The Common Goldfish is perhaps the most commonly kept aquarium fish in the world.

Common Goldfish are often kept by children in Goldfish bowls as a first fish. They non-aggressive and very hardy making them an excellent first fish. With the proper care this fish can live an amazingly long time. It has been reported that some individuals may reach as old as 45 years. Although the Goldfish has been kept in a bowl for many years, this fish actually does significantly better in aquariums with filtration. The problem with goldfish bowls is not limited to one thing. Some of the issues associated with goldfish bowls are as follows. In the small bowl there is often not enough surface area of the water to allow enough oxygen to pass into the water. Additionally there is usually no water filtration at all. Goldfish are messy fish and the water quality will drop quickly. Most Goldfish bowls lack proper lighting. Full spectrum light is important for all fish. Lastly Goldfish can grow quite large and the typical goldfish bowl is not going to be large enough. Ideally Goldfish do best in at least a 10-gallon aquarium. The average lifespan of a goldfish that is kept in a proper aquarium is 5 to 7 years. Overfeeding, and underfeeding are two of the most common mistakes beginners make with the Common Goldfish. A good rule of thumb is to put in only as much food as they can eat in two minutes. Do this twice a day.

The Common Goldfish is orange, though there are several different color variants that may include black spots or orange spots. Also many other varieties of Fancy Goldfish have been developed from the humble Common Goldfish. Though many people may not realize it, the Common Goldfish can grow quite large in the right conditions. Some individuals have been reported as long as 40 inches.

The Common Goldfish (Carassius auratus) is a close relaive to the Crucian Carp (Carassius carassius). The are native to Asia. They have been bred in China since at least 1000 AD. Today they are popular aquarium pets and are also used as feeder fish for other fish and reptiles.

The Common Goldfish is omnivorous and does quite well on a diet of formulate goldfish food. The Common Goldfish does well in temperatures that range from 60 degrees to 75 degrees Fahrenheit. The seem to tolerate a wide range in pH from 6.0 to 9.0.

The Common Goldfish is regularly bred in captivity.