The Common goldfish is the type most often kept in garden pools and cold water aquariums, but there is also a wide range of fancy goldfish available. These have exaggerated fins and body shapes, and there is some colour variation, but all tend to be more delicate and shorter lived than the hardy Common goldfish from which they derive.
ACQUIRING A GOLDFISH
Goldfish are usually sold in a plastic bag, from which it can be dangerous to tip them directly into a pond or tank. If the opened bag is floated on the surface for about 10 minutes until the water temperatures have evened up, then it is safe to empty out the fish. However, it can be more harmful to leave them in the bag if it is too small.
Young goldfish are a dull khaki colour, and do not show the full adult colouration until they are one year old.
As gregarious creatures, goldfish should be housed together in small shoals rather than kept singly.
Most of the time it is convenient to feed goldfish on dried, packeted food, but this should be supplemented when possible, with chopped lettuce and such freshwater invertebrates as Daphnia, Gammarus, and Tubifex worms, all available in frozen form from pet shops.
As coldblooded animals, fish are only active enough to feed well when they are warm. In summer they may need two meals a day; in winter perhaps only one meal on alternate days. Providing more than they can finish in about a quarter of an hour merely fouls the water with decaying matter.
A feeding ring in a tank keeps food from spreading across the entire surface of the water.
Fish kept in an established pond, with water plants and flourishing freshwater life, need no extra feeding.
Ideally, Common goldfish and all the hardy fancy varieties, such as Comet, London Shubunkin and visibly scaled Fantails should be kept in a garden pool all year. Other successful fish in ponds are Golden Rudd and Golden Orfe.
In autumn, cover the pond with a net to prevent it becoming choked with fallen leaves. Avoid smashing any ice that forms in freezing weather as the fish beneath will usually survive unless disturbed by shock waves. It is possible to float planks and balls on the surface at night and remove them in the day to open up air holes.
If fish are to survive under the ice, the pond must be 1rn (3 ft) deep in part. A pond of varying depth will enable a variety of plants to grow, and a shallow margin which warms up quickly in springtime will encourage the fish to spawn.
Small specimens of Common goldfish and the more delicate fancy varieties, such as Veiltail, Black Moor and Bristol Shubunkin, need to be kept in a tank. Big aquariums are costly, but a large surface area is of paramount importance.
Tanks may be furnished with gravel and a few smooth rocks, but most important are the plants that provide both shade and green food for the fish. Suitable plants for cold-water tanks include Canadian pond-weed, horn-wort, curly pondweed, and water milfoil.
A ventilated cover will help keep dust off the surface and keep the fish safe. It may house a light that will encourage the plants to thrive if left on 8-10 hours a day.
As fish have no eyelids, avoid subjecting them to the direct rays of the sun in summer. The tank can be shaded by a paper frieze or by painting part of the exterior dark green.