Common Goldfish
The common goldfish is a breed of goldfish that is simply the direct descendant of its ancestral genetic goldfish. The only genetic modification that has been made to the common goldfish is its color patterns and variation. All of the goldfish that are referred to as “fancy” can trace their genetics back to the common goldfish. Common goldfish are very hardy, which is one of the reasons why they are currently extremely popular among fish owners all over the world. They can live both indoors and outdoors, and are also very easy to breed. In general, the common goldfish is able to accept greater variations in temperature and water quality than fancy goldfish. If kept in optimum conditions, the common goldfish is able to live more than 10 years in aquarium conditions.
Though it is possible to keep common goldfish alone, they prefer to be kept in groups. They are very social, and will usually interact well with most other types of fish with similar temperaments. If subjected to proper care, it is possible for a common goldfish to become relatively tame. They can be trained to approach the edge of the tank at mealtimes, and may even rise up to the top of the tank to “greet” their owners. Over time, they may come to directly take food from the hand of their owner. They socialize with other fish by rubbing their body up against the fish, and may display this behavior when attempting to socialize with humans as well.