably a whale shark, 47 buttons, 3 leather belts, 7 gaiters and 9 shoes were found. This discovery caused the most different interpretations. Some said that this shark was not a whale shark at all, others that it was a whale shark that had swallowed supplies of dry goods that accidentally ended up in the sea, and even that the objects found in its stomach were the only traces of the people it had swallowed.

We know almost nothing about how the whale shark reproduces, although it has been observed for over a hundred years. There are only a few scattered facts that help solve this mystery. In 1910, a female whale shark dissected in Ceylon was found to have 16 egg capsules in her oviducts. In 1955, two hundred kilometers from Port Isabel in Texas, at a depth of fifty-seven meters, a similar capsule was discovered. It contained an embryo of a whale shark, easily identified due to its characteristic coloring - white spots and stripes on a dark background. The egg was 63 centimeters long and 40 centimeters wide.

Now there was no longer any doubt that whale sharks produce their offspring using eggs. The whale shark is a pelagic fish. It is found in the tropical zones of the Atlantic, Pacific and Indian Oceans. But it can also be found further north, at the latitude of New York and even Massachusetts.

Of all those existing in the world. The whale shark's size is second only to the estimated maximum size of the extinct megalodon.

About the life of a whale shark

For a long time it was unknown to scientists; only those who traveled to the world knew about it. tropical waters sailors. The meeting with such a giant, of course, surprised and frightened them, and these emotions contributed to the emergence of many beliefs about monsters living in the oceans.

First scientific description

Zoologists first learned what a whale shark looks like in 1828. At that time in South Africa worked by Andrew Smith, an English naturalist. He was given a small (4.50 m long) whale shark caught in Table Bay, on the shore of which the city of Cape Town is located. This is a small bay in southwest Africa in the Atlantic Ocean.

Smith did detailed description this new fish for science and gave it the Latin name - Rhincodon typus. This specimen was stuffed and subsequently sent to Paris. There is information that it is still kept in one of the museums in Paris. But this information has not been verified, and it is difficult to say in which museum this unique exhibit can be seen.

Characteristic features of appearance

The whale shark has a unique appearance, by which it is recognized at first sight.

A huge powerful body with a relatively small head.
The head is flat, as if flattened; at the end of the snout this flattening is more pronounced.
The mouth is terminal (located at the end of the snout); most other sharks have a mouth under the snout.
The width of the mouth is up to one and a half meters. When fully opened, the mouth takes the shape of a very wide oval.
In the corners of the mouth, leathery outgrowths similar to small antennae are clearly visible.
The gill slits are wide and number five. They are long (up to 1.5 meters for a 12-meter specimen).
Immediately behind the head, the body thickens greatly, forming a gentle hump, and then becomes thinner.
There are two dorsal fins located closer to the caudal fin, the first of which is larger and looks like an equilateral triangle.
The tail fin is characteristic of all sharks - it has different blades, the length of the upper blade is one and a half times longer than the lower one.
Behind the head, along the sides and back, folds of skin are clearly visible, which stretch like long ridges to the tail.
Large pectoral fins (up to 2.4 m long).

This is what a whale shark looks like through the eyes of the famous traveler Thor Heyerdahl: the description is quoted from his book (Thur Heyerdahl. The Kon-Tiki Expedition. “Ra”. Translated from Norwegian by L. Zhdanov. - M.: Mysl, 1972.)

“The head belonged to a gigantic monster, and it was so huge, so terrible that he himself sea serpent, had he appeared before us, he would not have struck us more strongly. Small eyes sat at the edges of the wide and flat muzzle, the toad's mouth with long fringes at the corners was at least one and a half meters wide. The powerful body ended in a long thin tail; the sharp vertical fin indicated that this was, in any case, not a whale. The body seemed brown in the water, but both it and the head were dotted with small white spots.

Skin and color

If you look at a photo of a whale shark, its color is striking:

The main color of the dorsal part of the body is dark gray with brown or blue shades.
Against this background, along the back and sides, there is a peculiar regular pattern of narrow transverse stripes of dirty white color, interspersed with rows of the same dirty white round spots.
The head and pectoral fins are decorated with smaller and randomly located spots.

The skin of the body and fins is also “decorated” with a pattern of large number scratches This pattern is individual for each individual and does not change throughout life.

It is important that the spotted pattern is also constant for an individual. These patterns easily identify a specific whale shark, giving scientists the opportunity to conduct scientific observations of this species.

To identify differences in the spotted patterns on the skin of whale sharks, they used equipment used by astronomers to study the location of celestial bodies. The instruments were also effective in showing differences in the spotted patterns on the sharks' skin, as well as differences in the positions of stars in the sky.

The thickness of the skin on the back of a whale shark is up to 14 centimeters in large individuals. It is covered with the usual “skin teeth” - placoid scales, consisting of a basal plate and a sharp spine extending upward from it. However, the whale shark has scales that are different from those of other sharks: the plate is very small, and the sharp spines are well developed and strongly curved back. Perhaps this serves to improve the hydrodynamic properties of the shark's body.

