Flatfishes: Pleuronectiformes

Flatfishes have both eyes on the same side of the head. The body is disk-shaped or oval. These fishes are 1 inch (2.5 centimeters) to 6 feet, 6 inches (2 meters) long and weigh as much as 661 pounds (300 kilograms), but most are about 12 inches (30 centimeters) 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. The dorsal (DOOR-suhl) fin, the one along the center of the back, extends from just above the eyes to the tail. The anal fin, the one along the midline of the belly, also is quite long. Adult flatfishes do not have a swim bladder, an internal sac that fishes use to control their position in the water.