Round crucian carp

Nigoro-buna, sometimes called round crucian carp, is a type of wild goldfish or related cyprinid endemic to Japan. Its habitat is limited to Lake Biwa, its tributaries and distributaries, and irrigation canals, in the Shiga Prefecture, northeast of Kyoto.

The fish is of culinary importance locally in Shiga Prefecture, where it is used as an ingredient for funazushi, a type of narezushi. The fermented fish is closely packed with rice and salt in tubs.