The ventral side of the body, also covered with placoid scales, is characterized by thinner skin than on the back (about 30% thinner). Very often the shark turns its back to the approaching diver, probably due to the weaker protection of its belly.

Dimensions of the largest shark

The maximum size of the whale shark was clarified until the end of the 1990s, when the first reliable scientific information appeared about the largest specimen of this type of fish: its length turned out to be 20 meters. How much does a whale shark of this size weigh? Its weight was 34 tons.

Ichthyologists use every opportunity to take measurements different parts the body of this sea giant. This happened in the southern state of Tamil Nadu in 2002 in India, when a young individual ended up in the hands of Indian scientists. Scientists measured all her body parameters with high accuracy:

The length of the whale shark was 478 centimeters.
The mouth was 77 centimeters wide.
The length of the upper large blade of the caudal fin was 115 centimeters.
Eye parameters: length – 4 centimeters, width – 3.5 centimeters.

Data were obtained on how much a whale shark almost 5 meters long weighs: weight 1700 kg. Most often, people encounter whale sharks no larger than 12 meters.

Favorite places of whale sharks in the ocean

Where does the whale shark live? Not in cold water. She loves warmth, and therefore can be found in the low latitudes of all oceans. The highest latitude where it descends to the south and rises to the north is 40 degrees, but very rarely. Its usual range is south of 30 degrees north and north of 35 degrees south latitude.

The water temperature of the surface layer in the areas where the whale shark lives is in the range of 21-25 degrees, with a constant influx of deeper, cooler layers of water. The salinity in these places is very high - up to 35 ppm.

Scientists suggest that such preferences for water parameters in sharks are associated with a large number planktonic organisms in these places, which form the basis of its diet. There is information that whale sharks have been spotted even in river mouths, where salinity is lower than oceanic, but there are dense accumulations of plankton.

Whale sharks have favorite places in the world’s oceans, where they are found more often and in large numbers:

Taiwan Island and Seychelles– here they are present throughout the year, although the maximum occurs in summer months and the end of autumn (according to the generally accepted calendar).
The areas adjacent to the east and southeast coasts of Africa are the second favorite place for whale sharks, but also with seasonal peaks in numbers. Scientists estimate that 1/5 of the world's shark population lives off the coast of Mozambique.
The Philippines, some places off the coast of Australia, Chile and the Gulf of Mexico are places where whale sharks are common.

Whale sharks rarely visit other places in the world's oceans within their range and only seasonally.

Whale sharks' favorite food and feeding method

Is the whale shark a predator or not? If you look into her mouth, the answer is obvious. She has a huge number of teeth - several thousand (maximum up to 15,000). Even the most gigantic whale shark has small, completely “not shark” teeth, no more than 6 millimeters high.

Of course, this size of teeth is a very peculiar adaptation to obtaining food, because their owner does not bite prey, like all her other relatives (with the exception of giant shark). Such a huge number of teeth helps to “lock” the prey in the mouth, in other words, to close the mouth very tightly.

Like baleen whales, this gigantic shark slowly “grazes” in the ocean, filtering planktonic organisms from the water. The filtering apparatus is cartilaginous plates (20 of them), located between adjacent gill arches. This whole structure looks like a lattice with a mesh width of no more than 3 millimeters. These plates also contain skin teeth.

With its mouth wide open, the shark takes in water, then closes it. The water is filtered through the gill slits. And all the planktonic inhabitants that fall into the shark’s mouth remain in the mouth and are directed through the esophagus, which is unusually narrow for such a giant (only 10 centimeters in diameter) into the stomach. It is clear that in order to get enough of such small food, you need to constantly get it. This is what whale sharks do constantly – 7-8 hours every day. In one hour, up to six thousand cubic meters of water are passed through the shark’s mouth.

Watch the video and notice how wide the whale shark's gill slits open as it filters the water and food.

In the photo of a whale shark, you can see how a school of small fish is forcefully drawn into its wide-open mouth.

Therefore, the answer to the question “is a whale shark a predator or not” is the word “no”.

The menu consists of everything that ends up in her mouth and is able to “squeeze” into her “miniature” esophagus. Here is the list:

zooplankton (jellyfish, small squids, crustaceans and others), the size of which is measured in several millimeters;
medium-sized species of schooling fish (sardine, anchovy, small mackerel and sometimes tuna).

When a whale shark feeds, its movement speed is minimal, and it often stops and hovers in the water. It happens that she holds the body in an almost vertical position to the surface. It often sucks in food objects floating in the very surface layer of water: usually these are small copepod crustaceans and fish larvae. In this case, a small part of its mouth is visible above the water.

Although the whale shark bears the title biggest fish on the planet, still remains practically harmless to humans. It has no natural enemies, but is constantly on the move, absorbing small fish and other “living dust”.

