noun
catadromous fish
Technical term in biology for fish that migrate from freshwater to the sea to spawn, such as eels. Contrasts with 遡河魚 (anadromous fish).
See also: 遡河魚
ウナギは降河魚の代表例である。
The eel is a typical example of a catadromous fish.
降河魚は産卵のために川から海へ下る。
Catadromous fish migrate downstream from rivers to the sea to spawn.