The Ridged-eye flounder, Pleuronichthys cornutus, is a flatfish of the family Pleuronectidae. It is a demersal fish that lives on sand and mud coastal bottoms at depths of between 2 and 170 metres (6.6 and 557.7 ft). Its native habitat is the temperate waters of the northwestern Pacific, from southern Hokkaido to the Korean peninsula, the Bohai Sea, the Yellow Sea and the South China Sea. It can grow up to 30 centimetres (12 in) in length, and can weigh up to 1 kilogram (2.2 lb).