Description of a whale shark

The whale shark was noticed by ichthyologists relatively recently. It was described for the first time in 1928. Its huge outlines were often noticed by ordinary fishermen, from where fables about a huge monster living in the surface of the sea were spread. Various eyewitnesses described her in a terrifying and unsightly form, without even realizing that she was harmless, apathetic and good-natured.

This type of shark amazes with its large dimensions. The length of a whale shark can reach up to 20 meters, and the record weight reaches up to 34 tons. This is the largest-sized specimen that was captured at the end of the last century. The average size of a whale shark ranges from 11-12 meters, with a weight of about 12-13.5 tons.

Appearance

Despite such impressive dimensions, the choice of name was influenced by the structure of her mouth, and not her size. The point is the location of the mouth and the peculiarities of its functioning. The whale shark's mouth is located clearly in the middle of its wide snout, and not below, like many other species of sharks. She is very different from her brothers. Therefore, a special family has been allocated for the whale shark with its own class, consisting of one species, its name is Rhincodon typus.

Despite such an impressive body size, the animal can hardly boast of equally powerful and large teeth. The teeth are very small, reaching a length of no more than 0.6 mm. They are located in 300-350 rows. In total, she has about 15,000 small teeth. They hold small food in the mouth, which subsequently enters the filtering apparatus, consisting of 20 cartilaginous plates.

Important! This species has 5 pairs of gills and relatively small eyes. In an adult, their size does not exceed a tennis ball. Interesting fact: the structure of the visual organs does not imply the presence of an eyelid as such. During an approaching danger, to preserve vision, a shark can hide its eye by pulling it inside its head and covering it with a fold of skin.

The body of a whale shark thickens from the head to the base of the back, forming a raised area in the form of a gentle hump. After this section, the body circumference decreases until the tail. The shark has only 2 dorsal fins, which are moved back towards the tail. The one closer to the base of the body looks like a big one isosceles triangle and larger in size, the second is smaller and located a little further towards the tail. The tail fin has a typical sharply asymmetrical appearance, characteristic of all sharks, with the upper blade elongated by one and a half times.

They are gray in color with bluish and brownish splashes. The shark's belly is cream or whitish in color. On the body you can see stripes and spots of a light yellowish color. Most often they are located in a prim in the right order, stripes alternate with spots. There are also spots on the pectoral fins and at the head, but they are located more chaotically. There are more of them, but they are smaller in size. At the same time, the pattern on the skin of each shark remains individual and does not change with age, which has a beneficial effect on tracking their population.

It is quite interesting that in the tracking process itself, ichthyologists are helped by equipment for astronomical research. There are special instruments whose task is to compare and contrast images of the starry sky; this helps to notice even minor differences in the location of celestial bodies. They also effectively cope with the location of spots on the body of a whale shark, accurately differentiating one individual from another.

The sides, to improve hydrodynamic properties, are covered with poorly developed scales. On the belly, the skin of a whale shark is a third thinner than the main layer. That is why, when curious divers approach, the animal turns its back to him, i.e., the most naturally protected part of its body. In terms of density, the scales themselves can be compared to shark teeth, which is provided by a special coating of an enamel-like substance - vitrodentin. This placoid armor is common to all shark species.

Whale shark dimensions

The average whale shark grows up to 12 meters in length, reaching a weight of about 18-19 tons. To put this into perspective, these are the dimensions of a full-size school bus. Just one mouth can reach 1.5 meters in diameter. The largest specimen caught had a girth of 7 meters.

Lifestyle, behavior

The whale shark is a slow-moving animal with a calm, peaceful disposition. They are “sea vagabonds” and little is known about their lives yet. They swim undetected for most of their lives, occasionally appearing off the coast of coral reefs. More often, their diving depth does not exceed 72 meters; they prefer to stay closer to the surface. This fish has little maneuverability; it cannot suddenly slow down or stop due to the lack of a swim bladder and other structural features of the body that provide an influx of oxygen. As a result, he often gets injured when bumping into passing ships.

This is interesting! But at the same time, their capabilities go far ahead. The whale shark is capable of staying at a depth of about 700 meters, like most other shark species.

When swimming, the whale shark species, unlike others, uses not only the tail part, but two-thirds of its body for movement. The urgent need for a regular supply of food forces them to often stay close to schools of small fish, for example, mackerel. They spend almost all their time searching for food, breaking off only for short periods of sleep, regardless of the time of day. They most often drift in small groups of several heads. Only rarely can you see a large school of 100 heads or a shark traveling alone.

In 2009, a concentration of 420 whale sharks was spotted off the coast of coral reefs, so far this is the only reliable fact. Apparently, the whole point is that in August there is a lot of freshly spawned mackerel caviar off the coast of Yucatan.

Every year, for several months, hundreds of sharks begin to circle the coast of Western Australia near the largest reef system, Ningaloo, which borders it. Almost all creatures, small and large, come to feed and breed off the coast of Ningaloo when the reef is bustling with life.

