Thor Heyerdahl called this fish a gigantic monster, so terrible that even the mystical sea serpent could not frighten it more. Of course: a huge mouth, small evil eyes and a thick, powerful body can scare anyone. However, the whale shark (lat. Rhincodon typus) is completely harmless to humans. She feeds on plankton, not paying any attention to divers who strive to ride on her back.
The whale shark is considered the largest ever known modern fish. The length of her body, according to various estimates, reaches 12-14, or even 18-20 meters. It is so unique that it is separated into a separate family and a separate genus with the only kind. But it has no subspecies: even those populations that live far from each other and do not intersect do not have any genetic differences.
Whale shark prefers warm waters low latitudes, where near the surface the water warms up to 21-26 degrees, and from the depths there is a cool influx with a temperature of about 17 degrees. Most often it can be found off the coast of Taiwan and the Seychelles. Also, concentrations of sharks are observed in East and South-East Africa, in Gulf of Mexico, Philippine waters and off the coast of Australia.
Meet a whale shark - great luck. It was not very numerous before, but today it is considered a vulnerable species. The main threat is poaching, since in the countries of South and South-East Asia its meat is eaten, despite the ban on fishing. Catching such a huge and slow fish is as easy as shelling pears: sometimes it’s enough just to swim up to it and insert a hook into its mouth, although much more often fishermen use a harpoon or nets.
Wherein natural increase progresses very slowly, as whale sharks begin to reproduce at the age of 30 and sometimes 35 years, when their body length reaches 8-9 meters. This is an ovoviviparous species, meaning the embryos hatch from egg capsules directly inside the mother's womb. One female is capable of giving birth to from one to 10-15 babies about 60 cm long.
nationalgeographic.com
Little sharks can go without food for the first two weeks. They grow very quickly, sometimes by 1 cm per day. This is a kind of defensive reaction, because big sizes give them a better chance of surviving in the ocean among predators. They are often attacked by blue sharks and sharks, but adult sharks have no enemies. Still: the thickness of their skin is 10-14 cm - reliable protection from the teeth of any predator.
Whale sharks are extremely slow - in normal conditions their speed rarely exceeds 5 km/h. During feeding, the fish may even stop in one place, smoothly swaying up and down and moving its head from side to side. The shark eats everything it can swallow. Most often these are small crustaceans, jellyfish, squid, anchovies, sardines and other schooling fish, which it sucks in along with water and then filters, releasing the water through the gill openings.
The whale shark has several thousand teeth, but they are all small (up to 6 mm in length) and are needed not to bite prey, but to hold it in the mouth. From the huge mouth, filtered microorganisms enter the stomach through a narrow 10-centimeter esophagus. The shark eats a lot and for a long time. Sometimes it takes her up to 7.5 hours to feed, and in an hour she can swallow from one and a half to three kilograms of prey.
In the mid-19th century, the whale shark had a reputation as a man-eater. Of course, this is far from true. In fact, she is so kind and peaceful that she often even plays with the swimmers. This is why divers love meeting her so much. Many tourists go to the Maldives, Seychelles or to the Red Sea just to meet this unique fish.
The ancestors of modern sharks (Heterodontidae) appeared in the World Ocean about 350 million years ago. years ago, when the continents and oceans had not yet acquired their modern shape. Sharks have no bones - their skeleton consists almost entirely of cartilage. The gill cheeks of sharks are not covered by gill covers. And most importantly, sharks, like everyone else, cartilaginous fish, no swim bladder. In order not to sink to the bottom, the shark constantly moves. The shark must swim continuously so that its gills are constantly washed with fresh water. Triangular teeth are arranged in 5-6 rows. The back teeth replace the front teeth as they wear down. In 10 years, a shark can carry up to 24 thousand. teeth. The jaw compression force reaches 18 tons.
The whale shark is listed in the Guinness Book of Records 1999 as the largest fish on earth.
Whale shark for a long time was known only to sailors sailing in tropical seas. Their stories, which, however, were richly decorated with fiction, contributed greatly to the wide dissemination of tales about sea monsters.
The first specimen examined by scientists was caught with a harpoon in Table Bay (South Africa) in 1828. In total, about 100 specimens were studied. Since then, these sharks have been seen many times, but they have rarely fallen into the hands of researchers, which can be explained by their large size and the difficulty of delivering them to scientific institutions. The largest officially recorded fish was caught near Lake Baba near the city of Karachi (Pakistan), in November 1949. Its length was 16.25 m, the girth of the body at its widest point was 7 m. The mass was 15 tons. Despite its size, the whale shark does not represent great danger for humans, although there have been cases when these fish pierced boats, mistaking them for a rival. Field observations prove that sharks can be larger. The smallest specimen ever caught was 1.8m long.
