PISCES, the "Fishes," in astronomy, the twelfth sign of the zodiac, represented by two fishes tied together by their tails, and denoted by the symbol X . In Greek legend Aphrodite and Eros, while on the banks of the Euphrates, were surprised by Typhon, and sought safety by jumping into the water, where they were changed into two fishes. This fable, however, as in many other similar cases, is probably nothing more than an adaptation of an older Egyptian tale. The constellation contains only faint stars without any striking grouping.
Piscis australis or Austrinus, the southern fish, is a constellation of the southern hemisphere. It contains Fomalhaut, a star of the first magnitude.
Piscis vola:ts, the flying fish, is a constellation introduced by John Bayer in 1603. The name is now abbreviated to Volans. PISCICULTURE. The species of food-fish that can be kept successfully in ponds throughout their lives from egg to adult are exceedingly limited in number. The various breeds of gold fish and top-minnows (Cyprinodonts) are familiar examples and the carp is an example of food-fishes capable of similar domestication. In the United States the eastern brook trout and the black bass are almost as fully domesticated. Various other food-fishes, both marine and fresh-water, can be kept in ponds for longer or shorter periods, but refuse to breed, while in other cases the fry obtained from captive breeders will not develop. Consequently there are two main types of pisciculture : (I) the rearing in confinement to an edible stage of the young of domes ticated breeders; (2) the stocking of natural waters with eggs or fry from captured adults.
intensive methods have been applied to pond culture with remark able results in recent years.
In the United States some species of trout and chary have become so thoroughly domesticated that many commercial trout hatcheries have been established, some of them with a score of ponds heavily stocked with eastern brook trout (Salvelinus fon tinalis) sorted into different ponds according to size and fed usually on slaughter house offal in addition to such natural food as they may obtain. Under this system the trout grow twice or three times as fast as the wild ones, a growth of from 7 to I I in. during the first year being no exception. Some of the male fish are killed and sold before they are sexually mature; but most of the fish are kept until they reach sexual maturity in the second fall of their life at the age of 20 months and are then stripped and sold immediately thereafter.
Next in order of importance are the North American basses and sunfishes (family Centrarchidae), all of which make "nests." The most important members of the family are the largemouth (Aplites salmoides) and smallmouth (Micropterus dolomieu) black bass which are propagated in large numbers of State, national and private ponds. Artificial nest-boxes with bottoms covered with material suitable for the species are placed in the ponds, the fish spawn in them and the male guards the nests and schools of fry. The schools of young, usually numbering several thousand to the nest, are transferred to rearing ponds and fed on Japanese Daphnia raised in small separate ponds and on other food. Young bass are usually planted as fingerlings, 3 or 4 in. long or as yearlings. They could be raised for the market, but the cost would be prohibitive. In addition to the bass seven species of sunfishes are cultivated in the United States by similar, but simpler methods.