Sharks' teeth can change over time. It is now possible to grow a new tooth

If you don't feel like going to the dentist, you are not alone. Most people have concerns about visiting these specialists. One study from the Netherlands even showed that 24% of adults do not just dislike, but are afraid of dentists. In addition, a significant number of people try to avoid visiting such clinics and go there only in cases of emergency. This helps explain why 92% of adults have decay in their permanent teeth.

But there is good news. Recent studies show that we may soon have a chance to fill the cavities in our teeth with healthy living tissue, which will give our permanent teeth a second chance.

How shark teeth grow

It may seem that, compared to other species, people are very unlucky, since we have to be content with one set of teeth for the rest of our adult life. Shark lovers, for example, are familiar with the fact that these animals have unlimited sets of teeth throughout their lives. Some of them have a row of teeth under the skin that are just waiting in the wings to replace the missing ones. In addition, teeth are replaced every three weeks. That is why experts believe that the seabed is littered with shark teeth.

Complex structure

But if sharks, like most reptiles and amphibians, can replace their teeth during life, then why did humans and most mammals receive only two sets of teeth?

The fact is that there is a relationship between the complexity of the teeth and the number of sets that a species has. Since mammals have the ability to chew, they have developed complex sets of teeth of different shapes. For example, pointed canines have only one growth, while premolars have two, and molars have four or five. Such a complex structure of teeth depends on what the mammal feeds on. The species that eat bamboo, for example, have the most complex teeth. For example, the giant panda or bamboo lemur has complex rear teeth with many sharp tubercles that help chew and grind hard tissue. Thus, their teeth look the same even if they are not related to other mammals.

How other animals restore teeth

There are other interesting examples of animals with the ability to repair their teeth. Piranha's teeth are fused together, and they resemble a very sharp knife. Therefore, piranhas lose not one tooth, but an entire quadrant, and they have to rely on the other three quadrants to survive until new ones grow.

Although mammals tend to have two sets of teeth, deciduous and permanent, some have retained the ability to develop more teeth. Manatees, for example, have the ability to develop teeth at the back of their mouth throughout their lives.

Other animals only got one set of teeth, but they are constantly growing. These are rodents such as mice or rats. The secret is that they have stem cells at the base of the tooth that promote dentin and enamel growth. This is necessary because of the solid food they eat.

Evolution in action

It is unlikely that humans will ever develop the ability to have more than two sets of teeth, as evolution requires these differences to affect whether offspring can survive. Nevertheless, we are still developing in this regard - experts say that fewer and fewer people now have wisdom teeth. These are third molars that appear in early adulthood, when our jaw is fully formed. This is because we have been preparing food for ourselves for a long time, and it is softer, so there is no need for third molars. In addition, our jaw is getting smaller, and, accordingly, there is no room for molars. That is why we see more and more people who do not have third molars. Only about 20% of the population does not have wisdom teeth.

The first attempts of scientists

Perhaps we will never have a third set of teeth, but this does not stop scientists from trying to find a way to replace the extracted teeth with new ones, and, moreover, alive. A laboratory at King's College London has successfully implanted bio-teeth in mice. The scientists used human gum tissue and mouse stem cells to grow new teeth from dentin and enamel. One of the problems of using therapy in the human body is that the cultivation of stem cells takes place in a test tube, but there they quickly lose their power.

Nevertheless, science in this matter does not stand still, new methods of growing teeth appear, for which pulp tissue is used, for example, so it is quite possible that after a while new teeth will become available to ordinary people.

Now on the Internet you can find any information, video in a minute, and before I learned all interesting facts from educational programs on TV. I remember there was a channel where they were telling a lot of interesting things about the animal world all day long. I remember very much the eerie shots with sharks, their huge jaws with hundreds of teeth... When we went to the sea with my parents as a child, I was even a little afraid to go into the water, it seemed to me that a shark fin was about to appear. Are sharks really as dangerous as we used to think?

Shark teeth and their features

The open mouth of a shark with a huge number of teeth looks very intimidating. Really, shark is one of the most toothy creatures in the world... The point here is not in their number, although some species of sharks have thousands of teeth, but in the fact that sharks are able to renew them about once a week.