The whale shark's head is blunt, as if flattened from top to bottom, like that of a catfish. She has a powerful, heavy body, a relatively small head with tiny eyes and very large gill slits. Longitudinal ridges run along the sides. The caudal fin has a semilunar shape, and its axis is sharply turned upward. The dark gray or brown body is dotted with numerous white or yellowish spots. Mouth from ear to ear, or rather from eye to eye. The mouth is wide, full of teeth: 15 thousand! But all are small. They serve not for biting, but for “locking” food in the mouth. Whale sharks eat only small planktonic animals - crustaceans, small fish and squid. She eats relatively little, 100, sometimes 200 kg per day. And that's not always the case. She usually eats this portion in 2-3 days. They don’t need to eat every day at all; they know how to store food for future use. The shark has a special “bag” in its stomach, something like a spare stomach. She will catch something and, if she is full, sends the prey into a bag, where the food can remain and not spoil for 10-20 days, even a month. Why? Nobody knows.
Moving slowly with its mouth wide open, the whale shark collects oral cavity every little edible thing. When the shark closes its mouth, water is filtered through the gill openings. Then the filtered food organisms enter the stomach through a narrow esophagus. If a shark has not eaten anything for a long time, then it attacks everything that comes in its way without understanding. That is why a variety of inedible things were sometimes found in the stomachs of caught sharks: rubber boots, bottles, coconuts, apples, flowers.
Whale sharks are called southern because they live only in the warm waters of the tropics and subtropics. They have not been found in the Mediterranean Sea. These sharks are pelagic and are observed in the surface layers of water. Well-fed whale sharks swim lazily near the surface, sometimes in large flocks. They love to stand in the water like soldiers. Then, as the wave runs away, their heads are visible in the gap behind it, looking like barrels from a distance. They love to lie spread out at the very surface. Sometimes at night, and even during the day, ships come across whale sharks. As a result, damage occurs on both sides.
One such incident occurred in 1905. A passenger ship sailing to India rammed a whale shark about 17 m long, dragging it in front of it on the stem for 15 seconds. As newspapers of the time reported, passengers who had little knowledge of ichthyology decided to give the monster the “scientific” name PiscisRudyardensis - “Rudyard’s fish”, in honor of the famous English writer Rudyard Kipling.
The northern whale shark, or basking shark, is smaller than the southern one, its record length is 15 m (as far as is known). A ten-meter one weighs 4-7 tons. she also has the habit of “dozing” at the surface of the water, with her fin, sometimes her tail, and less often her snout, sticking out of the water with her back. For this, the British call her “basking” (“basking in the sun”, “blissful”). The epithet “northern” is earned by it for its attachment to relatively cool waters and moderately warm waters. North of the tropical Atlantic, these sharks swim to Greenland, Iceland (sometimes to the White Sea). In the Pacific Ocean to southern Alaska. These are their summer visits.
In winter, giant sharks leave these places, where they grazed on the plankton “fields” that are depleted by autumn, but not to the south, apparently, into... the gloomy depths. There the sharks seem to have nothing to feed on at all. They go into a kind of hibernation. They do not eat anything, they live on reserves of fat stored in the liver. The gill rakers of the filter atrophy as unnecessary. Only by next spring they grow again. In a drowsy stupor, they barely sway their tails, for months, plunging into the darkness of the depths and dreams. In the spring, sharks awaken, their gigantic shadows slowly slide higher and higher towards the light, where the Baskings blissfully summer days.
Here, near the surface, they have weddings in the spring. Then 2 years, perhaps longer - pregnancy. And the sharks again, apparently, are moving into the depths. Childbirth also takes place there. Their eggs or, as they are also called, eggs are very large, the shell is hard, chitinous, dark brown, almost black. They are not round, but quadrangular and the size of the pillow on which they sleep. The length of each egg is 63cm and the width is 40cm. Each egg has tails at the corners - long and strong chitinous strands. They attach the eggs to seabed and corals, stones, algae. The shark will “carry” 10-20 of these eggs, “tie” them to the rocks on the seabed and swim away. Forever. The mother shark will never remember them again and will not take care of her little sharks. One and a half meters, presumably, in the baby shark that saw the light for the first time, however, in the land of darkness where he was born, there is no light. How many years will he live and grow to be comparable to the gigantic fish that gave birth to him? How much plankton do you need to strain from the sea to get 4-7 tons? No one knows this yet.
