anadromous fish
Technical term for fish that migrate from the sea up rivers to spawn, such as salmon. The reading さっかぎょ is also listed but is less common.
See also: 降河魚
Salmon is a typical anadromous fish.
遡河魚は産卵のために川を遡ります。
Anadromous fish go up rivers to spawn.
Catadromous fish that migrate downstream to the sea to spawn, e.g. eels. Opposite migration pattern.
Standard kanji spelling using 遡 (go upstream).
Variant spelling using 溯, which also means go upstream. Less common than 遡河魚.
From 遡河 (soka, 'going upstream') + 魚 (gyo, 'fish'). The kanji 遡 means 'go upstream'.