Frilled shark - a living fossil (16 photos + video)

The frilled shark is a dangerous creature that comes from the Cretaceous period. This predator occupies one of the first places in the ranking of the most interesting fish.
Unlike other species, it has not evolved during its existence. And that is why it is called a living fossil.




This ancient animal got its name for the serpentine shape of a long, almost 2-meter brown body and the folded skin covering the gill openings. The webbing of the gills, intersecting at the throat, forms a wide sac of skin that resembles a cloak. This species does not have eyelids, and the spine does not divide into vertebrae, which once again proves the primitiveness of frilled fish. All fins are located side by side, and the caudal fin consists of only one blade. The mouth of the cloak-bearer is his own pride. Firstly, the mouth is located not on the lower part of the snout, but on its final part. The teeth are hooked, five-pointed, comb-shaped, a little like a crown, and are located in an uncharacteristic sequence for sharks - small in front, and larger in the back. In total, there are about 300 sharp teeth in the jaw. In appearance, these sharks look more like an eel or a sea snake than ordinary sharks.



This species of shark was described in 1884 by the American zoologist Samuel Garman. The name Chlamydoselachus anguineus comes from the ancient Greek χλαμύς - "cloak" and σέλαχος - "shark" and the Latin anguineus - "snake-like". For a long time, this shark was considered a single species of its family and genus. Then, a second species was added in 2009, Chlamydoselachus africana. The prehistoric monster prefers the warm waters of the Atlantic Ocean, the tropics, but have been seen in the Barents Sea and near Norway. Only very recently has information been obtained that this species is capable of vertical migrations - when the temperature changes or there is a lack of food, the chimera fish approaches the surface.



This ancient animal has two main names - the frilled shark, which it received for the presence of a peculiar brown plancet on the body, which resembles a cloak. The second name is the corrugated shark. It owes this name to the numerous folds of skin on the body. Such peculiar folds on its skin, according to scientists, are a reserve of body volume to accommodate large prey in the stomach. After all, the frilled shark swallows its prey mainly whole, since the needle-like, inward-curved tips of its teeth are not able to crush and grind food. But they perfectly hold slippery prey in their mouths and do not allow it to escape from their mouths. The frilled shark lives in the bottom layer of water of all oceans, except the Arctic. Very rarely, individuals are found at a depth of less than 200 meters - this is a typical deep-sea predator. Perhaps it has survived to this day only because it has no worthy rivals and enemies in the depths of the ocean. The frilled beard attacks by shrinking, and then sharply shooting its whole body, like a snake, and its long jaws with leather folds allow it to capture the entire prey. Frilled sharks can swallow prey half their length. In addition, they create negative pressure by closing the gills, and suck unlucky victims directly into the belly. The found bodies of serpentine predators did not make it possible to identify the contents of the stomach, which indicates either long intervals between meals, or a rapid pace of digestion.







It feeds on cephalopods and fish. Based on the study of the stomach contents of the caught frilled sharks, scientists concluded that squids make up almost 60% of the diet of these predators. Moreover, they swallow these cephalopods whole. And once in the stomach of a frilled shark they even found the remains of a cat shark, the length of which was 40% of the length of the body of the predator that swallowed it. The gill bridges almost close at the throat of the shark, forming a wide collar resembling a kind of toad. There are no nictitating membranes in frilled sharks. An interesting feature that proves the primitiveness of these selachians (or, as they are also called, clamidoselachians) is the open lateral line. The receptors are located on its skin in a special groove and are not covered with a gelatinous liquid, as in other fish, interacting directly with the environment. The fins of the frilled beards are strongly shifted back, except for the pectoral fins. There is only one dorsal fin, located above the fin. Caudal fin with atrophied lower lobe and well-developed upper lobe. Frilled shark viviparous. Pregnancy of females lasts about 2 years, with a recorded maximum of up to 3.5 years, and then 2-3 independent eel-like cubs are born. The gestation period in this species is the longest of all vertebrates. A newborn baby shark of a prehistoric shark is about 50 cm long. But even now, relict crumbs do not give up their right to leadership in the world's oceans - it is difficult to find an animal stronger and more powerful than the frilled shark.



This species has not been sufficiently studied. Only a few cases have been recorded when the cloak-bearer was taken out of the water alive. The last of them was in 2007, when Japanese researchers were lucky enough not only to see a monster rising from the depths, but also to film it. Unfortunately, the fish soon died, apparently having some kind of disease. In another case, a frilled shark became interested in the blades of a bathyscaphe cruising on the ocean floor near the Black Continent. She accompanied the underwater car for several hours, and then swam away. The mouth of frilled predators is located not on the bottom of the head, as in all "normal" sharks, but on the tip of the snout. The teeth have a flat base with numerous awl-shaped tips bent inside the mouth of the predator. Usually, each tooth has three longer tips and many smaller ones. In total, the jaws of the frilled coat have from 40 to 57 teeth with such hook-shaped and sharp tips. Another feature of these selachians, which betrays their lag behind actively evolving shark species, is the lower jaw hinged to the skull. For the sake of fairness, it should be noted that the reduced mobility of such a design in frilled beards is more than compensated by the huge size of the jaws, which allow you to "cram" large prey into the esophagus. The eyes of the frilled shark are relatively large, oval-shaped. The uniqueness of this sense organ of the predator lies in the ability to glow in the darkness of the depths, where it spends most of its life. Taken out of the water and killed, a shark quickly loses the shine and greenish glow of its eyes. As befits a polygill, to the glorious order of which the frilled shark belongs, it has six pairs of gill slits. The female frilled shark can reach two meters in length, the male - 170 cm, but the usual size of these fish does not exceed one and a half meters.



