Tropical Fish is a term applied to any one of a great number of fishes which may be kept in small standing aquariums, usually in homes. Such fish originate in small streams and ponds in many tropical and subtropical areas of the world, with the greatest number coming from the basin of the Amazon, India, the Malay Peninsula, and the East Indian Archipelago. Lesser numbers come from the waters of Africa, especially the Nile and the Congo basins, from tropical South America other than the Amazon area, and from some of the West Indian islands, not because there is necessarily a lesser number of suitable fishes in these places, but because collecting and transportation have not been developed to so great an extent as in the first-named areas.
The fishes are kept as a hobby by millions of people in all civilized countries, supplementing and actually supplanting the keeping of goldfish, and a large industry has sprung up around them. This includes the collecting in the wild, transportation, the domestic and commercial breeding of suitable species, and the wholesale and retail distribution of them, as well as of suitable tanks and equipment, a subsidiary business which runs into millions of dollars in the United States. A hobby of similar magnitude, with its auxiliary businesses, has developed in England and Germany, with lesser activity in other European countries, South Africa, Australia, and New Zealand.
A great number of clubs of fanciers and hobbyists have been established and several magazines are supported, as well as a fairly large literature devoted to descriptions of the fishes, and methods of keeping them.
Raising Tropical Fishes
Most tropical fish are relatively hardy and easy to raise, and they all require about the same equipment, feeding, and care. There are, however, a few species that require special care.
The basic materials needed for keeping tropical fishes are a tank or other container, a heater, gravel, and water plants. If the aquarium is kept simple, these materials are relatively inexpensive to buy.
All pet stores sell dried fish foods that provide an almost perfectly balanced diet for most fishes. Fish should also be given an occasional treat of live food, which can be bought or collected by the aquarium owner. One of the best live foods for tropical fish is brine shrimps, which are available live or frozen. The eggs of brine shrimps are also sold for hatching and raising at home, and newborn brine shrimps are especially good food for very young fish.
Another popular live food is Daphnia, which are tiny crustaceans that can be gathered from around the edges of small lakes and ponds. They also can be purchased live or frozen. Other valuable live foods include tubifex worms, garden worms, and wingless fruit flies.
Tropical fishes are usually fed once a day. Only as much food as the fish can eat in about ten minutes should be put in the tank, because overfeeding is a major killer of tropical fishes.
The easiest tropical fishes to breed are the live-bearers. If kept with a male of the same species for a short time, the female is almost certain to become pregnant. Live-bearers usually bear young every three to five weeks. When the female is ready to give birth, its belly bulges noticeably. At this time it should be moved to a separate tank containing a number of plants. The young, which are born one or two at a time, dart into the plants and hide so that the mother cannot eat them. After the young are born, the mother is returned to the original tank. Unlike live-bearers, egg layers are difficult to breed because each species requires particular, controlled conditions.
With moderate care, tropical fishes rarely become ill. Their only common disease is ich, or white spot, caused by a tiny parasitic animal that imbeds itself in the fish's skin. White spots appear on the fins and belly, and the fish scratches itself against hard surfaces. The disease may infect and kill all the fish in a tank. Chemicals can be added to the water to destroy the parasites.