Shark's teeth are arranged in a special way. This is necessary so that her prey could not escape from her mouth in any way. The teeth are arranged in several even rows... Each tooth is directed inward, due to which the shark grips its prey very tightly. Each row may contain about 1000 of these teeth... You will not envy someone who falls into her mouth.

The most toothy shark

There are many types of sharks, and depending on this, each representative has a different number of teeth. The first lines of the rating of sharks with the largest number of teeth are occupied by:

1. Whale shark.
2. Bigmouth shark.
3. Giant shark.
4. Reef shark.
5. Sand tiger shark.

Whale shark surprises not only with its size, but also with the number of teeth that are hidden in its mouth. It was she is in the first place in terms of their number among all akul... Its length can be 15-20 meters, and the weight of this giant fish can reach 20 tons. How many teeth do you think a shark has with this size? In the mouth of this huge shark, you can count up to 15,000 teeth. All of them are built in rows, of which there are approximately 18-20 pieces on each jaw. Impressive? Yeah, it looks very scary. But in fact, with such a huge size and number of teeth, this shark feeds on plankton, various small fish and does not pose a danger to humans... She almost never swims to the shore. She behaves calmly. Some avid scuba divers even had the opportunity to swim very close to the whale shark, take a few photos and even touch this giant creature.

The shark, a bloodthirsty predator, a thunderstorm of the seas and oceans, attacks with lightning speed, knows no pity, is deadly. This short but true characterization applies to only three. Extremely fast and aggressive 4-meter mako shark, brown death. Large length 6-7 meters, the prototype of the monster in the movie "Jaws". And five meters long, the most fearless, capable of attacking even a whale. There are only three sharks from over 400 species. The rest of the sharks are less dangerous due to their slowness, not very aggressive and often just cowardly nature. However, if the shark is hungry, it becomes very dangerous. And if a shark suddenly smelled blood, it instantly wedges and it becomes a killing machine.

The most dangerous sharks are thermophilic, staying closer to the equator. Favorite habitats for the mako and tiger shark are the warm waters of the coastal zone. And the white shark feels great anywhere in the seas and oceans. Sharks, as representatives of the marine fauna, do not have a herd instinct and very rarely gather in schools. They prefer to hunt alone and only during the breeding season begin to communicate with each other. Millions of years of existence - such a long evolution once and for all determined the rules of life for a shark, and it will never become another.

The main and only weapon of a sea predator is teeth, or rather jaws with several rows of teeth. How many rows of teeth a shark has depends on its species. The load on the shark's teeth is unprecedented, it has to grab everything with its teeth indiscriminately, the teeth break, crumble and fall out. Therefore, nature took care of the predator, and the shark has a genetic mechanism for changing teeth. This process is fast, and depends on how many teeth a shark will have in the near future. Cyclic change of teeth about once every two weeks in young individuals and once every two months in old sharks. Moreover, new teeth do not grow in the place of those that have fallen out, but are already at the ready, pressing against the gums. The old teeth are gone, the new row is up and ready to go. Thus, a shark always has several rows of new teeth in stock, and the question of how many teeth a shark has is not an acute issue.

For example, a white shark and a tiger shark always have "mouth full of teeth." In each of 4-6 rows, bent back and pressed, there are up to 300 teeth. There have been several attempts to calculate how many teeth it turns out to have about 15 thousand. The shape of each tooth is also different for different sharks. Classic triangular in a white shark and complex teeth with small notches along the edges in a tiger shark. Some have teeth of an irregular, somewhat abstract shape. From the base to the tip, the tooth bends and becomes thin. Such a tooth will not bite into something hard, but if it clings to any flesh, it will be tight, it will not let go. There are usually fewer such teeth in the mouth of a shark, since they break less often. The task of such a victim's flesh is not to cut or chop it up.

Sometimes, during the hunt, a shark has two or three rows of teeth, but only the front row on both the upper and lower jaw is constantly involved. The jaws and teeth of sharks are a rather complex and at the same time well-oiled system. Nature has given bottom sharks, for example, smaller teeth, but with sharply sharpened edges to make it easier to bite through the shells of crabs and lobster, chitinous shells of crayfish and sea snails. But it is not known how many teeth a shark has, if it lives in the bottom zone, some have more, others have less. Sharks that swim in the upper layers of the body of water, feeding on seals and seals, received naturally long, curved, dagger-like teeth that pierce deep into the victim's body. And mother nature does not limit anyone in the number of teeth, and to the question of how many teeth a shark has, there is only one answer: "as much as you need."

