The common goldfish (Carassius auratus) are the patriarchs of ornamental fish for, excepting the tropicals, these are the fish from which most of the fancy breeds have been developed. A healthy specimen has a short, wide head, small mouth, bright eyes, a long, flat body arched in both belly and back, with a stiff dorsal fin rising from the middle of the back arch. The scales are bright, the tail stiff and moderately forked, and the fins stiff and of moderate size.

The common goldfish is hardier than most of its descendants, remains healthy under a wider range of temperatures, and will even survive a few hours out of water, if kept moist. It breeds prolifically, and it will eat practically anything. It is a favorite for its hardy nature and because it can be trained to eat from the hand. The various colorations sometimes go by special names. The silvery albinos are called Pearls. Those which color up to yellow instead of red-gold are called Canaries. Those with red-gold scales, with patches of black, are frequently sold as Orioles.

   The Comet was developed in the late 1880's, first by accident and later by selective breeding, in the ponds of the Fish Commission in Washington, D.C. The body is more elongated and there is much more elaborate fin and tail development than in the parent.

The extensive fins and tail make the Comet one of the fastest and most graceful of all goldfish. It swims with smooth, darting movements often too fast for the eye to follow. It is particularly active in the spring, when it frequently will leap out of the water. For this reason, aquariums containing Comets should be covered with a screen during the fish's lively season. Like the parent species, the Comet is very hardy and simple to feed.

   Another strain of the common goldfish, and a beautiful addition to any pool, is the Fantail, whose movements are as slow, deliberate, and stately as the Comet's are swift. The appearance of any Fantail in a water garden is a beautiful sight, but serious fanciers often prefer the type with double tails and double anal fins. A tail joined at the top is called a web-tail and looked upon as a blemish by those who breed fish for show competition. A single instead of a double anal fin is also considered undesirable. To all but the experts, one type is as pretty as another.