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.[1] 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.[2][3]
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.[4]
They are found on the bottoms of oceans around the world, with some species, such as the Atlantic halibut, Hippoglossus hippoglossus, being found down to 2,000 m (6,600 ft). The smaller species eat sea-floor invertebrates such as polychaetes and crustaceans, but the larger righteye flounders, such as H. hippoglossus, which grows up to 4.7 m (15 ft) in length,[5] feed on other fishes and cephalopods, as well.