Goldfish Information & Care

The goldfish (Carassius auratus auratus) is one of the earliest fish to be domesticated and is still one of the most commonly-kept aquarium fish. A smallish member of the carp family (like the koi), the goldfish is a domisticated version of a dark-gray carp native to East Asia, first domesticated in China was introduced to Europe in the late 17th century. It will grow to a maximum length of 23 inches (59.0 centimeters) and a maximum weight of 6.6 lbs (3.0 kg).

Goldfish natively live in rivers, lakes, and other slow or still moving bodies of water in depths up to 65.6 ft (20 m). They natively live in a subtropical climate and prefer freshwater with a 6.0 - 8.0 pH, a water hardness of 5.0 - 19.0 dGH, and a temperature range of 32 - 106 °F (0 - 41 °C). Their diet consists of crustaceans, insects, and plant matter. They lay their eggs on aquatic vegetation.

Part of its popularity is due to the goldfish's hardiness. It is a cold-water fish, and can live in an unheated aquarium or in an outdoor fishpond. In a pond, it will even survive brief periods of ice forming on the surface, so long as there is enough oxygen remaining in the water. Although edible, the fish are rarely eaten.

Selective breeding has produced several colour variations, some of them far removed from the "golden" colour of the original. There are also different body shapes, fin and eye configurations. Such extreme versions of the goldfish do need to be kept in an aquarium — they are much less hardy than varieties closer to the "wild" original.

Goldfish and other carp fishes are frequently added to stagnant ponds in order to reduce the mosquito populations. Their introduction often has unfortunate consequences for local ecosystems, however.

From wikipedia.org