What's a goldfish?

Goldfish: Carassius auratus auratus

The goldfish is classified as a variety of the species Carrasius auratus and belongs to the family Cyprinidae, a family that includes carp. The details of this species are still murky and questions remain about just who belongs to this species [1].

Goldfish look like carp, but they don't have barbels, the structures that look like whiskers under the corners of the mouth.

They were the first fish to be domesticated more than a thousand years ago in China, during the Sung Dynasty [2]. Today goldfish are kept as pets and as a source of food for other pets. Unlike carp, people don't eat many goldfish. Goldfish fanciers around the world breed fish into many forms that highlight bright colors and fancy shapes and share their enthusiasm with other fanciers at conventions and events run by local clubs.

In the wild, goldfish live in groups in quiet streams and ponds. The wild species are much duller in shades of grayish-green and brown. Their omnivorous habits and abilities to tolerate large fluctuations in temperature, turbidity and oxygenation make them convenient pets from the human perspective. They can live for a short while in a poorly-suited environment such as a glass bowl better than other fish. By matching their true environmental preferences though, they can live for 20 years or more.

Fancy goldfish have been produced in a dazzling array of colors that include white, black, gold, orange, red and mixed colors. They also come in many fancy forms, some with fancy frilly tails and popped-out eyes. They are charming because of their ability to connect with their owners. Scientists are just beginning to learn more about how goldfish think. Some have been trained to do things such as pushing a lever at a certain time of day for food [x], recall for three months [x], and even swim in formation [x].

Although their adaptations make goldfish relatively hardy pets that can survive for a short time in a dirty goldfish bowl, under circumstance they can live for x years in captivity. In it is illegal to In some places, you may be able to spot feral goldfish, ones that used to be pets that have been released into the wild. Like all feral animals, they can sometimes compete and wipe out native species, so they should not be released.

Goldfish biology
http://fisc.er.usgs.gov/Carp_ID/html/carassius_auratus.html http://www2.dpi.qld.gov.au/fishweb/2402.html How to care for a goldfish Goldfish stories
Looking for a good fancy goldfish site with photos http://www.goldfishsociety.org/links.html

To learn more about the life cycle of salmon:
University of Washington Research & Teaching Hatchery