landlocked variety (of fish)
Technical term in biology/ecology for a fish population that is confined to freshwater and does not migrate to the sea, often contrasted with anadromous or sea-run forms.
A landlocked variety of cherry salmon inhabits this lake.
Compound of 陸 (land), 封 (seal, confine), and 型 (type, form). The term is a modern scientific coinage describing fish that are 'land-sealed' or confined to freshwater.