Paralichthyidae in the context of "Game fish"

Flatfish are a group of ray-finned fish belonging to the suborder Pleuronectoidei and historically the order Pleuronectiformes (though this is now disputed). Their collective common name is due to their habit of lying on one side of their laterally-compressed body (flattened side-to-side) upon the seafloor; in this position, both eyes lie on the side of the head facing upwards, while the other side of the head and body (the "blind side") lies on the substrate. This loss of symmetry, a unique adaptation in vertebrates, stems from one eye "migrating" towards the other during the juvenile's metamorphosis; due to variation, some species tend to face their left side upward, some their right side, and others face either side upward. Pleuronectidae lie on their left side, with eyes on the right. Paralichthyidae lie on their right side, with eyes on the left.

They are one of the most speciose groups of demersal fish. Their cryptic coloration and habits, a form of camouflage, conceals them from potential predators.

Pleuronectidae, also known as righteye flounders, are a family of flounders. They are called "righteye flounders" because most species lie on the sea bottom on their left sides, with both eyes on their right sides. The Paralichthyidae are the opposite, with their eyes on the left side. A small number of species in Pleuronectidae can also have their eyes on the left side, notably the members of the genus Platichthys.

Their dorsal and anal fins are long and continuous, with the dorsal fin extending forward onto the head. Females lay eggs that float in mid-water until the larvae develop, and they sink to the bottom.