A goldfish is a kind of carp that is raised in aquariums. Their wild ancestors were slate gray; in captivity, they have been selectively bred for color, fin length, and body shape.
Contrary to popular belief, goldfish bowls are extremely unhealthful for goldfish. Instead, goldfish should have a well filtered tank with a minimum of 20 gallons for the first fish and 10 gallons for each additional fish.[1]