The shark does not distinguish color; In addition, she is “hard of hearing.” But she has a very subtle sense of smell and a well-developed lateral line, thanks to which she picks up the smallest fluctuations in water at a distance of up to 300m.
The whale shark is not shy and very peaceful. The scuba divers came close to her more than once, touched her body with their hands and even tried to straddle her.
One day such an incident happened. The German scientist Hans Hass and his comrades were working on a research vessel, and suddenly a huge whale shark appeared near them. The scientists quickly put on scuba gear and jumped into the water. At first they were afraid to swim close to the shark, but the shark behaved peacefully and did not pay attention to the people at all. Then they swam closer, began to stroke her, two grabbed her by the tail. The shark looked at the scientists and made no attempt to attack them. Then one of the scuba divers became completely bold: he sat astride the shark and, holding the fin, swam. The shark no longer liked this, but she did not throw off the annoying rider and did not express her displeasure in any way, but began to slowly dive. The rider had no choice but to leave his huge “horse”.
According to scientists, there are now 350-360 species of sharks living on our planet. And not all sharks are known to science. When scientists descended in submersibles to a depth of 5-6 thousand meters or more, they saw deep-sea sharks that had never been in human hands before. Maybe these are ancient sharks, familiar to us from fossil remains, and their distant descendants still live on great depths The world's oceans, or maybe these are new species. Who knows?
Used Books.
“Animal Life”, volume 4, Moscow “Enlightenment” 1983.
Encyclopedia for children, 2 volume, Biology, Moscow “Avanta+” 1998.
“Guinness Book of Records 1999”, “ast”
Domain: Eukaryotes
Kingdom: Animals
Type: Chordata
Class: Cartilaginous fish
Squad: Wobbegong-like
Family: Whale sharks (Rhincodontidae Müller et Henle, 1839)
Genus: Whale sharks (Rhincodon Smith, 1829)
View: Whale shark
Range, habitats
To represent their habitat, it is important to understand that whale sharks live in places where food is concentrated for survival. They are also heat-loving animals, preferably choosing areas with water heated to 21-25 °C.
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.
First scientific description
Zoologists first learned what a whale shark looks like in 1828. At that time, Andrew Smith, an English naturalist, was working in South Africa. 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 Atlantic Ocean.
Smith did detailed description this fish, new to science, and gave it 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, like long ridges, stretch to the tail.
- Large pectoral fins(up to 2.4 m long).
And here’s what a whale shark looks like through the eyes of the famous traveler Thor Heyerdahl from the book “Kon-Tiki”:
“The head belonged to a gigantic monster, and it was so huge, so terrible that the sea serpent itself, if it had appeared before us, could not have struck us more powerfully. 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.
If you look at 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 scientific observation behind this view.
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 specimens. It is covered with the usual “skin teeth” for all sharks - 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.
Behavior
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 tagging data, can descend to a depth of 700 m, where the water temperature is about 7 °C. Whale sharks swim using wave-like movements throughout back body, and 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 often, 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 the sharks are gathering in large groups in these places every year in August - they are attracted a large number of freshly caviar mackerel fish, which sharks readily eat. Such concentrations of whale sharks have never been observed in other areas of the ocean.
Nutrition
The way whale sharks feed is somewhat different from the way basking sharks gather food. Whale sharks can suck water into their mouths using a huge “cheek” pump, closing their gill slits. The water is then filtered and removed through a sieve of the dental and gill apparatus. Therefore, the diet of whale sharks often includes not only helpless plankton, unable to move independently, but also larger prey - even small fish and marine invertebrates (shrimp, small cephalopods, etc.). The giant shark, unlike the whale shark, passively plows the sea, collecting everything that comes in the way of this kind of trawl into a huge bag-mouth, and separating food from the water with gill rakers.
An adult whale shark can “process” up to six thousand cubic meters of sea water in an hour, extracting food from it. Well, how rich the water is in food, you can judge by the fact that the stomach of these fish can hold up to 0.3 cubic meters. m of tiny prey. The shark uses part of this catch to maintain the energy balance in the body, part is stored “in reserve” in a special section of the stomach, and part is stored in the liver of this fish for the darkest day.
However, the size of the liver of whale sharks is relatively small, so using it as a kind of “float” to support a massive body in the water is not effective. These sharks use a technique characteristic of some species to increase body buoyancy sand sharks– she is swallowed into the stomach required amount air and release it when diving into depth.