Lifespan

Experts have differing opinions on the issue of whale sharks reaching sexual maturity. Some believe that individuals that reach 8 meters in length can be considered sexually mature, others – 4.5 meters. It is assumed that the animal at this moment reaches the age of 31-52 years. Information about individuals who lived more than 150 years – clean water myth. But 100 is a real indicator of shark longevity. The average figure fluctuates around 70 years.

Range, habitats

To represent their habitat, it is important to understand that whale sharks live in areas where food is concentrated for survival. They are also heat-loving animals, preferably choosing areas with water heated to 21-25 °C.

Important! You will not find them north or south of the 40th parallel, most often living along the equator. This type found in the Pacific, Indian and Atlantic oceans.

Whale sharks are primarily pelagic fish, meaning that they live in the open sea but not in the deep ocean. The whale shark is usually found in coastal waters South Africa, Central America and South America. It is often seen close to shore while feeding along reef shores.

Whale shark diet

One of the most important aspects of whale shark nutrition is their role as filter feeders. Teeth do not play a big role in the feeding process; they are too small and only participate in the process of holding food in the mouth. Whale sharks feed on small fish, mainly mackerel, as well as small plankton. A whale shark roams the ocean, sucking large number water along with any small nutritious living creatures. This feeding pattern is characteristic of two other species - giant and meter-long pelagic largemouth sharks. However, each feeding process has its own fundamental differences.

The whale shark powerfully sucks in water, then feeds food through filter pads that cover the entrance to its mouth. These filter pads are full of millimeter wide pores that act like a sieve, allowing water to pass through the gills back into the ocean while selecting the desired food particles.

Let's find out something interesting about this giant.

For a long time, the whale shark remained unknown to science. She was met only by sailors sailing in tropical seas, whose stories, apparently, contributed greatly to the spread of beliefs about sea monsters. The first acquaintance of zoologists with a whale shark dates back to 1828, when a 4.5-meter whale shark was caught off the coast of South Africa in Table Bay. This specimen fell into the hands of the famous English naturalist Andrew Smith, who worked in South Africa, who described the whale shark as the species Rhincodon typus.

A stuffed specimen of this first scientifically described whale shark was sent to Paris, where it is currently kept in a museum. The rarity with which this shark ended up in the hands of researchers is explained both by its small numbers and its enormous size and, accordingly, the difficulty of transportation. Currently, the whale shark is still one of the least studied sharks.

Sir Andrew Smith (1797-1872), who described and classified the whale shark in 1828 Even in the 20th century, the whale shark was extremely little known outside a narrow circle of specialists. There is a known case when in 1911 an English steamer, en route to India, hit a whale shark with its nose, apparently about 17 m long, and dragged it on the stem for 15 minutes. The ship's passengers, apparently unfamiliar with the whale shark, thought that this was a species unknown to science and decided to give the fish the Latin name Piscis rudyardensis, i.e. “Rudyard's fish” - in honor of the writer Rudyard Kipling who was on board. Even by the early 1970s, only about a hundred copies had fallen into the hands of scientists, although by 1987 this number had increased to 320. The lack of reliable data led to the fact that different sources you could meet the most various information about the whale shark. For example, when a very large whale shark was caught in the Gulf of Thailand in 1925, it was stated that its length was 18 m. However, it later turned out that this figure was greatly exaggerated.

The whale shark lives in tropical and temperate warm seas and, despite the fact that it is mainly found in coastal waters, sometimes it comes quite close to the shore, swimming into lagoons or coral atolls, as well as into the mouths of rivers and estuaries.

The whale shark can dive to depths of up to 700 meters. Living solitary most of their lives, they sometimes gather in groups in regions with high seasonal plankton content.

The whale shark is difficult to confuse with other fish - in addition to its huge size, it is distinguished by its characteristic appearance. The whale shark has a powerful and thick body, and a relatively small head. The shape of the head is very peculiar - it is strongly flattened, and becomes increasingly flatter towards the end of the snout. Gill slits 5; they are extremely wide and long (for a 12-meter shark - about one and a half meters). The mouth is at the end of the snout, and not under it, like most other sharks. The mouth is very wide, reaching one and a half meters in width (the 12.8-meter specimen had a mouth width of 1.36 m). It can open quite strongly and, when fully extended, takes on the appearance of a wide oval. At the corners of the mouth there are leathery outgrowths, like small antennae.

Vivid description The appearance of the whale shark was given by the famous Norwegian explorer Thor Heyerdahl, who observed this fish while sailing on the Kon-Tiki raft:
“The head belonged to a gigantic monster, and it was so huge, so terrible that the sea serpent itself, if it had appeared in front of us, would not have struck us so much. Small eyes sat at the edges of a wide and flat muzzle, a toad’s mouth with a long fringe at the corners was at least one and a half meters wide. The powerful body ended with a long thin tail, a sharp vertical fin indicated that in any case it was not a whale. In general, the body seemed brown in the water, but both it and the head were dotted with small white spots. lazily swam after us, squinting like a bulldog and quietly working its tail... Now we could get a very close look at this giant... Even the rich imagination of Walt Disney could not have created a more scary monster."

