Carassius is a genus in the ray-finned fish family Cyprinidae. Many species in this genus are commonly known as crucian carps, though this term often specifically refers to C. carassius. The most well known is the goldfish (C. auratus), which was bred from the Prussian carp (C. gibelio). They have a Eurasian distribution, apparently originating further to the west than the typical carps (Cyprinus), which include the common carp (C. carpio).