After 1976, it became clear that there were now not two, but three species of plankton-eating sharks in the world. The first two are also giant sharks, and the third is largemouth shark. What surprised everyone about this fish, I think, is clear from its name. The shark's large head ends in a mouth of incredible size, which opens much wider than that of all other shark species.
The discovery occurred on November 15, 1976, when the US Navy hydrographic ship was conducting its research in the area Hawaiian Islands. On that day, the ship was above a depth of 4,600 meters and therefore could not release a conventional anchor. We decided to lower 2 parachute anchors. After completing the research, when they were picked up, they found in one of them unusual fish huge sizes. It turned out to be a 446-centimeter largemouth shark, whose weight reached 750 kilograms. This giant fish was transferred to the Honolulu Museum.
That's it, for some time there was no more hearing or spirit about this shark. But after 8 years she made herself known again. The second largemouth shark was caught off Santa Catalina Island, California, in November 1984. This copy was sent to the Museum natural history Los Angeles. And then a whole series of similar discoveries began.
Small copy 
Between 1988 and 1990, 4 more sharks were discovered (1 on the coast of Western Australia, 2 on the Pacific coast of Japan and 1 in California), and in 1995, 2 more specimens (near Brazil and Senegal). And so on until 2004. In total, about 25 specimens were observed between November 1976 and November 2004, the largest of which was a shark found dead in April 2004 on the shore near the city of Ichihara in Tokyo Bay. Its length was 5.63 meters. It was a female. The smallest shark was a male, caught on March 13, 2004 near the island. Sumatra. Its length was 1.77 meters. Another specimen was caught by Philippine fishermen in 2005.
The largest specimen 
The smallest specimen The most outstanding part of this shark's body is its incredibly large mouth. The color is not much different from other types of sharks - dark gray or dark brown. The belly is much lighter than the back.
Gray color Since all sharks belong to the class cartilaginous fish, then she was no exception. The largemouth skeleton consists of soft cartilage, and the tissues are highly saturated with water. As a result of this, the shark is not able to develop decent speeds when swimming, so its approximate speed is only about 2 km/h.
At the very beginning of the note, we already mentioned the specifics of her diet. The main food of the largemouth shark is plankton (crustaceans, jellyfish, etc.), of which special preference is given to reddish euphausiid crustaceans, also known as krill, that live at shallow depths. A largemouth shark, having stumbled upon a school of krill, opens its mouth and sucks in a large volume of water and, pressing its tongue to the palate, squeezes the water out through closely spaced gill slits. The krill's escape route is blocked by numerous small teeth. After straining the water, the shark swallows everything that remains in its mouth.
Huge mouth with numerous small teeth 
Open mouth The largemouth shark is a pelagic fish, that is, it lives in the mesopilagil zone (depth 150-500 meters). At night it rises closer to the surface, and during the day it goes deeper.
This shark lives in the warm latitudes of 3 oceans: the Atlantic, Pacific and Indian, but most often it can be found off the coast of California and Japan.
Habitat 
Mating, according to biologists, occurs in the fall off the coast of California, because that is where the most mature males were found. Like many other sharks, the greatmouth shark is ovoviviparous.
The basking shark or largemouth shark is one of the mysterious creatures ocean. The sensational discovery of this species occurred relatively recently, in 1976, and to this day it remains the only one in the Megachasmidae family.
These fish are now considered the rarest in the world.
During all this time, scientists were able to study only 47 individuals, a third of them were alive. The unknown strange animal continues to interest ichthyologists. What extraordinary secrets does the giant big mouth hide?
Why was the shark called largemouth?
Largemouth sharks are huge fish, weighing up to 1.5 tons (judging by the caught specimens). A hefty head with a blunt nose and an open mouth creates a rather intimidating appearance. But, unlike their predatory ocean neighbors, they feed on krill, like basking and whale sharks.
The sea monster's mouth can reach 1 meter in width, with a body length of more than 5 meters.
The skin of the largemouth is gray in color, slightly lighter on the belly.
The habitat of giant largemouth sharks has been little studied, but they have been encountered in the Pacific, Indian and Atlantic Oceans, and they try to stay closer to warm latitudes.