The eyes are very small and deep-set, located close to the end of the snout almost at the edges of the mouth. They are located on the line separating the dark color of the back and sides from the white belly. The largest sharks have eyes barely the size of a golf ball (about 5 cm in diameter). The whale shark does not have a nictitating membrane, but the eye can be closed by a thick fold of skin that moves forward. If some fairly large object is too close to the eye, the shark draws the eye into its orbit and closes it with this fold. This is a unique trait among sharks. Almost immediately behind the eyes there are round squirts

The body of the whale shark behind the head becomes thick, the back rises in the form of a gentle hump. The body is at its greatest thickness just behind the head, and then begins to become thinner. There are two dorsal fins, both of them are shifted far back. The first fin is high and wide, in the shape of an almost equilateral triangle. The caudal fin, like that of all sharks, is sharply asymmetrical; its upper lobe is approximately one and a half times longer than the lower one. At the same time, there is no notch on the upper blade, characteristic of the tail fins of most sharks. The 12-meter fish had a tail fin width of 4.8 m, length pectoral fins- 2.4 m. On the back of the body there are several longitudinal folds of skin in the form of long ridges on the sides and on the back, reaching all the way to the tail.

The number of teeth in a whale shark is extremely large and can reach several thousand - even up to 15 thousand. The shark, which had 3 thousand teeth in its mouth, had about 300 rows on each jaw. The teeth are small, even in the largest sharks not exceeding 6 mm in length. The whale shark's brain, relative to its body size, is significantly smaller than that of other sharks, such as the white shark. Its structure, studied using magnetic resonance imaging, showed noticeable differences from the brains of other sharks. The whale shark's cerebellum is more developed than others cartilaginous fish. Other features of her brain may be an adaptation to the herd lifestyle. The whale shark has a relatively much smaller liver than most other sharks. Therefore, the whale shark often swallows air to regulate the buoyancy of the body (in other sharks, the liver, which contains a large amount of fat and has a density less than the density of water, increases buoyancy).

Almost nothing is known about how the whale shark reproduces, although it has been observed for over a hundred years. Until very recently, information about this was very scarce and scattered. It is known that the whale shark is ovoviviparous - embryos develop in egg capsules, hatching from them in the womb, although previously scientists assumed that this fish lays eggs. Whale shark eggs and embryos were only discovered in the 20th century. In 1910, a female whale shark caught off Ceylon had 16 egg capsules in her oviducts. In 1955, 200 km from Port Isabel (English) Russian. in Texas, a similar capsule was discovered at a depth of 57 m. It contained an embryo of a whale shark, easily identified due to its characteristic coloring - white spots and stripes on a dark background. The egg was 63 cm long and 40 cm wide.

However, to date only one pregnant female, harpooned in 1995, has been studied in detail. It was 10.6 m long and 16 tons in weight and had 307 embryos, ranging from 40 to 60 cm in length. One of the smallest known specimens of a whale shark, a calf 59 cm long, is kept in Russia, in the museum of the Research Institute of Fisheries and Oceanography. At birth, baby sharks are very small in size, about half a meter. They have significant internal reserves nutrients, allowing them to survive for a long time without an external source of food. There is a known case when in Japan, an unborn, but alive and fully formed baby shark was removed from the womb of a caught whale shark. He was placed in an aquarium and went completely without food for the first 17 days.

Research from the 1990s and 2000s suggests that the whale shark has an exceptionally long period of sexual maturation. This fish reaches sexual maturity only at the age of 30, 35 and even 50 years, although its life expectancy is very long - up to 70 and even, according to some sources, 100 years. The data sometimes found about 150-year-old whale sharks seems to experts to be overestimated. Sexual maturity occurs when the shark reaches a length of 4.4–5.6 m, according to some sources, and 8–9 m, according to others.

In the studied schools of whale sharks, there is usually an excess of males over the number of females. Sometimes this disproportion is very large - for example, a study of a herd of whale sharks off the west coast of Australia (at the Ningaloo reefs (English)Russian, where the largest in Western Australia marine reserve) revealed that females appear to make up only about 17% of total number sharks in this herd. However, the small number of females may be explained by the fact that this area is used by sharks for feeding rather than for reproduction. Of the total number of male whale sharks studied during the mentioned studies at the Ningaloo reefs, only 9.3% of males with a body length of 6 to 8 m were sexually mature, and among those whose length was 8–9 m, 36.6%. In general, apparently, 95% of males reach sexual maturity after reaching 9 meters in length.

According to most descriptions, the whale shark is exceptionally lethargic and slow. The fish prefers to stay in the near-surface layer of water, usually no deeper than 70 m. During deep dives, the whale shark, according to data obtained from tagging, can descend to a depth of 700 m, where the water temperature is about 7°. Whale sharks swim by undulating the entire back of their body, not just the caudal peduncle like most other sharks; in such smooth oscillations, the fish uses about 2/3 of its body length. The whale shark swims very slowly, under normal conditions - about 5 km/h, and often even slower. According to some reports, whale sharks often stay in the vicinity of schools of schooling fish, especially mackerel.

