Gold Fish

The goldfish is a freshwater fish in the family Cyprinidae of order Cypriniformes. It was one of the earliest fish to be domesticated, and is one of the most commonly kept aquarium fish.
Goldfish were bred from Prussian carp in China, and they remain the closest wild relative of the goldfish. Previously, some sources claimed the Crucian carp (Carassius carassius) as the wild version of the goldfish. However, they are differentiated by several characteristics. C. auratus have a more pointed snout while the snout of a C. carassius is well rounded. C. gibelio often has a grey/greenish color, while crucian carps are always golden bronze. Juvenile crucian carp have a black spot on the base of the tail which disappears with age. In C. auratus this tail spot is never present. C. auratus have fewer than 31 scales along the lateral line while crucian carp have 33 scales or more.