Watch video - Largemouth shark:
Interesting features of the bigmouth shark
The way these fish feed is interesting. The large mouth opens its wide mouth, with thick lips lined with a luminous coating that attracts plankton. A stream of water, along with small unlucky victims, passes through the mouth and exits through the gill slits. However, here gill outgrowths melt in the way of the krill, working like a sieve or filter.
The outgrowths, or “stamens,” are located very often and are up to 15 cm long. The giant largemouth presses its thick tongue to the roof of the mouth, and the water is pushed out, while small crustaceans remain on the stamens. Then the monster pushes the krill into the throat, and skillfully detains the quickest victims trying to get out through the mouth with its small teeth.
This feeding method is typical for whales. However, while whales and other krill eaters passively pass tons of water through their mouths, the largemouth giant is capable of its small prey.
Finding itself in a school of planktonic crustaceans, it makes swallowing movements every 4 minutes.
The teeth of the sea lance are arranged in 23 rows, each of which contains. By the way, it is not clear whether a giant chimera can attack large fish.
What information do scientists have about the shark?
The largemouth's anatomy does not allow it to swim quickly. This slow-moving fish has a soft cartilaginous skeleton. Soft muscles create a watery, flabby sensation. This structure of the shark prevents it from drowning.
By the way, the presence of lips allowed the shark to be called the largest luminous animal in the ocean.
The multi-ton sloth can easily be harmed by aggressive neighbors. Often the clumsy largemouth is attacked by groupers - rock perch. These fish, taking advantage of the slowness of the shark, tear out pieces from the soft carcass, sometimes gnawing it to holes.
In addition, the fat ocean giant can become a tasty morsel for the sperm whale, which swallows the largemouth shark whole.
Afterwards, the mechanisms of its movements were installed on the body of the caught giant largemouth. It turns out that these sharks make daily migrations: during the day they descend to a depth of 120-160 meters, and at night they rise to 23-12 meters.
Moreover, it is interesting that the rise and fall sea bumpkin depend on light levels. Plankton also makes similar migrations, but they are influenced by light, the availability of food, and salt content.
So it’s unlikely that the movements of oceanic lip-slappers are tied to the movements small crustaceans. It’s just that the giant largemouth monsters know at what time and at what depths there is more krill that they love, and they follow the prey.
Watch the video - Meeting of a man and a largemouth shark:
Unsolved secrets of the largemouth predator?
Interestingly, the anatomy of largemouths is more suitable. There is an opinion that these sharks used to be bottom-dwelling, but for unclear reasons they rose to middle waters, and so they became noticed by humans.
Very little is known about the reproduction of sea giants. However, judging by the number of specimens caught near California and Hawaii, it can be assumed that mating takes place there in the fall.
The giant largemouth shark is only gradually revealing its secrets to researchers. Being today the most little-studied fish, every largemouth caught becomes a sensation.
The World Ocean Conservation Foundation has added slow-moving giants to its list. But the defenselessness of these good-natured sharks makes them easy prey for both marine animals and humans.
This rare sea monster was recently caught and eaten by fishermen in the Philippines. The news stunned everyone scientific world, but no action was taken.
Are we really going to lose the ocean giant without really getting to know him? Or will the largemouths again hide under the ocean water and take their secrets down to the bottom?
Mysterious Largemouth
Family Megamouth sharks (Megachasmidae)
Genus: Megamouth sharks (Megachasma)
Largemouth shark
(Megachasma pelagios)
The largemouth shark, or largemouth shark (lat. Megachasma pelagios) is one of the three famous science of plankton-eating shark species (other than whale and giant shark). Since its discovery in 1976, this deep-sea shark has remained the only kind in the family of largemouth sharks (lat. Megachasmidae). No more than three dozen specimens of this amazing and very large fish have been in the hands of scientists.
There is still very little information about the anatomy, lifestyle and distribution range of this shark.
It is impossible to say for sure whether people encountered this species in previous centuries and whether it gave rise to legends about sea monsters, which are a mixture of a whale and a shark.
The first specimen of this shark was caught on November 15, 1976 off the island of Oahu in Hawaii at a depth of 165 meters, after which it was described. It was a 4.46m long male that was caught by an American research vessel after he tried to bite through the cables that were lowered into the water and got stuck in them. The fish were brought ashore because the crew decided that they were interesting material for research.
The animal was carefully studied, and today it is stuffed in the Honolulu Museum.
