【Reading】ます

【English Name】Trout

Among the fish belonging to the family Salmonidae in the order Salmoniformes, masu (trout) is the collective term for species excluding the so-called salmon group such as shirozake (chum salmon) and benizake (sockeye salmon). Representative examples include nijimasu (rainbow trout), sakuramasu (the sea-run form of yamame / cherry salmon), iwana (char), and amago.

Although it corresponds to the English "trout," the criteria separating salmon and trout are academically ambiguous as well, and the way of dividing them varies by country. As one example, king salmon, classified as salmon in English-speaking regions, corresponds to masunosuke by Japanese name. Worldwide, 11 genera and roughly 66 species have been confirmed, and debate over classification continues even now.

The center of natural distribution is the high-latitude regions of the Northern Hemisphere, where they seek spawning grounds in cool rivers and lakes whose water temperatures do not exceed 20°C. Among the fry born, some descend to the sea and grow through a migratory life. In the Southern Hemisphere, their range expanded through stocking in Australia and Chile.

As sushi toppings, sakuramasu and trout salmon (rainbow trout) are especially favored. The flesh, endowed with rich umami, is used not only for nigiri and sashimi but also in a wide range of dishes such as salt-grilling and meuniere. The naming of salmon and trout species in Japan is historically tangled, with a background in which separate Japanese names were given to the sea-run form and the land-locked form.