Carassius is a genus in the ray-finned fish family Cyprinidae. Most species in this genus are commonly known as crucian carps, though that term often refers specifically to C. carassius. The most well known species is the goldfish (C. auratus). They have a Eurasian distribution, apparently originating further to the west than the typical carps (Cyprinus genus, which includes the common carp).
Species of Carassius genus are not closely related of the typical carps of Cyprinus genus, but rather form a more basal lineage of the subfamily Cyprininae.[1]