Nowadays on the Internet you can find any information or video in a minute, but before I learned all the interesting facts from educational programs on TV. I remember there was a channel where they told a lot of interesting things about the animal world for days on end. I really remember the creepy footage from 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’s fin was about to appear. Are sharks really as dangerous as we used to think?
Shark jaw, teeth, dentition: how many, how are they arranged and why?
The most important part of a shark's jaw is, of course, the teeth. The shark's teeth are arranged in two rows. Why? The reason is that sharks constantly use their teeth to hunt and crush food. Shark teeth are weapons of attack and defense. Therefore, over the course of its entire life, a shark can lose all its teeth. This is due to the fact that they are weakly attached to the jaw.
Unlike humans, they do not have roots to support them in their depression. Because of this, when a shark bites into meat, the tooth may remain inside the prey due to the stiffness of the fibers. Therefore, the second row of teeth plays the role of spare teeth. If the shark runs out of teeth on the first row, it will be able to use the second and third.
Important fact: a shark's ability to lose its teeth is also a means of self-defense. When a shark hunts, it opens its mouth wide and bites its prey. During this process, a piece of prey may occupy the entire mouth, and the shark will not be able to breathe. And she breathes by swallowing water and extracting oxygen from it. In this case, it is easier for the shark to separate several teeth from the front jaw, release the prey and then attack again. Otherwise, she may lose access to oxygen.
Don't forget about shark diseases, which also damage teeth and lead to their loss. Sharks also have plaque on their teeth that causes caries or tartar. This problem that sharks face is very similar to what happens to human teeth.
Also, the way a shark's teeth are positioned has a direct connection with how oxygen gets inside the shark's lungs. The breathing process of a shark occurs as follows: the shark opens its mouth, water enters it. After this, oxygen is supplied to the shark's lungs through the gills. For this reason, the shark’s mouth should not be completely closed the entire time it is in the water. And the teeth grow so that it is more convenient for the shark to swallow water and extract oxygen from it.
Population and species status
According to experts, about 25 percent of all shark species are on the verge of extinction, while the total number of sharks is decreasing day by day, and at a rapid rate.
Most of the negative factors affecting shark populations in one way or another are associated with anthropogenic factors, such as:
- A decrease in the number of animals included in the diet of sharks, which is associated with human activity.
- Pollution of the world's oceans with waste, especially plastic, which is also associated with humans.
- There is constant fishing, including illegal ones, and people are also involved here.
- Low regenerative abilities of the species.
They often become victims of their insatiable appetite, as a result of which they swallow everything that comes their way. Fish especially suffer from plastic, which is very resistant to the gastric juice of a shark, which even digests metal. As a result, the shark dies.
How does a shark's jaw work - the structure of a shark's jaw
All sharks existing on earth today have the same jaw structure. Therefore, if you know how the jaw of one species of shark works, you can confidently say that the jaw of another species of shark works as well.
Diagram of the structure of a shark's jaw
Main parts of a shark's jaw:
- Pay attention to the facial, anterior part of the skull (scientifically “visceral”). The jaw arch is attached to it (another name is the “visceral arch”). It consists of two main parts: the palatoquadrate cartilage and the Meckel's cartilage. Ligaments hold, fasten together these two components of the ligament.
- The first cartilage is called palatoquadrate due to its shape and location. It replaces the upper jaw, and the lower cartilage, called Meckel's cartilage, does what the lower jaw does.
- Behind the first arch you will find the hyoid. Its components are three cartilages: one of them is in single quantity, and the other two duplicate each other.
- The first cartilage, the one that does not have a double, is called by scientists the hyomandibular, or pendulosa for short. It moves easily from side to side and is directly attached to the skull in the area of the auditory region using ligaments. At the other, opposite end of the suspension there is a maxillary arch and a hyoid, a paired section of the hyoid arch. How are the hyodes attached to each other? Correct answer: they are attached to each other using cartilage. Also, this same cartilage is attached to the tongue of the shark itself.
An interesting fact about the shark’s tongue: unlike the human tongue, it consists not of muscles, but of two types of tissue: consisting of mucus and what is commonly called connective tissue.
The jaw of sharks is attached to the skull by the upper element of the hyoid arch. This type of attachment of the arch to the brain is called hyostyly.
Fins
A shark's fins allow it to quickly rise and fall to different layers of water. Most sharks have eight fins:
- a pair of pectoral fins;
- pair of ventral fins;
- two dorsal fins;
- anal fin;
- caudal fin.
The shark's pectoral fins are very rigid, due to which it has excellent maneuverability.