The second sample was caught in 1984, at a shallow depth (38 m), not far from Santa Catalina Island. It was a male 450 cm long. His stuffed animal is currently on display in the museum.
The third specimen of largemouth washed up in shallow water in 1988. off the coast of Australia - surfers, mistakenly deciding that it was a whale, tried to drag it to the depths in order to save it. The third individual was also a male, 515 cm long.
The fourth and fifth samples were caught in Japan, the fourth - in the winter of 1989, the fifth was caught alive in the net, after which he was released.
The sixth sample caused a real sensation because it was captured alive and scientists were able to study it. On October 21, 1990, scientists near California managed to catch a living male five meters in size. He was caught near Los Angeles and transferred to a research center. It was a five-meter male, who was placed on an ultrasonic transmitter and released. The fish were observed for the next 50 hours. The study results showed that these sharks, like many other species, use vertical migration. The fish spent the daytime at a depth of about 170 m, and at sunset it rose to a depth of about 12 m, and stayed there all night. This vertical migration coincides with the vertical migrations of shrimp, which are part of the largemouth shark's diet.
Largemouth sharks are easily recognized by their huge round head and large mouth located on the front of the head. Inner side The mouth is silvery, the jaws are covered with many small hooked teeth. There are relatively large nostrils on the front side of the snout.
The eyes are round. small. Behind the head are five pairs of long gill slits.
The largemouth shark has two dorsal fin- large anterior, small posterior and long pectoral fins. The ventral and anal fins are smaller. The powerful caudal fin has a heterocercal shape - its upper lobe is much longer than the lower one.
The body coloring is discreet and does not have any spots, stripes or patterns. The color varies from gray to brown or blue-black on the back, and from ashen to pale gray on the belly.
The largest specimen measured was a dead female measuring 563 cm, which washed ashore on April 19, 2004 near the city of Ichihara in Tokyo Bay. The smallest specimen was a male 177 cm long, caught on March 13, 2004 near the island of Sumatra.
Most notable external sign, to which the largemouth shark owes its name, is a relatively large, rounded head with a short nose and a huge mouth. The huge mouth of a fish reveals its food preferences - its design resembles the structure of the mouths of baleen whales, whale sharks and giant sharks. Having collected water into its huge mouth, the predator squeezes it through a sieve of teeth and gill rakers, sending the edible contents into the stomach.
Largemouth sharks were found in the Atlantic, Pacific and Indian Oceans. Apparently, their habitat is very extensive. However, individuals were most often caught off the coast of California and Japan. After analyzing the places where these large marine predators were caught, scientists came to the conclusion that this species is distributed throughout the World Ocean, preferring relatively warm latitudes.
Estimated range of the largemouth shark
Mating appears to take place off the coast of California in the fall, as this is where the largest number of mature male largemouth sharks have been found.
The largemouth reproduces by ovoviviparity; the characteristics of reproduction and the number of cubs in the litter are unknown.
For humans, this species of shark is not dangerous (as are whale or basking sharks), but, like any large animal, this fish should be treated with caution. With a slight movement of its tail, it can seriously injure a swimmer. However, a meeting of a person with this shark in the sea is an unlikely occurrence.
Studies of the stomach contents of dead largemouth sharks have shown that the diet of this fish is based on small organisms - zooplankton, for example, krill. Unlike the basking shark, which only passively filters water containing plankton, the greatmouth shark is able to actively suck in water for filtration. It is still unknown whether these animals also eat small fish. The feeding method of largemouth sharks resembles that of a whale - teeth and gill rakers form a mesh filter that filters plankton, shrimp, crustaceans, animal larvae, and small jellyfish from sea water, which serve as food for the predator.
Megamouth shark stranded on April 20, 2002 off the coast of Nature Valley (33* 59" S, 23* 34" E), in the Western Province South Africa. At first she was mistaken for whale shark, but later it turned out that it was a megamouth shark.
This was the 17th largemouth shark discovered by scientists, dating back to the one caught in the fall of 1976 in Hawaii.
The shark's body was frozen and transported to Port Elizabeth for study by scientists. The shark was well preserved; it turned out to be a female about 4 meters long. After studying and examining the shark's body by scientists, a stuffed animal was made from it for the museum. This is the first largemouth shark discovered off the South African coast, in the west Indian Ocean.