Reproduction
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 in Texas, at a depth of 57 m, a similar capsule was discovered. It contained a whale shark embryo, easily identified due to its characteristic coloring - white spots and stripes on 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, about half a meter. They have significant internal reserves of nutrients, allowing them to go without food for a long time. external source stern. 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, where the largest in Western Australia is located marine reserve) revealed that females apparently 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, in 95% of males, sexual maturity occurs upon reaching 9 meters in length.
Natural enemies
Even the size of a whale shark in itself categorically excludes the presence natural enemies. This species has well-developed muscles, thanks to the constant movement that is vital for it. It almost continuously wanders through the expanses of water, developing a leisurely speed not exceeding 5 km/h. At the same time, nature has a mechanism in the shark’s body that allows it to cope with the lack of oxygen in the water. To save its own vital resources, the animal deactivates part of its brain and goes into hibernation. Another fun fact– whale sharks do not feel pain. Their body produces a special substance that blocks unpleasant sensations.
Whale shark and man
Whale shark as a commercial object
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 (that is, when the whale shark was somewhat more numerous than now) emphasized that it commercial value very little everywhere. The usual method of catching these sharks is the same as for hunting whales - using 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 with set nets, although often the whale shark is caught as bycatch in nets set for other fish. In 1995, Taiwanese fishermen harvested approximately 250–272 sharks, of which 158 were killed using hand harpoons and the rest were caught using nets.
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, meat giant shark. The young shark mentioned above weighing 1,700 kg, caught by the Indians near Tuticorin, was sold for 1,200 rupees, that is, about $30. In February 2012, a very large whale shark with a length of at least 12 m was caught near Karachi; She was caught by fishermen, apparently already dead. The fish was sold for 1.7 million Pakistani rupees (over 18 thousand dollars)
Currently, products obtained from whale sharks can still be found on legal sale. Thus, in Hong Kong in 2010, there were cases of trade in dried whale shark fins at a price of about $300 per piece, used to prepare a gourmet 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.
Danger to humans
A whale shark allows divers to get close to it (photo taken off the coast of Cancun, Mexico)
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. 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.”
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.
First famous case The keeping of whale sharks in captivity dates back to 1934. However, at that time the whale shark was placed not in an aquarium, but in a fenced-off area of the sea bay in Japan. This specimen lived for 122 days. In Japan they were generally kept in captivity greatest number whale sharks - 16 heads (14 males and 2 females) from 1980 to 1996. The Churaumi Aquarium in Okinawa currently houses the largest whale shark in captivity - a 4.6 m long male was introduced into the aquarium in 1995 and has since grown to 7 m. All sharks housed in Japanese aquariums , were caught near Okinawa. The sharks are kept in water at a temperature of 19–29 °C and fed a mixture of krill, small squid and small fish. A 60 cm long newborn baby shark kept in an aquarium was fed planktonic shrimp Acetes intermedius.
A number of other large aquariums also have experience keeping whale sharks. In 2007, two whale sharks were placed at the Georgia Aquarium in Atlanta. Both fish, caught near Taiwan, measuring 3.7 and 4.6 m in length respectively, were flown in in 2007; transportation was carried out in 6-meter tanks with oxygen supply. Both fish are placed in an aquarium with a capacity of 23,845 m³. The previous shark, kept in Atlanta, died in early 2007 from inflammation internal organs, having lived in this aquarium for less than two years.
Twice sharks placed in Taiwan aquariums died after a short time, but in 2005 the efforts of Taiwanese scientists were crowned with success. There are currently two sharks kept in Taiwan, one of which, a 4.2-meter female, has no dorsal fin, apparently cut off by fishermen or bitten off big shark. A 4-meter whale shark is available in the Dubai Aquarium, where it has been kept since the summer of 2008 in an aquarium with a capacity of 11 thousand m³. This shark is fed krill, which consists of euphausian crustaceans, meaning it gets the same food that it eats baleen whales. In the southern Indian city of Thiruvananthapuram, a very young whale shark, about 95 cm long, died almost immediately after being placed in an aquarium in 2002.
Is it listed in the Red Book?
The whale shark is one of the most mysterious and little-studied species. Scientists do not have precise quantitative data, but it is reliably known that these underwater inhabitants not much. In 2000 the taxon was assigned protective status"in a vulnerable position." The most serious threat to the species remains active fishing in South and Southeast Asia, where local fishermen annually catch huge number whale sharks, the population decreases by 5–6%. Here, meat of this species is a component of many dishes. national cuisine, so the fight against poaching turns out to be ineffective.