A shark's worst weapon is its teeth. Although there are shark species, such as the giant shark, that do not have them at all. That is why, before answering the question of the species: how many teeth a shark has, you need to decide which shark you are talking about.

The number of teeth in one row of some shark species can reach a thousand. Shark teeth are located on the upper and lower jaws. They are tapered. Shark teeth are evolved placoid scales in origin. Depending on the type of shark, their jaws differ. For example, bottom sharks have hundreds of small, smooth teeth. Their diet usually contains food protected by a hard shell.

Tiger and white sharks are venerable hunters with large triangular teeth. Their edges are serrated, which enhances the bite force. To prevent the victim from escaping from the mouth, the shark's teeth are directed inward. They grow in even rows and are constantly renewed.

Sharp teeth are inherent in pelagic shark species.

They easily penetrate the victim's flesh. So the knife-like teeth of the tiger shark are designed for tearing the meat of large prey. And those sharks that feed on plankton have rudimentary small teeth.

Shark teeth continue to grow throughout life. Despite the fact that the teeth are located on both jaws in several rows, the shark actively uses only the first rows. In this case, the posterior teeth are bent inward.

As we emphasized earlier, different types of sharks do not have the same number of teeth. So the number of teeth in a tiger shark is less than that of a giant and a whale.

At the tiger shark serrated triangular teeth located in 5-6 rows, in total about 280 teeth... Wherein whale shark having small, smooth teeth, has in its mouth about 7 thousand teeth! This is a kind of the most toothy type of record-breaking shark. Giant shark there are about 2 thousand teeth.

This amount is intended to prevent small prey from escaping.

A feature of the shark is a very fast change of teeth. So in about two weeks, a row of teeth can change.

Giant and whale sharks are huge. Their mouths contain a huge number of small teeth. Such sharks do not approach the coast, and therefore cannot harm humans.

Tiger and white sharks are considered very dangerous predators. They lose their teeth every time they hunt. The total number of teeth in the mouth depends on the shape of the tooth, hunting methods and the predator's diet.

Great white sharks have triangular teeth set on a wide base in the jaw. Accordingly, they need much more space in a row than, for example, the needle teeth of a whale shark. White and tiger sharks have about 300 sharp jagged teeth at the edges. They grow in five rows. In young great white sharks, the first row of teeth completely changes once every three months. In older individuals of this species - once every eight months. The older the shark, the less often teeth change.

Despite the huge number of teeth and a fairly quick change, the shark should not lose them just like that. During the hunt, this predator clings to the prey, making lateral movements with its head, and tries to tear off a piece as much as possible. The teeth at this time work like a saw. Not wanting to lose a few teeth, the shark will not pull prey up or down.

A shark needs teeth throughout its life.

The frequent change of teeth occurs due to the fact that the diet of this predator includes large bodies of fish with scales, marine animals with strong bones and a large amount of fat. It is not easy enough to overcome large prey, possessing teeth of the "canning" design. The evolution of all shark species has been going on for over 400 million years. To date, in the entire basin of the world's oceans, it does not have a better design of teeth than these predators.

How many teeth does a shark have?

»Pisces» How many teeth does a shark have?

The shark can rightfully be considered one of the most toothy living creatures on our planet. Moreover, the point is not even the number of teeth - although some sharks (for example, whales) may have up to 12 thousand of them, while others (in particular, giant ones) do not have them at all - but in their amazing ability to easily and quickly recover from any, even the most significant damage.

Experts on these bloodthirsty fish have proven that sharks "change" their teeth more often than some fashionistas of gloves - every week. It is interesting that the shark's teeth are located in its mouth in such a way as to completely exclude the possibility of catching prey out of them: they are directed inward and are located in several even rows, each of which contains up to 1000 teeth. I don’t even want to imagine what a shark victim feels, being in its mouth!

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Tiger sharks have a row of 24 teeth in the upper jaw and a corresponding set of 24 teeth in the lower jaw, for a total of 48 teeth.

