Carassius cuvieri, the Japanese crucian carp or white crucian carp, is a species in the genus Carassius. It is found in Japan and, as an introduced species, in Taiwan. This fish is closely related to the commonly known goldfish. The gengorō-buna is being used as a substitute for the depleted stock of nigoro-buna (Carassius auratus grandoculis) in the preparation of the intense-smelling fermented local dish (funazushi) due to the nigoro-buna's falling numbers.