Difference Between Goldfish and Koi

Goldfish vs Koi

Both goldfish and koi are popular ornamental fishes in the Family: Cyprinidae. These beautiful and attractive creatures moving through the water column of your fish tank could make your heart perform without problems according to the cardiologists. However, their beauty cannot beat each other, but the differences between them are important to notice.

Gold Fish

Goldfish, Carassius auratus, is a domesticated ornamental freshwater fish species. There are different breeds of goldfish, developed by selective breeding by human. They vastly vary in colour, body and fin shape, and body size. Black moor, Celestial eye, Comet, Fantail, Pearl scale, Butterfly tail, Panda moor, and Lion head are some of the popular breeds of goldfish with varying features. The common goldfish is shiny orange in colour and a small-bodied fish, but it could grow large in muddy tanks. Goldfish are very popular because of the small size, affordable or inexpensive, colourful, and hardy. In temperate climates, they are very active except during winter. However, goldfish produces a large amount of waste from their faeces and through the gills. Therefore, frequent cleaning of the tank is a requirement before it gets toxic for the fish. In wild, they consume crustaceans, insects, and various plants. In contrast to many fish species, goldfish are intelligent and they easily respond to external signals. They are gregarious fish and love to be social. People in China have started to breed goldfish in captivity before a thousand years from a Prussian carp.


Koi is an ornamental variety of common carp, Cyprinus carpio. They have stout and elongated bodies, and their fins are short but full of colours. They have distinctive and colourful body patches those make koi fish attractive. Usually, koi fish prefer outdoor ponds or water gardens. They have a range of colours including white, black, red, yellow, blue, and cream. The special feature about koi fish is that they do not have varying body shapes across their breeds, but coloration and scalation could vary. Koi fish has two small whisker-like sensory organs hanging in their mouth known as barbels. Japanese started to breed koi as an ornamental fish in the early 19th century from a common carp.

What is the difference between Gold fish and Koi?

• They both belong to one Family but two genera in the taxonomy.

• Koi is a developed form of the common carp, whereas goldfish is a selectively bred form of Prussian carp.

• Japanese bred the koi as an ornamental fish before 200 years, but Chinese bred the goldfish before 1,000 years.

• Koi breeds vary only in their colour patterns, while goldfish breeds vary in colours and shapes of their bodies and fins.

• Koi is usually larger than goldfish.

• A koi has a longer lifespan than a gold fish.

• Koi has barbels around the mouth but goldfish does not.