The whale shark is apparently active around the clock and sleeps short periods regardless of the time of day (perhaps ships encounter sleeping sharks). Groups of whale sharks have been observed feeding in the dark.

Whale sharks live in small groups or, less commonly, alone and only occasionally form aggregations of up to 100 animals. IN exceptional cases groups of whale sharks can number hundreds of fish. In 2009, a group of specialists from the Smithsonian Institution recorded a concentration of 420 whale sharks off the coast of Yucatan. Apparently, sharks gather in large groups in these places every August - they are attracted by a large amount of freshly spawned mackerel eggs, which sharks readily eat. Such concentrations of whale sharks have never been observed in other areas of the ocean.

The feeding method of the whale shark is similar to that of baleen whales, which also feed on plankton. However, if baleen whales filter water with food through the baleen plates growing from the palate of the upper jaw, then the whale shark’s filtering apparatus consists of 20 cartilaginous plates connecting individual gill arches to each other like a lattice (the side of its cells is only 1-3 mm) , and on which the skin teeth are located. When feeding, a whale shark is capable of passing up to 6 thousand cubic meters of water per hour through its mouth. Having filled the mouth with water and plankton, the shark closes it, after which the water is filtered through the gill openings. Then the filtered food organisms enter the stomach through a narrow (no more than 10 cm in diameter) esophagus. It is in connection with this method of feeding that the teeth of the whale shark are very small and numerous; they serve not for biting, but for “locking” prey in the mouth.

The whale shark everywhere feeds on almost everything that falls into its mouth and that it can swallow. These are primarily various planktonic organisms several millimeters in size - crustaceans, small squids, jellyfish, etc. Small schooling fish are also eaten - anchovies, sardines, small mackerel, and even small tuna. The presence of whale sharks is often a sign to fishermen that commercial fish, for example, tuna - as a rule, whale sharks stay where there is a large amount of plankton and, therefore, other fish that feed on it. When feeding, the shark moves very slowly - about 1 m/s, and often almost stops, hovering in the water, and , sucking up plankton, sways up and down, moving its head to the sides.

Often the shark stays almost vertical to the surface. Then, if the excitement is strong enough, in the depressions between the waves you can see the head of a shark emerging from the water. A case is described in which a whale shark sucked up plankton (apparently larvae coral polyps) from the surface of corals; at the same time, the fish was kept at an angle of 45° to the reef surface. At Ningaloo Reefs mass gathering The abundance of whale sharks is explained precisely by the high density of polyp larvae, as well as small planktonic animals that feed on them and also serve as food for the whale shark. Often the shark sucks in food located directly below the surface of the water (near-surface plankton consists mainly of small crustaceans, such as copepods and sergestids, bristlejaws, as well as fish larvae). Then upper part its mouth - about 15% in height - appears above the water. A shark can graze near the surface for a very long time, spending on average about 7.5 hours a day.

A feeding shark makes 7-20 swallowing movements per minute, with movements of the jaws occurring simultaneously with movements of the gill slits. When there is an abundance of food, the fish eats so much that its belly protrudes greatly. It was estimated that a shark 4.33 m long swallowed about 1.5 kg of food during an hour of feeding in water with a normal plankton density (4.5 grams per cubic meter), and another individual, 6.22 m long, swallowed 2.76 kg. This roughly coincided with the food consumption of whale sharks observed in aquariums.

And this is how she drags the catch from the nets

Here's a video for you:

There have been virtually no estimates of the number of whale sharks, so there is no accurate data on their population. In any case, whale sharks have never been numerous in the past. There is evidence that there are only about 1 thousand whale sharks left on the entire earth - if this information is correct, then the whale shark is one of the most rare fish In general, it is on the verge of extinction. Some sources, however, report that this figure applies only to those specific individuals that scientists are able to track.

In places where the whale shark is relatively common, it is sometimes caught by fishermen, although, in general, due to its small numbers, this fish is rarely caught by fishermen. Sources from 1971 (i.e., when the whale shark was somewhat more numerous than it is now) emphasized that its commercial importance everywhere is very small. Normal way The hunting of these sharks is the same as hunting for whales - with the help of a harpoon. Due to its sluggish disposition, the whale shark is relatively easy to catch. There are descriptions of how fishermen from the shores of the Persian Gulf caught whale sharks by swimming up to them and threading a hook into their mouths. They are also caught fixed networks, although often the whale shark is caught as bycatch in nets set for other fish. In 1995, Taiwanese fishermen caught approximately 250–272 sharks, of which 158 were killed using hand harpoons, the rest were caught using nets.

