The goldfish (Carassius auratus) is a freshwater fish belonging to the family of carps. It is closely related to the common carp and the Koi. It was one of the earliest fish to be domesticated, and is one of the most commonly kept aquarium and pond fish. It is best kept in larger groups. As the carps, also goldfish are omnivorous.

The goldfish is said to be a colourful version of the drab brownish crucian carp. It was first domesticated in China more than a thousand years ago, where red forms of the fish have been selected and further bred, e.g. at the palace of the emperor of China. Since then, various forms have been bred which show different colours and patterns, fin forms and body shapes. Popular variants are the Comet Tail, Buffalo Head (Ranchu) or Lions Head (Oranda). Some variants with extreme deformed bodys, long fins or bubble eyes are considered torture breeding. Depending on the type of breed, goldfish can grow up to 25cm and live up to 30 years old.

The fish scale consist of a bony part and collagen fibers. The scales grow differently depending on the time of year, this leads to structures that look like annual rings from a tree.

Some information in this copy may have been obtained from the online resource: Wikipedia: The Free Encyclopedia.

Learn more: http://en.wikipedia.org/wiki/Goldfish