Oncorhynchus masou macrostomus

The amago or the red-spotted masu salmon (Oncorhynchus masou macrostomus) is a salmonid fish endemic to western Japan, and a subspecies of the more widespread Northwest Pacific masu salmon or cherry salmon (Oncorhynchus masou). It is distinguished by the presence of red or vermilion spots on the body along with black ones, while the nominate form O. masou masou, known as the yamame, only has black ones. The amago is distributed in western Japan, on the Pacific side of the Honshu and Shikoku islands, and on the Inland Sea of Japan side of Kyushu. The subspecies is a subject of aquaculture. It can grow up to 50 cm (20 in) length.

There are both anadromous (sea-run) and persistently stream-dwelling populations of the amago. Previously it was considered a subspecies of Oncorhynchus rhodurus, a name that currently only refers to the Biwa trout, which has a restricted distribution within the range of the amago.