Sole blending in with the sandy surface

Flatfishes have both eyes on the same side of the head. The body is disk-shaped or oval. These fishes are 1 in (2.5 cm) to 6.5 ft (2 m) long and weigh as much as 661 lbs (300 kg), but most are about 12 in (30 cm) long. The eye side of most flatfishes is dark brown or black, sometimes with spots, bands, or wavy stripes. The other side is usually white or pale yellow. Flounder, halibut and sole are some of the well-known species and they are a big human food source.

Except for halibuts, which chase other animals for food, flatfishes lie on the bottom and wait around to ambush their prey. When flatfishes swim, they glide with wavy movements. Most flatfishes are active during the day, some around sunrise and sunset, and others at night. Flatfishes do not form schools.

All flatfishes begin life with one eye on each side of the head. During the change from larvae to adults, one eye moves from one side of the head to the other, so that both eyes end up on the same side. Depending on the species, either the right or the left eye migrates. The eyes may be close together or far apart when the eye travel is completed. After their eyes move to one side of their head, flatfishes stay living on the sea floor. Many of the species have excellent camouflage that allows them hide in plain site, resting on the sea floor.