Why flatfish is flat: a scientific explanation

Flounder is a fish that has a flat body, families Kambalov, subfamilies Kambalopodobnye.

Why flat flounder

All members of this family have a flattened asymmetrical shape, resembling a pancake, which either lies on the bottom of the sea, or floats, but only on one side, and the eyes of the fish are located side by side.

Previously, they did not have this feature, moved in a standard way and had a normal form. So why flatfish? Because so it became easy prey for enemies, and it was necessary to evolve, after which these fish began to swim and lie only on one side. And after thousands of years, they all took on a flat form. This meant that one eye would remain located to the ground, and the mouth was in an uncomfortable position for eating. In this connection, in the course of a long evolution, the lower eye gradually moved upward, for convenience. Thus, both visual organs were on an asymmetrical head, on the one hand, on which fins also are located.

Although the river fry at birth, the eyes are located as standard, on both sides of the head. As they grow, they shift to one side, most often to the right. The upper part has a color, the reverse always remains white. River species grow to fifty centimeters, weighing up to three kilograms. Marine species can reach much larger sizes. They have an unequal color, a straight tail, and a mouth that is perpendicular to the bottom.

Features of flounder

It is able to change the color for masking purposes. But this feature is characteristic only for sighted species. For greater secrecy he sprinkles himself with sand and merges with the bottom, quietly waiting for the prey. So they almost completely hide under the ground, leaving the upper part of the head with the eyes outside.

This happens very cleverly, in the course of wavy movements: the ground rises, and the fish continues to burrow into the formed depression. The underside is rough, resembling sandpaper, it helps it to move freely on sharp stones and pebbles.

These fish move very little. They swim at the expense of the dorsal and anal fins. They basically move in their usual state, but in case of danger they can turn over to the edge and continue to move in this position until they fall to the bottom to dig into the ground.

They feed on crustaceans, mussels and fry, worms and small bottom fish, grabbing it with a throw when it comes close. They have developed strong teeth. Spawning, depending on the habitat, from January to May. The female swallows up to two million eggs.

As the structure of the fish explains physics

Why flatfish? Physics treats this as follows. This fish lives at great depths where the pressure is very high. And in order not to experience overloads, it has this form. The body from above is subject to the minimum pressure.

Why flatfish? This is also due to the bottom life, which contributes to the redistribution of the pressure load.

Most of the representatives of the family live in coastal waters, at a moderate depth, and only a few overcome the distance of more than 1 thousand meters to search for food. Certain species live in salt water. They can climb up the river.

Evolution of their development

Why flatfish? The scientific explanation is as follows. Based on the fossils found, scientists have built a chain of evolutionary development of this family.

Flounder is a relative of the trout and herring, and its body was originally oriented in a vertical plane. Consequently, the ancestors fell to the bottom sideways, not belly. And at first the fish had to rise on the fin to see better, then this need disappeared, but the reception was preserved.

Now it is clear why the flounder is flat.