eel going downstream to spawn
Refers specifically to eels migrating downstream for spawning, a seasonal phenomenon.
In autumn, eels going downstream to spawn can be seen in the river.
Standard kanji spelling for this term.
Variant spelling without the okurigana ち.
Compound of 落ち (ochi, 'falling' or 'descending') and 鰻 (unagi, 'eel'), describing eels that descend rivers to spawn.