Places where whale sharks are traditionally caught include many areas of the South and Southeast Asia. They are relatively often caught off the Philippines and especially Taiwan, where whale shark meat is highly prized. In Taiwan, before the ban on their fishing, these sharks were caught in greater quantities than anywhere else. The local name for whale shark literally means “tofu shark”, since its white and tender meat is compared in taste, color and consistency to tofu. The whale shark is one of the fish traditionally caught in the Arabian Sea by Indian and Pakistani fishermen. In coastal areas of Pakistan, whale shark meat is eaten fresh or salted, and the liver is used to extract oil for impregnation of fishing boats. Fishermen in the Maldives caught whale sharks exclusively for oil (20-30 whale sharks were caught annually in the Maldives). Whale sharks were also hunted in India for the oil obtained from the liver. Whale shark fishing also exists in the Atlantic Ocean, off Senegal.

Even in the recent past, whale shark meat was sold cheaply in the markets of South and Southeast Asia - in 1985, a whale shark weighing several tons was sold in Taiwan for just a few Taiwanese dollars. In the 2000s, prices for whale shark meat increased markedly, reaching NT$7 per kilogram; Moreover, it is known that in Taiwan, whale shark meat is valued lower than, for example, basking shark meat. The above-mentioned young shark weighing 1700 kg, caught by Indians off Tuticorin, was sold for 1200 rupees, i.e. about 30 dollars. Currently, you can still find products obtained from whale sharks on legal sale - for example, in Hong Kong in 2010, there were cases of trade in dried whale shark fins at a price of about 300 dollars per piece, used to prepare a delicacy soup. According to some estimates, the fins of up to 1,000 whale sharks end up on Chinese markets every year.

Whale shark skin is used as leather. Parts of the whale shark carcass can also be used in traditional Chinese medicine.

The plankton-eating whale shark is generally regarded as posing absolutely no threat to humans. This inert, sluggish, slow-swimming fish never attacks a person, which divers readily take advantage of, often swimming close to it. One of the American oceanographers who met a whale shark wrote:

“We climbed onto the shark and examined it thoroughly, even looked into its mouth. It seemed that it did not notice us at all. Only when we began to touch its snout, it slowly went into the depths. But soon it went up again, and we climbed up again her."

However, a whale shark can be considered potentially dangerous given the possibility that a wounded (eg harpooned) fish could become enraged and crash a boat or drown a person with a blow from its tail. Therefore, hunting for it is associated with a certain danger.

Like all sharks, giant whales have negative buoyancy, but their anatomy helps them float.

Thanks to this very “non-buoyancy”, few people can see dead whale colossi: after death, the bodies of whale sharks slowly sink to the bottom. However, in lately Terrible discoveries became more frequent: huge bodies of dead fish began to be found on the coasts of the Philippines, Taizhou, Maldives, and Yucatan.

During an external examination, as a rule, no injuries were detected. But dead sharks appeared again and again, and, interestingly, not just washed up on the shore, but drifting near the shore, which, according to all the laws of biology, is impossible for this species. What is the mystery?

Similarly, the bodies of dead whales often drift on the surface of the ocean. But it’s possible, the anatomy is different there. But the bodies of whale monoliths found are nonsense. Unfortunately, fishermen and residents of coastal villages were not too puzzled by such questions, and, delighted with the unexpected rich catch, they simply cut up the dead carcass and used it for food - fortunately, no signs of decomposition were found.

Strange finds continued to appear, and eventually researchers became interested in the dead whale sharks. The first version of the death of the whale giants was based on reports of the latest crashes of tankers transporting oil. Although the carcasses were found extremely far from the disaster sites, scientists suggested that the affected sharks managed to move thousands of kilometers before dying. They checked the dead bodies, but found no traces of oil.

Another version was poisoning toxic substances, which someone deliberately lowered into the water. However, dead filter feeders were found in completely different parts of the world, so this version was also not justified. What happened to the most big fish on the planet?

And then, during a microbiological study, they discovered that cartilage cells The sharks found are full of gas bubbles. This gas helps the carcasses float on the water. Plus, the bodies of the dead giants seemed to be preserved in natural substance, similar in structure and action to formaldehyde. Thanks to the preservative, the bodies of dead sharks could not decompose for months. But what caused these changes?

Histological and microbiological analyzes failed to identify the causative agent of the strange disease, and it seemed that the research had reached a dead end. The case of the dead sharks has been declared an "ichthyological mystery." The bodies were locked in research tanks to monitor the dynamics of decomposition.

And for good reason: after a few months, changes began to occur in the carcasses of the dead sharks: the gas from the cells evaporated, and the damaged cells slowly began to disintegrate. At this stage, they first started talking about a virus called Viridae Rhincodon.

It turns out that this tiny virus is carried by bacteriophages and zooplankton - the typical food of whale sharks. In this case, the affected microorganism, like intermediate host, the virus does no harm. But then the plankton is eaten by a whale shark. It is known that giant whales do not constantly swim with their mouths open, filtering tons of water, but open their jaws only when they find food.

So, having stumbled upon a stream of plankton, the whale shark absorbs it, and it becomes infected. Once in the body of the fish, the virus is released and penetrates the cells, where it multiplies and produces gas. At this stage, all metabolic processes slow down and the sick fish gradually dies.