Tiger sharks have a square jaw structure and each of their teeth is built using cutting and sawing mechanisms.

The design of the tiger shark's teeth allows it to crush, carve and hold prey in all parts of the jaw. Its teeth also have a feature that allows them to absorb the powerful blow caused by chewing shark food. Without this function, the cutting process would destroy both the tooth and the jaw.

Sand tiger sharks have 44 to 48 upper teeth and 41 to 46 lower teeth, so they can have 85 to 94 teeth. The front teeth are long and serrated and can be seen even when the shark's mouth is closed. Many of the sand tiger shark's teeth are small and located in the back corners of the mouth.

Although these sharks have powerful jaws and many long, sharp teeth, they usually do not attack humans, but prefer to use their teeth to prey on a wide variety of fish. These sharks are constantly losing and developing new teeth. A sand tiger shark goes through about 1,000 teeth a year and up to 30,000 teeth in its lifetime.

Toothy babies.

The question of which shark has the largest teeth will be puzzling for many. Well, of course, the big white one. most readers of the article will think. And they will be right - except for the extinct megalodon. then the absolute record for the size of teeth belongs to this famous predator.

In adults, they can exceed 50 mm in length and are a formidable weapon of reprisal against an enemy or victim.
The teeth of the great white shark are the symbol of all the teeth owned by the predators of our planet. Of course, the tusks of mammoths, elephants and walruses, which have slightly different functions than shark teeth, are not taken into account here.
If we take into account all the "teeth formations" in the mouth of predators, then the record holder for the largest teeth among the animals known on Earth is the narwhal (Monodon monoceros), or as it is more often called, the "sea unicorn". Its tusks (serving more for decoration or intimidation) reach three meters in length.
But in this article we consider the teeth of animals as a tool for killing and butchering prey, so we will not take into account the above-mentioned champions.

If we consider not the absolute, but the relative size of the teeth of sea predators, in comparison with the size of the body of their mistresses, then the great white shark will yield primacy to the tiny (no more than half a meter in length) cigar shark Isistius plutodus of the Dalatian shark family in the order of katraniforms. The Russian name for this predatory baby is the big-toothed cigar shark. The British call it - Largetooth cookiecutter shark, which literally means "big-toothed shark cutting cookies."
Where did such a strange name for a sea inhabitant come from? From what dough can this fish cut cookies in the sea-ocean?

First, let's describe our hero.
The large-toothed cigar shark belongs to the genus Isistius, which combines two more species of cigar sharks - the Brazilian (the most famous) and the very rare South China cigar shark.

The appearance and structure of the body in these relatives are similar, but the large-toothed, in addition to all other minor signs, is distinguished by the largest teeth of the lower jaw. The largest of the large-toothed cigar sharks caught reached a length of only 42 cm. This is a deep-sea predatory fish that rarely (only at night) appears in the surface layers of water, and often forms schools. There are many areas on her body that emit a greenish light in the darkness of the depths. The large eyes of these sharks are also capable of glowing.
Perhaps it is for this property that sharks of the Isistius family are called cigar - their luminous cigar-shaped body, indeed, resembles a smoldering cigar.
But the most unique organ of large-toothed cigar sharks is the teeth of their lower jaw.
They resemble knives in shape - long, with a sharp triangular tip. In the lower jaw of a large-toothed cigar shark, 19 such daggers are densely located, which with their tips form a serrated-shaped cutting edge.

The lower teeth of a large-toothed cigar shark can exceed 5% of their owner's entire body length! If we apply this ratio to a great white shark, then a predator with 5 cm teeth should be a meter long! On the upper jaw of a cigar shark, on the other hand, the teeth are small, with an awl-shaped apex, and have a slight slope.
Why do cigar sharks have such unique and strange teeth?

For hundreds of years, fishermen and scientists have puzzled over the strange wounds present on the bodies of many marine animals. They were surprisingly round in shape, as if someone with a sharp knife carefully cut out pieces of flesh from these unfortunates, along with the skin and meat. The riddle turned out to be intractable, and only in the last century was it solved - it turns out that these wounds are the work of the hands (or teeth) of cigar sharks.
This is how it goes.