Representatives of the order Hexanchiformes have only one dorsal fin. The anal fin is absent in the orders Squaliformes, Squatiniformes and Pristiophoriformes.
Gill arches in a shark's jaw
Without gills, a shark cannot breathe. They are the main reason why oxygen gets inside the shark's lungs. The shark periodically draws water into its slightly open jaws. From here it goes to the gills, and oxygen begins to enter the shark’s lungs. That is why the shark’s jaw is always slightly open, so that if necessary, it can quickly enrich its body with oxygen. And the arrangement of the teeth in the jaw helps it do this as efficiently as possible.
The gills are connected to each other by the attachment of cartilaginous copulas. They are partially fused with each other. Why are gills arranged this way? There is a reason for this.
Before we find out, let’s add one more important fact. The gills of a shark have small processes that are thin and resemble stamens. They are placed so as to be at the same level with each other. For what?
Due to their location, the stamens in the shark's gills, which are attached through cartilage to the jaw, prevent large volumes of food from falling out through the gills. Because of this, the shark can hunt less and immediately digest more food than if some of it fell back into the water through the gills. Thus, we can conclude that gills not only help the shark breathe, but also help save the shark’s energy and time.
Shark gills in shark jaw
Internal organs
The shark's liver is large and accounts for 25% of the total body weight. It contains a large amount of fat and gives energy to the fish. This is a hydrostatic organ, it helps maintain buoyancy by containing a large amount of fat and thereby reducing body density.
The stomach is connected to the duodenum which ends in a spiral valve. The spiral valve increases the surface area through which nutrients from food are absorbed. It is connected to the rectum and anus.
Pancreas - transmits secretions through the vental lobe to the duodenum.
The structure of a shark's jaw - why is it unique?
A shark's main weapon is its teeth. Even a person who has never read about the structure of a shark’s jaw knows how sharp and dangerous they are. They are located in two rows. The number of teeth reaches ten thousand. And the record holder for the number of teeth is the whale shark. The total number of teeth is fifteen thousand.
Another amazing fact about shark teeth. Scientists have determined that they are scales of their own kind. But sharper and tougher. They include dentitis. However, the roots of shark teeth are very small. The second row of teeth plays the role of spare teeth. If the shark runs out of teeth on its first jaw, it will be able to use others from its second or third jaw.
How will a shark replace a lost tooth if the teeth are nearby and the rest of the teeth on the shark's jaw are still intact? This happens very quickly; the tooth located on the back jaw is automatically forced forward. Because of this, it does not have the same root as a human tooth. Thanks to this, the tooth can easily move and replace the lost one.
Sharks often replace their teeth, either as a preventative measure or due to diseases such as tooth decay. Predators such as tiger sharks replace teeth with entire jaws, and over the entire period of their existence replace tens of thousands of teeth with each other.
The jaw structure of sharks is identical. However, the shape of one shark's teeth is different from the shape of another shark's teeth. For example, a white shark's teeth are rectangular in shape, with smooth edges. To tear apart prey, a white shark only needs one row of sharp, jagged spaces on each tooth. But a more dangerous predator, the tiger shark, has two rows of notches on each tooth.
The record holder for length is the teeth found during excavations and reaching a length of 15 centimeters. They were found to be part of an extinct species of shark called megalodon.
The rate at which some shark teeth replace others depends not only on the circumstances, but also on the species of shark. For example, in representatives of the lemon shark species they change every seven days. And for a great white shark, it takes about 240 days for the teeth to naturally replace each other in the front jaw.
The shape of the teeth always has very sharp edges, with the help of which the shark easily tears apart what gets into its mouth. Due to the structure of its jaw, a shark can bite off and swallow large pieces of meat in a very short time. Although the speed of eating prey in horror films is indeed exaggerated, in nature the shark can also finish off its prey in a very short time.
The number of teeth may vary among sharks of the same species, but of different ages. As the number of years lived increases, the number of teeth also increases. Also, shark teeth often suffer from collisions with boards, paddles, surfboards and boats.
The shark's diet consists of large marine animals such as seals and fur seals. Their skin is very tough and sometimes you need to give up several of your teeth to bite through it. Sharks chose these animals as their prey precisely because their bodies contain large amounts of fat. And sharks need fat for large reserves of energy, which will give them the ability to move quickly, maintain the body temperature necessary for life and get their own food.
The shark's jaw is designed so that the shark can survive and feed itself
Thus, we can conclude that the structure of a shark’s jaw and the location of its teeth is formed due to many factors such as: prey, the need for fast movement, the need to obtain oxygen from the water and swim with its mouth slightly open, the presence of dental diseases and, most importantly, constant use teeth and the need to replace lost ones.
