Speaking of sharks, I think everyone will not be unfamiliar, we have learned the hegemony of this ocean in the language textbook since we were young, but how can sharks dominate in the vast ocean? Today's article will explain the secret weapon of sharks.
Sharks have evolved from 350 million years ago to the present in order to fight for food and space, and naturally have their advantages over other fish species. For example: large body size, few natural enemies in adulthood, special breeding methods, rapid hatching and growth, sensitive sense of smell... Sharks' reincarnated teeth are one of the tools that make sharks the hegemons of the sea.
Once the shark's outer teeth are worn, the inner teeth will be replenished sequentially, so that its predatory tools are always kept up to date. Such a mechanism that constantly renews its teeth allows sharks to be ready to hunt food and enjoy the delicacies at any time.
Sharks have a row of new teeth that tend to be larger than old ones, and the reason for this is to match the shark's growth. Shark teeth are jagged, so that sharks can not only bite the prey tightly, but also effectively tear the prey apart when facing large prey.
Many large sharks will first circle 2.4 to 3 meters away from their prey before attacking, and then slowly shrink the circle of rotation, and when the time is ripe, they will rush forward and bite the prey with their mouths. If faced with large prey, sharks also have their own unique methods, after a few large bites, they will continue to bite along the body of the prey, just like people nibble on corn.
In fact, shark teeth have many forms and sizes, and these teeth have made a great contribution to the supremacy of sharks. There are three main types of taxonomy, the thinner and sharper spear-like or tooth-like teeth are used to catch slippery fish or squid, the very large flat teeth are used to crush shellfish or other hard prey, and the sawtooth is used to bite large prey.
In addition, sharks have many very small teeth that need to be observed through a microscope, not to mention that these teeth are small and can exert great power in the face of food that is difficult to decompose. The tiny but sharp scales that cover the shark's body also extend into the shark's jaw, where they are used as teeth.
Most of the vertebrate teeth grow on the jawbone, but the shark's teeth grow on the skin, and as the shark grows, the teeth move forward, and finally the root of the tooth is exposed, and the tooth is almost out of service. Sharks without teeth are like warriors without weapons, and finally disappear into the depths of the sea.
Although shark teeth can be constantly renewed, sharks do not squander the sharp weapons in their mouths without knowing how to protect. In the case of the mackerel, for example, many people still believe that the mackerel will only hunt fish and some squid, on the grounds that they do not have flat teeth or mortar plates like sharks that use crabs or shellfish as their staple food, so according to common sense, the mackerel will not prey on these foods with hard shells.
But when a scientist threw crabs into a shark pond by chance and discovered that the dog fish was greedily eating the crab, he immediately asked: How do the dog fish use sharp but slender fangs like nails to bite the crab? Wouldn't it hurt your teeth?
He then immediately went to check the report on the contents of the dog's stomach and found that shellfish accounted for more than 40% of the dog's diet. He was intrigued by the discovery, so he took the teeth of the fresh dead sample and squeezed it with the glass. He observed that there was a wide ligament that would pull the tooth, causing it to be buried and look as if it were bent.
Subsequently, as he exerted more force, he observed all the teeth bending backwards, with one row of teeth partially overlapping behind another row. These folded teeth provide a flatter but powerful surface for the mackerel to safely crush crabs or shellfish.
Scientists have built a biophysical model to explain why dog fish chew crabs with relish. They concluded that when the teeth are bent, the force of the bite comes mainly from the flat front surface of all the teeth, and uses this to contact the prey, through such a mechanism, it can protect any tooth from damage.
The jaw performs this bite action much like the herbivores' jaws chewing on grass. But unlike herbivores, when a dog bites a hard meal, all its teeth immediately stand up to its original sharp shape, ready to continue preying on other fish.
In addition to the dog mackerel, other sharks without flat teeth or mortar plates can also apply this model. All living things in nature today, in order to survive in nature, will develop some modes of adaptation to the environment, and the teeth of the dog fish prove this statement! In addition to teeth, I think there are many wonderful properties in the biological world waiting to be discovered.
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