Oncorhynchus mykiss (Walbaum, 1792)

– Rainbow trout; Truta-arco-íris ①②③

O. mykiss is an alien and invasive species introduced in Portugal. This species is primarily a freshwater fish, although sea-run populations, often known as steelhead, exist in some areas. However, populations of O. mykiss are capable of migrating to and surviving in the sea (Jonsson 2011).