Read about cases of shark attacks on humans in the article:
- The most dangerous killer sharks for humans: top 10 list, description, photo
- Are there sharks in the Black Sea?
Muscles
A shark has two muscles:
- The red musculoskeletal muscle produces approximately 25-50% of a shark's strength and allows them to swim continuously. The red muscle fibers are concentrated in the shark's belly and are located near the spine, which strengthens its spine. Depends on temperature, at low temperatures it becomes useless.
- White musculoskeletal muscle - not so dependent on temperature. Important for tail movement, allows the shark to make fast and sudden movements.
We recommend reading: How much do sharks weigh and how long are they?
Dimensions
White sharks are not the largest of this type of predator. It is their dimensions that contribute to maneuverability during an attack and the ability to quickly grab the victim. The size of a white shark is 4-5 meters.
There were individuals that exceeded this figure, but these were isolated cases and were considered anomalous for this shark species.
Females are larger than males. The length of the white shark at birth reaches 1.3 m.
Concomitant pathologies
In humans, two types of teeth are generated - milk and permanent. There are 20 of the first ones, they appear in the second year of life, and by the age of 13-14 they all fall out. The latter begin to grow from the age of 6, and by the age of 3-14 they completely replace the “milk jugs”.
The change of bone elements is accompanied by resorption (absorption) of the roots of the “milk jugs” and their subsequent loss. Osteoclasts are directly involved in this - macrophage cells that destroy bone tissue. Resorption begins from the tips of the roots of the “milk jugs”, into which the crowns of the growing permanent units rest.
If the prolapse of the “milk jug” is delayed for any reason, the permanent element growing underneath it is forced to shift from its position and grow in the second row of the jaw arch, thus turning into a “shark”.
Supernumerary units are those that have grown beyond the required 32 units. The dimensions of a normal human jaw are designed to accommodate 32 units. Sometimes there are fewer of them, since not everyone grows third molars (“eights”). If there are more teeth than expected, they grow crowded or out of row.
Underdevelopment of the jaws also leads to a lack of space, only not for superfluous, but for “legitimate” complete elements. The development and proper growth of the jaws is influenced by many factors - the way the child is fed, breathing habits (nasal or oral), and some others.
In the presence of unfavorable conditions, the adequate formation of the jaws is disrupted, as a result of which they become narrowed and/or shortened with a cross, distal or mesial bite. On the reduced jaw there is not enough space for the entire set, so a second row appears - the shark one.
Causes of the anomaly
The eruption of elements in the second row of the jaw arch, and this is what characterizes the anomaly called “shark teeth,” most often occurs during the period of change in bite (6-12 years). In adults, this defect is also possible, but the defect is diagnosed much less frequently than in children.
Second line units have a negative impact on the oral cavity and some important functions. Chewing food worsens, diction is impaired, malocclusion develops, and facial aesthetics suffer.
There are three main reasons for the anomaly:
- Supernumerary elements.
- Underdevelopment of the jaws.
- Untimely (delayed) loss of milk jugs.
But these factors, in turn, are a consequence of other, more profound disturbances in biogenesis, which are completely unknown.
It is believed that the formation of anomalous phenomena occurs as a result of:
- hereditary burden;
- acute and chronic infectious diseases, especially those that interfere with normal nasal breathing;
- Sucking on a pacifier for too long;
- general unsatisfactory condition of the child’s body, reduced immunity;
- lack of nutrients and lack of solid food in the diet, which creates the necessary load on the jaw apparatus and stimulates the development of the jaws.
Causes of congenital absence of incisors and ways to eliminate the defect.
Read here about what problems can be solved using the Kois deprogrammer.
At this address https://zubovv.ru/ortodontiya/prikus/analizatora-hip-ploskosti.html we will talk about the purpose of the hip plane analyzer.
Lifespan
Ichthyologists from all over the world are trying to determine the exact period and life expectancy of the shark. She is about 70 years old. The vertebrae of the found specimens were examined. 4 sharks took part in the analysis and the following data was obtained, allowing us to find out how long sharks live: male - 73 years, female - 40.
There is no exact data on how many years sharks live, but it can be said that their average life cycle is 30-50 years.
Fangs of other predators
It's not just shark teeth that carry power. Here are more examples:
- Bear. This is the owner of the forest, a symbol of Russia. They used not only teeth, but even a whole paw. They used it to lock gates and barns. Breaking such a lock meant no luck in the hunt. The attacker was predicted to die from the paws of a bear. It is also protection from evil forces and slander. I took it with me during the day and put it under my head at night. This protected him from any misfortune. In folk medicine, bear teeth were used to treat toothache and back pain. Now it is an amulet for strength and invincibility, for protection from all kinds of misfortunes.
