What does a flounder look like:

The flounder, also known as the plaice, is the generic name for fish in the order Plaice, a group of bony fishes. The body is laterally compressed, long oval, ovoid or long tongue-shaped, the maximum body length of up to 5 M. The adult body is not symmetrical.

Both eyes are located on the left or right side of the head. The mouth is slightly protruding. The fins are generally without spines. The dorsal and anal fins are basally long and may or may not be attached to the caudal fin. Widely distributed in warm and hot seas of all oceans.

The flounder is a collective name for the flounders. It has no swim bladder and feeds on worms, crustaceans and other animals. In biological taxonomy it belongs to the class of Spoke-finned fishes, the order Platyhelminthes? .

The flounder has a flattened body, with eyes growing on only one side of the body, and has an asymmetrical structure unique among fish?

The flounder has a flat body with eyes that grow on only one side of the body, a unique asymmetrical structure among fish?

The flounder is thought to have evolved from a basically symmetrical sea bass (sea bass) that was used to resting on one side. There are about 570 species of flounder in the world, which can be divided into 11 families.

The most primitive family of flounder is the Flounderidae, with pectoral and anal fins very similar to those of the sea bass, and only the eyes and long dorsal fins differ from those of the sea bass, suggesting that the flounder evolved from an ancestor of the perch-shaped fish? .

All adult flounder are bottom feeders, but their eggs contain oil droplets that float near the surface. The eggs hatch after a few days, and the hatchlings are symmetrical, with two eyes on each side of the head and a mouth on the ventral midline, which further suggests that they evolved from sea bass.

When the larvae grew to about 1 centimeter in length, a deformation change occurred that dramatically affected the symmetrical cranium, ultimately creating the asymmetrical flounder we see.

The whole change starts with one eye moving to the other side of the fish's head, which is done by resorption of strips of cartilage on the skull. Similarly the nostrils move to the side with 2 eyes or to the side with color.

The mouths of other families of flounder, besides the flatfish, move to the same plane as the eyes. The form in which the eyes move is also typical of some particular families. For example, fish in the families Turbotidae and Flounders are called "left-eyed flounders" because their right eye usually moves so that the colored side of the body ends up facing upwards on the left side.

Fish in the plaice family are "right-eyed flounders" because their left eye usually moves and they end up with their right side facing up. In the thick family, there are an equal number of right-eyed and left-eyed flounders.