noun
young sweetfish; young ayu
Refers specifically to juvenile sweetfish (Plecoglossus altivelis), often in the context of fishing, aquaculture, or seasonal cuisine.
春になると川で稚鮎が泳ぎ始める。
In spring, young sweetfish start swimming in the river.
この地域では稚鮎の放流が盛んだ。
Releasing young ayu is popular in this region.
鮎 is the general term for sweetfish (ayu), while 稚鮎 specifically means young or juvenile sweetfish.
Compound of 稚 (chi, 'young') and 鮎 (ayu, 'sweetfish'). The reading ちあゆ follows standard on-kun combination.