Flounder is a flat-bodied fish, families of Flounder, subfamilies Flounder-like.
Why is flat flounder
All representatives of this family have a flattened asymmetric 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 nearby.
Previously, they did not have this feature, moved standardly and had a normal shape. So why is flounder flat? Because this way it became easy prey for enemies, and had to evolve, after which these fish began to swim and lie only on one side. And after thousands of years they nevertheless gained a flat shape. This implied that one eye would remain located toward the ground, and the mouth was in an awkward position for eating. In this regard, in the process of long evolution, the lower eye gradually moved upward, for convenience. Thus, both visual organs appeared on an asymmetrical head, on the one hand, on which fins are also located.
Although in river fry, at birth, the eyes are located standardly, on both sides of the head. As they grow, they shift to one side, most often to the right. The upper part is colored, the reverse always remains white. River species grow up to fifty centimeters, weighing up to three kilograms. Sea species can reach much larger sizes. They have uneven coloring, a straight tail, and a mouth perpendicular to the bottom.
Flounder Features
Able to change color for camouflage purposes. But this feature is characteristic only for sighted species. For greater conspiracy, showers itself with sand and merges with the bottom, quietly waiting for prey. So they almost completely hide under the ground, leaving the upper part of the head with eyes outside.
This happens very adroitly, when making wave-like movements: the soil rises, and the fish continues to dig into the formed recess. The underside is rough, resembling sandpaper, this helps it to move freely on sharp stones and pebbles.
These fish move quite a bit. Swim due to dorsal and anal fins. Basically they move in their usual state, but in case of danger they can roll over to the rib and in this position continue to move until they sink to the bottom to dig into the ground.
They feed on crustaceans, mussels and fry, worms and small bottom fish, catching it with a throw when it swims close. They have developed strong teeth. Spawning, depending on the habitat, from January to May. The female tosses up to two million eggs.
How physics explains the structure of fish
Why is flounder flat? Physics interprets 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 above is subject to minimal pressure.
Why is flounder flat? This is also explained by the near-bottom lifestyle, which contributes to the redistribution of pressure load.
Most members 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 is flounder flat? 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 trout and herring, and her body was originally oriented in a vertical plane. Consequently, the ancestors lay on the bottom sideways, not the stomach. And at first the fish had to climb on the fin to see better, then this need disappeared, but the reception was preserved.
Now it’s clear why the flounder is flat.