Pseudopleuronectes obscurus, or dark flounder[1] is a flatfish of the family Pleuronectidae. It is a demersal fish that lives on salt bottoms in the temperate waters of the northwestern Pacific, from Hokkaido to the Kuril Islands, the Sea of Okhotsk, Sakhalin and the Tatar Strait to the northeastern coast of Korea and the Yellow Sea. It can grow up to 56cm (22inches) in length, though it more commonly reaches around 35cm (14inches), and its maximum recorded weight is 2.6kg (05.7lb).[2]