China and Japan, and the ranchu breed was derived from them. A dorsal fin is found on all normal fish. This fin keeps the fish stable in the water and keeps them from rolling. Swimming speed, acceleration, and efficiency are all slower in goldfish missing dorsal fins than in normal goldfish. They must also deal with a tendency to roll to the side while moving or at rest, as well as a lack of directional stability. See also Goldfish Lionhead Lionchu Oranda References