Back in the mid-1990s. Many countries, including the Maldives, Philippines, Mexico, Thailand, Belize, and India, have introduced a ban on the fishing of whale sharks.
- The maximum body length of a whale shark, according to various sources, varies from 14 to 20 meters, while such a giant can weigh about 30 tons. But even the largest individuals are far from the size blue whale, whose weight reaches 150 tons.
- In view of their impressive size, the question often arises, how many teeth does a whale shark have? She has a lot of teeth, about 300,000, but the length of each of them does not exceed 5 mm, and they are not intended for biting, but not to release swallowed food.
- The whale shark eats exclusively small and very small marine life - plankton and small fish. In view of this, we hasten to dispel another myth - the whale shark is absolutely not dangerous to humans, and in general, it does not even pay attention to people swimming nearby and does not attack.
Video
Sources
http://web-zoopark.ru/ribi/akula_kitovaya_rhincodon_typus.html https://rybkivse.ru/hryaschevye/pro-kitovyh-akul-interesnoe.html http://scharks.ru/vidy/kitov/index.shtm
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 great variety the size of this animal species.
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 give you a little ride, but do not forget that with a blow from their tail, these giants can injure and even kill. 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 marine life: 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. Great amount 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 the Pacific Ocean and waters 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. During 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. 
The whale shark was first described by Andrew Smith in 1828, based on a specimen harpooned off the coast of South Africa. Historically, there have been many different names (alternative scientific names) for family, genus and species.
The genus of sharks is now named Rhincodon typus.
Geographical distribution
The whale shark has a very wide distribution range - in all tropical and temperate warm seas, with the exception of Mediterranean Sea. Distributed throughout the Atlantic Ocean, from the Caribbean to the coast of central Brazil and from Senegal to the Gulf of Guinea. It is also found in Indian Ocean, including the Red Sea and the Persian Gulf. In the Pacific Ocean it lives from Japan to Australia, from Hawaii to Chile.
Habitat
Unlike most, the shark prefers an open habitat away from the coast. Research shows that this shark prefers warm waters with surface temperatures of around 21-30ºC, with a high density of plankton.
The whale shark is thought to be migratory, but there is currently no direct evidence to support this hypothesis. Its movements may be associated with the presence of a nutrient medium.
Whale sharks can undertake either fairly localized or large-scale transoceanic migrations.
Every March and April, whale sharks are known to concentrate on the continental shelf of Australia's central and western coasts, particularly in the Ningaloo Reef area.
Whale sharks have been observed near La Paz, Mexico. The researchers showed that when these sharks fed at the surface, they swam with little or no head movement, gulping and rhythmically opening and closing their gill slits.
Biology of the whale shark
Distinctive features
A streamlined body and a flattened head characterize the whale shark. The mouth is transverse, very large and almost at the tip of the muzzle. The gill slits are very large. The first dorsal fin is significantly larger than the second dorsal fin.
The whale shark has a "checkerboard" color pattern of light spots and stripes on a dark background.
Whale sharks are greyish, bluish or brownish in color, with spots. The belly is white.
One theory for shark coloration is that pigment spots may be an adaptation for radiation protection in species that may spend a significant amount of their time in surface waters and be exposed to high levels ultraviolet radiation.
Teeth do not appear to play any role in nutrition.
Longitudinal protrusions appear on the body along the length of the body; perhaps they are intended to play some role in controlled movement.
The whale shark is the largest living fish. Maximum size 20 m. The smallest adult specimen was found 55 cm in length. Puberty in both sexes occurs after 9 months. It is believed that the whale shark lives on average 60 years.
Whale sharks feed on plankton and nekton, including small crustaceans, schooling fish, and sometimes tuna and squid.
The whale shark feeds actively with its mouth open. By closing its mouth, it releases water through its gills.
During the short delay between the closing of the mouth and the opening of the gill flaps, plankton may become trapped in the dermal denticles lining the gill plates and pharynx.
The fine sieve, a unique modification of the gill rakers, forms a barrier to the passage of all but liquid, retaining for nutrition all organisms over 2 to 3 mm in diameter. Almost nothing except water passes through this sieve.
Coughing has been observed in whale sharks, a mechanism believed to be used to clear or flush out the accumulation of food particles from the gill rakers.
Whale sharks move their heads from side to side, vacuuming sea water, rich in plankton.
The whale shark's small eyes are located on the sides of its head. Because of this, vision may play a much smaller role than smell.
The whale shark is ovoviviparous.
In the past, the whale shark had little interest in humans. Currently, commercial fishing for whale sharks is limited, but the ban may be reduced as demand for food increases.
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