The affected cells become home to new tiny viruses, and during this period it is almost impossible to detect them, since each cell represents Viridae Rhincodon - with all its pathogenic properties.

In order for the final ripening of virions to occur, and they do not get into the water ahead of time, the body of the fish naturally preserved. But after, when the virus is ready for new attacks, the shark decomposes. This is where forced buoyancy comes to the rescue: microplankton, which usually inhabits surface waters, absorbs contaminated water, and the whale shark, which, as a rule, looks for food in surface waters, absorbs contaminated microplankton - and the cycle repeats.

Interestingly, only old or weak fish, with reduced immune defenses, get sick. For a person who has consumed contaminated water or the body of a dead giant, the virus is not dangerous.

By the way, no search for treatment methods has been carried out - such diseases are one of the evolutionary steps, and help clear the species of weak, uncompetitive individuals in order to breed the strongest, most resilient shark - the queen of the salty depths.

Here's an example of how it happens:

A 12-meter whale shark was discovered in the Arabian Sea, off the coast of Pakistan.
This type of shark, the largest fish on earth, is absolutely safe for humans, because... feeds exclusively on plankton.
Whale shark fishing is officially prohibited, so a local fish dealer willingly bought the dead giant.

Mehmood Khan, owner of the Charai fishery, told reporters that a dying whale shark was spotted
at sea ten days ago, at a distance of 150 km from the fishery.

Mehmood Khan's people found the giant shark on Tuesday already dead in shallow waters off the coast of Gadani in Balochistan.

The giant's dimensions were 40 feet (more than 12 meters) in length, 6 feet (1.8 meters) in width. To lift this huge carcass, two cranes were first brought in, but they were not enough, so several more had to be used.

Despite the fact that this is far from the only case of such a “catch” in recent years, a large crowd gathered at the pier. According to marine biologist Moazam Khan, over the past seven years, about three dozen dead whale sharks have been found off the coast of Pakistan.

The operation to lift the 7-ton shark took 4 hours.

The dead shark was sold to fish dealer Qasim Niyabi. The transaction amount was 1.7 million rupees, i.e. more than 18.5 thousand dollars.

The whale shark is one of the fish traditionally caught in the Arabian Sea by Indian and Pakistani fishermen. In coastal areas of Pakistan, whale shark meat is eaten fresh or salted, and the liver is used to extract oil for impregnation of fishing boats

Here is a video of this process

And here is China:

In March 2007, they managed to harpoon and an hour later drag on board a whale shark 10 meters long. For the largest living fish, this one turned out to be not too big: there are specimens reaching 15 and 20 meters in length. The fish weighed about 8 tons - quite enough to feed a family, even a Chinese one.

True, cutting off a piece is not so easy: leather 10 centimeters thick is quite difficult to saw even with a two-handed saw. Despite its terrible size, the whale shark is a completely peaceful creature and does not feed on divers at all, but only on plankton, squid and small fish. And even 15,000 teeth arranged in 300 rows serve it not for biting, but for locking prey in its mouth. Therefore, you can calmly swim next to her, touch her with your hands and even sit astride her. She's not in pain.

sources

Whale sharks are the most big fish in the world. The length of the average representative of the whale shark family varies between 10-12 meters, however, of course, there are also giants - about 18-20 meters in length. The weight of the world's largest fish reaches an average of 12-14 tons. And a 20-meter individual weighing 34 tons, discovered in the late 1990s, allows scientists to speculate about the existence of a wide variety of sizes of this species of animal.

Despite the fact that most people associate the word “shark” with aggression and mortal danger, which is quite applicable to ordinary sharks, whale sharks are distinguished by completely peaceful behavior and do not pose any danger to humans in this sense. Most often, whale sharks do not notice divers at all, allowing those who are especially daring to touch them. These animals can even ride on themselves a little, but do not forget that these giants can cripple and even kill with a blow from their tail. However, you won’t be able to take a “breezy” ride, since whale sharks swim at a speed of no more than 5 kilometers per hour. They usually swim closer to the surface of the water, which is the reason for frequent collisions of sea vessels with these animals.

Comparative sizes of humans and whale sharks

Whale sharks are distinguished by their brown or dark gray coloration, which is covered with yellowish or white spots. However, this fish is easily distinguished from others by its colossal size.

Whale sharks feed on plankton and small sea creatures: They swim slowly with their mouths wide open, after which they close it, release water through 5 gill slits and swallow everything that is left. A huge number of sharp and small teeth (in some individuals it reaches 15,000), arranged continuously in several rows, help to hold prey.

The main habitat of whale sharks is Pacific Ocean and the waters of the Caribbean, however, sometimes they can end up in other warm corners of the World Ocean. Whale sharks, whose population is already small, are endangered due to fishermen in South and Southeast Asia, who catch this type of fish on a huge scale, without at all burdening themselves with the moral aspects of such fishing. For recent years, even despite a total ban on fishing for whale sharks due to the threat of their extinction, poachers continue to catch them. For this reason, the recovery of the whale shark population is very slow.