More often, frilled coats were caught in moderately warm and warm latitudes. Many cases of capture took place near the Japanese islands, Taiwan, Brazil, Australia and New Zealand. However, there have been cases of catching these amazing fish even higher - even off the coast of the Scandinavian Peninsula, near the coast of Norway. The boundaries of the range of this predator have not been studied, it is quite possible that it can live in the northern seas or near Antarctica. After all, at a considerable depth in tropical seas and, for example, the seas of the Arctic, there is no such difference in water temperature as on the surface. This predator leads a bottom-dwelling lifestyle, preferring depths from 400 to 1500 meters, and feeds mainly on cephalopods, bottom-dwelling bony fish and crustaceans. It will not refuse to diversify the menu with small sharks or rays. It is assumed that Clamidoselachians are able to make vertical diurnal migrations, rising at night closer to the sea surface. During the day, they are located in the depths. They are busy looking for food around the clock, but they are more active at night. Since the fins of this shark do not allow it to develop cruising speeds inherent in, for example, mako, its main attack tactics are similar to those of snakes. The frilled shark seems to shoot its body with its mouth wide open in the direction of the prey and captures it in the trap of its jaws. Before attacking, it can sway for some time in the water column, leaning on the ground with its tail fin. Such movements fascinate and attract the prey closer. They, like many bottom sharks, can use a "cheek" pump to capture food. At the same time, they close the gill slits with peculiar valves and suck the victim or a piece of food into their mouths. The glowing eyes of these sharks are also a good bait for successful hunting.



Many millions of years ago, Clamidoselachians patrolled the deep waters, instilling fear in their inhabitants. But even today, relict sharks do not want to give up their right to leadership in the world's oceans - at a depth of more than half a kilometer, it is difficult to find an animal stronger and more powerful than the frilled shark. For obvious reasons, this species has not been sufficiently studied. Only a few cases have been recorded when cloaks were taken out of the water alive. The last one took place in 2007, when Japanese researchers were lucky enough not only to see a monster rise from the depths, but also to photograph it. Unfortunately, the fish soon died. Perhaps she was forced to rise from the depths to the surface of the sea by illness and a premonition of imminent death. This often happens in the world of aquatic animals - dying krakens also come to the surface - monstrous squids, in the existence of which the scientific world refused to believe for a long time.



In another case, the frilled shark became interested in the blades of a bathyscaphe cruising on the ocean floor near the African continent. She accompanied the deep-sea vehicle for several hours, showing off in front of the windows with scientists clinging to them, and then disappeared into the darkness of the abyss. It should be noted that two species of Clamidoselachia are currently known – the common frilled shark and the South African frilled shark, which was described as a separate species as recently as 2009. South African frilled sharks are found off the coast of South Africa. They were caught in the coastal waters of Namibia, England, and South Africa. They differ from ordinary frilled sharks in a wider head and mouth, proportions in the location of fins on the body. Anatomical differences lie in the number of coils of the spiral valve of the stomach and the number of vertebrae of the axial skeleton. It can be assumed that in the depths of the World Ocean other species of clamidoselachia are also hidden from human eyes. The oceanic "interior" and its inhabitants have been studied much less than we would like.



Today, frilled coats, due to their extraordinary rarity, do not have any commercial value. However, fishermen have suffered from sharp teeth more than once - giant multigill fish simply tear bottom nets set up for shrimp fishing with their teeth. An increase in the number of frilled sharks with humans has recently increased, and researchers say that the reason is not an increase in the number of the latter, but an increase in the temperature of world waters. There is too little air at the bottom, and prehistoric predators simply begin to look for a new comfortable shelter for themselves. Without disappearing or changing in thousands of years, it is likely that frilled sharks will soon regain control of the oceans and will rightfully be considered the most perfect inhabitants of the dark depths of the sea.



So in 2012, a "historical catch" was caught in the net of Murmansk fishermen. Fishermen have pulled out of the waters of the Barents Sea a frilled shark - the only representative of the oldest shark species that has survived to this day.



These fish are not dangerous to humans, and most of them have never seen one.



Cases of catching the frilled shark are known in many areas located in the subtropical and temperate warm-water zones. In the Atlantic Ocean, it was caught off the coasts of Southwest and North Africa and Europe. This shark has also been recorded in the waters of South America, Australia, Japan and California.



Superorder: Sharks Order: Polygill Family: Frilled sharks Genus: Frilled sharks Species: Frilled shark





Source: bigpicture.ru