The largemouth shark is quite rare - it lives in sea waters, at a depth of 150 - 1000m. In length, judging by the size of the caught specimens, it can reach 6 meters or more, with males being smaller than females.
The fact that so large creature first discovered in the waters of the World Ocean quite recently, once again speaks of how little we have yet studied our planet and how many more discoveries await us...
IN sea depths such fish as the largemouth shark live. Its habitat covers tropical, subtropical and temperate regions of the World Ocean. Even though the name has the word "shark" in it, this type feeds only on plankton, small fish and jellyfish. The fish swims with an open mouth, which is enormous in size, and obtains food by sucking and filtering water.
These remarkable marine inhabitants became known only in November 1976, when the first such fish was caught near Hawaii. It reached 4.5 meters in length and weighed 750 kg. This find became a sensation in ichthyology of the last century. And her stuffed animal was placed in the Honolulu Museum.
To date, this species has been poorly studied, since it rarely comes into view of people. A little more than a hundred of these sharks were caught, and only a few of them were examined by specialists. The body is black-brown above, the belly is light. The tail has a larger upper lobe and is generally similar to the tails of other shark species.
The muzzle is wide and rounded. The mouth is large with small teeth. It is surrounded by luminous photophores (special glands) that attract plankton and small fish. The mouth of a largemouth shark reaches a width of 1.3 meters. There are 50 rows of teeth in the upper jaw, and 75 in the lower jaw. The gill slits have an elongated shape. The skin is relatively soft. These fish grow up to 5.7 meters in length. Weight reaches 1.2 tons.
Puberty in males occurs at a body length of 4 meters, in females the corresponding value is 5 meters. This species is viviparous. But extremely little is known about reproduction based on the few specimens of both sexes captured.
Largemouth sharks feed at depths of up to 1500 meters. The most optimal depth for them is 120-170 meters. And only occasionally do representatives of the species rise to a depth of 40 meters, and in shallow bays they can even be found at a depth of 5 meters. This makes it clear why they so rarely catch the eye of people.
In the water column, this fish opens its huge mouth wide and swims through the accumulation of krill. From time to time she closes her jaws and squeezes her throat tightly to compact the food. After this, it is swallowed, and the mouth opens again to swallow the next portion of krill. For more efficient hunting, the jaws have the ability to move forward. This allows the fish not to wait for the food to swim into its mouth, but to suck it in.
To study the behavior of this species, a 5-meter largemouth shark was caught in California waters in 1990. A sensor was placed on her body and she was released. He transmitted information about the depth and speed of movement for 2 days. During the daytime it showed a depth of 120-160 meters. At night the fish rose to a depth of 12-25 meters. At the same time, she swam all the time at a speed of 1.5-2.1 km/h. This picture is common for many sea creatures, which track plankton in the water column.
Despite the fact that sharks of this species have large sizes, they do not pose a danger to people. It should also be noted that they are not in commercial demand. Judging by the reviews, their meat is quite edible, but does not have high taste qualities. If this fish accidentally gets caught in the net, it is usually thrown overboard.
The only people who are interested in representatives of the species are ichthyologists, as well as workers of aquariums and museums. There is no information on the number of largemouth sharks.
The pelagic largemouth shark is the only representative of its family, extremely rare view, about whose behavior and habitat very little is known. The largemouth shark is extremely different extraordinary diet, deep-sea habitat and enormous scientific potential. The small number of discovered individuals provided only a small fraction of theses about the peculiarities of the life of this animal; the largemouth shark remains a poorly studied species, but no less interesting.
Where does this name come from?
The largemouth shark, according to the few existing documents, looks like a mixture of a whale and a representative of a shark. Its name is the family in which this animal is sole representative, received for the huge mouth, which is necessary for swallowing masses of water. Such an individual is one of three subspecies that are not active predatory image life. Along with tiger and giant sharks, this animal “weeds out” small crustaceans from the water.
The prefix “pelagic” in the form of these individuals means that they live away from the continental shelf at a depth of over 100 meters. Representatives of this family belong to ocean fish and prefer warm waters, for example, off Hawaii and California. The largemouth shark is extremely rare and is the only representative of its family.