- Wolf. - a symbol of courage and self-confidence. With such a talisman, a person will go towards his goal, without turning back or stopping, without allowing even a shadow of doubt about his strength and luck. This is a symbol of freedom and independence, strength, dexterity. An indispensable amulet for those who risk their lives in the line of duty.
- . This beast symbolizes passion and sensuality. It is primarily used to enhance these properties. The owner of the amulet gains power over his mind and body. It will be useful for those who are prone to impulsive actions, who do not know how to use their capabilities and win the respect of others. In difficult situations, at turning points in life, the tiger's fang will point in the right direction.
- Crocodile. He is distinguished by strength, swiftness, fearlessness and ruthlessness. This predator symbolizes night and secrecy. The amulet is designed to endow the wearer with strength and endurance, fearlessness and composure.
Before purchasing an amulet, think carefully about whether such qualities are really needed. It may be better to use less aggressive items with magical meaning. For example, the teeth of a bear, wolf, tiger, and crocodile also have power. But the bear and the wolf are not so merciless, bloodthirsty and aggressive.
Nowadays on the Internet you can find any information or video in a minute, but before I learned all the interesting facts from educational programs on TV. I remember there was a channel where they told a lot of interesting things about the animal world for days on end. I really remember the creepy footage of 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’s fin was about to appear. Are sharks really as dangerous as we used to think?
Using the amulet
The talisman is especially recommended for use by indecisive and overly modest people. This will give determination and activity, which will help improve things professionally and in personal communications.
Businessmen are better off using white shark teeth to easily defend their opinions or tiger shark teeth to increase cunning. With this talisman, a person can easily come up with a trick to get out of a difficult situation. Feelings of powerlessness and fear will disappear. Shark teeth can also be used by students before important exams.
Pendants are often made from shark teeth. The easiest way to make it yourself is to wrap the upper part with a leather cord and wear it like that. More complex methods require the work of a jeweler. They insert the amulet into a gold or silver frame, which is complemented with patterns or protective signs that enhance the effect of the talisman.
Using a talisman as a pendant is not always appropriate. In this case, it is convenient to use a bag where the shark tooth amulet is placed. Can be made from several components:
- magnet;
- a piece ;
- dry angelica root;
- shark tooth
It is better to sew the bag from thick red fabric. The talisman will attract good luck in business. It is customary to carry it in the left pocket. To enhance the effect of the bag, experts advise placing a ball of white cat fur under the insole of your left shoe. If the talisman is made for a specific purpose, and not for abstract good luck, then a note with a wish is placed in the bag.
It is customary to make talismans on the waxing moon in complete solitude, banishing all extraneous thoughts from your head, focusing only on the goal.
If you move it over the wound, it will soon heal.
Such talismans should be handled with care. They are very sharp, so you should not wear them while sleeping or playing sports.
They are not supposed to be worn constantly, since the energy of the talisman is powerful and carries many negative traits that will spoil the owner’s character, making him aggressive, angry and merciless. People turn to the talisman for help only in moments of urgent need. Afterwards they thank you for your help, take it off and put it in a secluded place where no one will find it. This is a personal thing, so the touch of a stranger will spoil the powerful energy of the amulet and disrupt the connection with the owner.
Where does it live?
The habitat of man-eating sharks is huge. They are found both in coastal areas and further inland. Mostly sharks swim in surface waters, but some specimens could be found at a depth of more than 1 km. They prefer warm bodies of water; the optimal temperature for them is 12–24 °C. Desalinated and low-salt waters are not suitable for sharks.
Carcharodons are not found in the Black Sea
The main centers of concentration of predators include coastal zones in California, Australia, South Africa, and New Zealand. Sharks are also found:
- near the coasts of Argentina, the Republic of Cuba, the Bahamas, Brazil, and the east coast of the USA;
- in the east of the Atlantic Ocean (from South Africa to France);
- in the Indian Ocean (found near the Seychelles, in the Red Sea and the waters of the Republic of Mauritius);
- in the Pacific Ocean (along the west coast of America, from New Zealand to the Far Eastern territories).
Sharks can often be seen around archipelagos, shallows, and rocky headlands where pinnipeds live. Separate populations live in the Adriatic and Mediterranean seas. But their numbers in these reservoirs have decreased significantly in recent years, and they have practically disappeared.
