Goldfish

thumb|Feral goldfish found in Essex County, Ontario. thumb|Carassius auratus by Alexander Francis Lydon. The goldfish (Carassius auratus) is a freshwater fish in the family Cyprinidae of the order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the wild have become an invasive pest in parts of North America and Australia.

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thumb|A nigorobuna of Lake Biwa