History of species discovery
The first documented evidence of the existence of the pelagic largemouth shark dates back to 1976. Data is extremely scarce, since there are barely 100 individuals of this family in the world. Only a few animals were at the disposal of scientists, the structure of whose organisms became the object of several scientific works dedicated to this subspecies.
The first member of the family was discovered on November 15, 1976 in Hawaii, its length reached 4.46 meters. At first, the animal was mistaken for another representative of sharks - a tiger shark; there are also frequent cases when a large-mouthed shark was confused with a killer whale, since the colors of these two animals are similar.
Features of the structure of the body
The average size of a pelagic largemouth shark is about 4.5 meters, maximum length– 5.7 meters. Body brown, less common gray color, tissues are filled with water, as is the case with other representatives of sharks, skeleton consists of soft cartilage. This representative also needs constant movement, otherwise the individual will simply drown. The teeth are not intended for active predation, the nose is blunt. The fish's temperament is extremely calm and its behavior is slow.
Habitat
Pelagic largemouth shark belongs to the class deep sea fish, its habitat is at a depth of up to 500 meters. However, the maximum recorded depth of habitat for this fish is about 2500 meters. Color and impressive size serve warning for possible predators, since this species of shark does not have sharp teeth for protection. Individuals can migrate to search for food, but prefer tropical and subtropical waters.
The reproductive features of this species are unknown; it is quite logical to assume that this process occurs in a similar way as in the giant shark. Unlike whales, which passively filter water through their baleen, the greatmouth shark makes swallowing movements every few minutes. Whether the fish is capable of hunting is unknown this moment The basis of its diet is considered to be plankton, which consists of small crustaceans and jellyfish.
Habits
Pelagic largemouth shark spends most life in motion. At night, an individual of this species does not dive to more than 15 meters, while during the day it searches for plankton at a depth of more than 150 meters. Migration within waters occurs mainly due to the movement of plankton, which is also characterized by change of location depending on the sleep or wakefulness of predators. Scientists admit that previously the largemouth shark was benthic, that is, it lived in close proximity to the bottom, which was the reason for such a late discovery of the individual by people.
Natural predators and enemies of the largemouth shark
As mentioned above, natural predators the largemouth shark has little, which is primarily due to huge size individuals. However, some types of predators still hunt these animals, namely:
- rock bass;
- sperm whale;
- other sharks.
Predators take advantage of the slowness of this largemouth shark and simply tear out pieces of meat from its body, which is why many animals there are scars on the body. The observed individuals also had marks on their faces from collisions with stingrays and jellyfish. Hardly we're talking about about direct attack, rather about self-defense, as the largemouth swallows huge masses of water in an attempt to filter out the krill.
Largemouth shark: is it dangerous for people?
The pelagic species It is practically harmless to people and can only cause harm to divers who, through carelessness, find themselves in close proximity to the mouth of this giant. Otherwise, the largemouth shark is extremely different calm and good-natured disposition. In turn, the degree of influence anthropogenic factors unknown for this shark species, it is quite possible that this pelagic shark species requires protection.
Heroine of myths and legends
The pelagic largemouth shark could well have become the progenitor of numerous myths about sea monsters, several factors speak about this:
- frightening appearance, including a huge mouth;
- large sizes;
- resemblance to cetaceans;
- living in deep water.
As is the case with giant squid, the pelagic largemouth shark could serve as a basis for the emergence of various myths, dedicated to huge ocean fish that can swallow a ship. This subspecies tries to avoid contact with people.
It is noteworthy that most of the representatives of this family were found already dead. The last recorded case of contact with an individual of this subspecies was in 2015; the discovered remains are highly valued by museums, as they make it possible to study the habits of the largest deep-sea representative of the subspecies. Meanwhile, largemouth sharks become victims not only of attacks by predators, but also of fishing, because their meat is highly valued in several world cuisines.
Some scientists insist that it is necessary to include this individual in the list of species that are on the verge of complete extinction and to ban large-scale shark fishing. However, the data found is not enough to draw a conclusion regarding the current position of the species and the number of individuals. The last recorded number of largemouths was 102 individuals, which is disproportionately low compared to other members of the species.
There is an opinion that largemouth sharks will be among the species that will disappear in the next decade due to anthropogenic water pollution. However, it is too early to draw conclusions about the future of these individuals.
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