The presence of teeth, according to biologists dealing with evolution, one of the main reasons for the successful development of all vertebrates. Thanks to teeth-studded jaws living beings conquered the ancient sea and settled over time on the land. In fishes the teeth appeared, and generally the first animals, not immediately.
The edges of the jaw bones began to grow sharp rigid cones that allow a better grip on prey. Soon this advantage was crucial for survival, and gradually the oral instrument became larger and stronger. Eventually took tools for grinding, crushing, or grinding of food even.
Modern fish have a wide range of functions, which became possible with the help of teeth.
Many predatory fish, even after hundreds of millions of years, it is still possible to observe the original function of the teeth. For example, the jaw pike studded with hundreds of sharp needle as the cones. They have it firmly holds the prey until it is swallowed.
Fish with such teeth may, however, may eat only the food which is to be held not crushed through their throat.
Sharp teeth that allow you to split it into “portions”, fish our waters do not occur. Maybe fortunately. But sharp the teeth still created by nature. They are found, for example, many sharks, blue fish and piranhas. Nekotorykh is able to tear small pieces of meat from the bodies of large sea mammals such as seals and whales.
Brush and pharyngeal teeth
Widely held option teeth are the so-called “ishikawae”, or brushing, the teeth are perch, burbot and catfish. The plots are small and even a tiny hook-shaped needles forming a rough surface, which can firmly hold prey.
Fish with this shape of teeth adapted to hunt, sucking water from food through widely opened mouth. Big long teeth vacuuming up production impeded.
The unusual form of the pharyngeal teeth of cyprinid fishes. It is typical for each species and allows for clear determination of closely related fish. These teeth are used for grinding plants and crushing prey with hard shell, such as clams and crayfish.
Many predatory fish teeth include not only the jaw but the entire oral cavity. The teeth are on the plates of the sky, the Gill arches and the tongue.
The salmon is covered with the teeth of the sky, especially the so-called false bone, is a reliable method for determining species.
Making the teeth of fishes.
Fish tooth from korepodobnoj material of dentin is in the form of a cone, which is covered with an unusually hard layer of tooth enamel.
Tooth enamel consists of wear-resistant calcium phosphate (Apatite). It is preserved for millions of years in rocks, so from the long extinct ancient fish remains preserved, especially the teeth.
In fish, in contrast to people, there is a constant change of teeth.
Worn teeth fall out and are replaced by new. Such replacement occurs prior to end of life of the fish.
Jaws studded with teeth of various ages and it is the kind that always provides the function of biting. Predatory fish do not have teeth, would have difficulties with the retention of production and are unable to continue their family line, as would have perished from hunger.
Thus, the evolution of any fish contributes to her teeth changed. Popular opinion that pike in the summer refreshes the teeth and therefore cannot eat, is a fairy tale.