Oncorhynchus masou, known as the masu salmon or the cherry salmon, is a species of salmon found in the Western Pacific Ocean along East Asia, ranging from Kamchatka, Kuril Islands, Sakhalin, Primorsky Krai south through Korea, Taiwan and Japan. There are a number of subspecies, including Oncorhynchus masou masou (e.g. in Korea), the critically endangered, landlocked Taiwanese or Formosan salmon Oncorhynchus masou formosanus found in certain freshwater systems of Taiwan, and the masu salmon Oncorhynchus masou macrostomus in Japan. All three subspecies are sometimes collectively referred to as the masu salmon.