The Goldfish is probably the most popular, and, unfortunately, the most mistreated aquarium fish around. What is often not recognized is that Goldfish are a coldwater species and thus require different care than a tropical species. They do best in water at lower temperatures, surviving in conditions that a neon tetra, for example, could not. They can be found everywhere from backyard ponds to tiny (and cruel) two gallon "Goldfish bowls."

Tank Setup

A two-inch Goldfish requires, at the very least, five gallons of water. When provided with less space its growth will be stunted and its life span shortened. In a favorable environment, however, a Goldfish will live for as long as 15 years.

If there are too many Goldfish in an aquarium, they will be seen gasping at the surface for air. If the fish must be kept in a non-aerated container, select the one that has the largest surface area. More oxygen will be absorbed through this greater area. A bowl with no aeration must be cleaned at least once a week. Even in well-cleaned tanks, Goldfish are messy.

Goldfish will generally grow to whatever size tank they are in. In a small bowl, a Goldfish may only grow to three inches. However, this will shorten their life span and may cause growth defects. In large ponds a Goldfish may grow up to two feet.

Feeding

If allowed to eat their fill, Goldfish will overeat to obesity. Keep in mind that a Goldfish's stomach is normally only slightly larger than its eye. Feed only enough to fill about "1 1\2 eyes." These fish like to nibble on plants, so keep them supplied with a kind they cannot pick to pieces. Anarchis is a good plant for Goldfish. Feed these fish a variety of flake foods and live foods. Feeding your Goldfish the same flake food day in and day out simply won't keep them healthy.

Water Chemistry

These popular fish should always be kept in water that has been aged at least 24 hours. Goldfish are sensitive to extremes of acid or alkaline pH, so neutral is recommended. Heaters are not needed, as Goldfish do best at room temperature. In outdoor ponds the ice may be allowed to freeze and the goldfish will survive through the winter. Higher temperatures will encourage infections and disease.

Breeding

Breeding your Goldfish is not a difficult task. Provide a large aquarium and keep the temperature around 72 degrees F is you wish to have the fish spawn. Provide bunched plants and a neutral pH. With any luck a pair will form and lay eggs which will hatch in under a week. The fry should be raised on small live foods and will be brown in color for up to a year before they finally develop their trademark golden scales.

More

Goldfish can become territorial. A newcomer placed where others have become established may get all of its fins nipped off or be chased to death. All of the Goldfish that co-inhabit each tank should be placed together within one month, before the territories are too firmly established. It may also help to rearrange any decorations when adding a new fish, that way the current fish won't feel as though it's 'home sweet home' to him.

Placed in outdoor ponds, Goldfish do quite well, existing on insects, algae, water plants, or the food you supply them. Goldfish are usually fine by themselves in aquariums, but in large pools they do much better in schools.

Despite their great variety of color and form, all Goldfish belong to the same species - Carassius auratus. Some of the available forms of Goldfish are the Comet, Lionhead, Veiltail, Celestial, Telescope, and Fantail. Most have long fins that may be nipped by others. All of these varieties were developed by the Chinese or Japanese except the Comet. Its origin is America.