The predator cautiously creeps up to its prey, which is played by cetaceans, pinnipeds, sharks, stingrays, large fish, and sticks to their body with its thick lips surrounding the mouth. Then, catching on the victim's skin with small upper teeth, it quickly pierces the flesh with daggers of the lower jaw and begins to rotate its body, literally cutting out a piece from the body of the poor animal.
The whole process takes several seconds, and while the victim is frightenedly trying to understand what happened, the predatory baby is already running away with the prey in its teeth. If a flock of cigar sharks attempt to kill an animal, the victim may well die of wounds. Large animals, after a while, the wounds from the bites of cigar robbers heal, but the scars remain for the rest of their lives.

Most of all, sea inhabitants get it from large-toothed cigar sharks, since the bodies of wounded animals caught are often oval-shaped wounds - a characteristic "seal" of large-toothed Dalatians. Probably, when “cutting off” a piece of prey, they perform lateral movements of the head in combination with rotation of the body, so a perfectly round wound does not work.

According to experts, up to 80% of bites are from large-toothed cigar sharks.

Now you probably understand why these fish are called "sharks slicing cookies." They cut out pieces of flesh with a diameter of up to 5 cm from the body of the victims, in the shape of a round cookie.

It is curious that there are known facts of attacks of these toothy crumbs on swimmers. However, due to the deep-sea lifestyle, meeting a Dalatie shark while practicing water sports and swimming is a unique event.

It depends on what kind of shark

Shark teeth are located in their mouths in rows, sometimes a thousand or more teeth in one row. The teeth are covered with enamel, their shape is subulate or triangular, with a sharp cutting edge or subulate serrated. It is believed that behind each tooth in "active service" there are several more teeth in reserve. As soon as one of the teeth wears out or is lost, another takes its place.

Shark teeth are the largest in the fish kingdom. The shape of the teeth varies from species to species, from jaw to jaw, and even from their location on the jaw. So, in a sixgill shark, the teeth of the upper jaw are different from those of the lower, and the front teeth are not similar to the rear ones. But in most sharks, the teeth are of the same type and are an essential reliable sign for the separation of local groups. The number of teeth in different shark species is not the same. If the teeth are in the form of jagged triangles, then there are fewer of them than the small smooth teeth in other shark species. A tiger shark has 280 teeth in 5 - 6 rows. Out of 5 - 6 rows, only 1 - 2 are functional, and the rest are spare.

The most terrible jaws, without exaggeration, are sharks.

The structure of the jaw of a predator depends on the lifestyle and food consumed.

Using these teeth, scientists tried to reconstruct the jaws and they got a layout in which a small passenger car could easily fit.

Bizarre shark jaws

Shark jaws and teeth have evolved into very strange shapes. So, for example, in the Carboniferous period there were predators, the lower jaw of which was very long and coiled into a spiral. The teeth of these cartilaginous fish (helicoprions) were connected by bases.

Why nature created such a strange jaw is still a mystery to scientists.

Watch the video - How the Helikopryon shark jaw worked:

One of the assumptions put forward by the researchers was the following: Helicoprions (Latin Helicoprion) fed on small cephalopods and other molluscs hiding in the sand. And in order to get them, the ancestors of modern sharks "plowed" the bottom with their jaw, like a plow.

Helicopryons reached a length of 12 meters, so one can imagine what furrows they left on the seabed.

The Triassic also created a branch of sharks, now no longer existing. These sharks ate hard-shelled invertebrates. To cope with such a shell, sharks "got" their jaws,.

Thriving in the Mesozoic era, over time, they lost their leading positions among cartilaginous fish.

An important role, apparently, was played by the structure of the jaws. In the hybodont, the upper jaw was fixedly attached to the skull, while in all modern species of sharks, both jaws are movable and able to move forward.

Watch the video - Retractable shark jaws:

How the goblin shark jaws work:

Accordingly, the number of fish caught with such jaws is greater than what the hibodus could catch. After all, not only can the jaws of modern sharks be extended, but also their structure is such that these predators are able to attack from any angle. And the compressive force in some species of sharks reaches a ton (in a great white shark - up to 2 tons)!

Evolution leaves the most adapted species, therefore, sharks, accordingly, acquired the shape and size that we have the honor to observe in our time.

Watch the video - Types of jaws of various sharks: