The greatest improvement in pisciculture, and a most important branch of it, to which the term is often restricted, is the breeding of fish in artificial breeding places, from which not only ponds, but rivers, may be stocked; or the art of fecund sting and hatching fish-eggs, and feeding and protecting the young animals till they are of an age to secure their own food and protect themselves from their numerous enemies.
Modern pisciculture is the revival of an old art well known to the ancient Italians. but which had fallen into abeyance for a number of centuries. The art of breeding aid fattening fish was practiced by the luxurious Romans, and many stories are told shout the fanciful flavors which were imparted to such pet fishes as were chosen for the sump tuous banquets of Lucullns, Sergius Orata, and others. The art had doubtless been bor rowed from the ingenious Chinese, who are nivIerstood to have practiced the art of col lecting fish-eggs and nursing young fish from a very early period. Fish forms to the Chinese a most important article of diet; and, from the extent of the water-territory of China, and the quantities that can be cultivated, it is very cheap. The plan adopted for procuring fish-eggs in China is to skim off the impregnated ova from the surface of the great rivers at the spawning-season, which are sold for the purpcise of being batched in canals, paddy-fields, etc.; and all that is necessary to insure a large growth of fish is simply to throw into the water a few yolks of eggs, by which means an incredible quan tity of the young fry is saved from destruction, as a large percentage of the young of all fish die for want of food. Although all kinds of fish are enormously fecnnti, it is well known to naturalists that only a small percentage of the eggs ever come to life, arid of the young fish, very few ever reach the table as food. So many of the eggs are destroyed by various influences, and so many likewise escape impregnation, that if we are to keep up our fish supplies, pisciculture, or protected breeding, becomes absolutely necessary.
Commercial pisciculture, as at present carried on, owes its origin to the French, the art having been first put in practice by M. Remy, a poor fisherman who gained a living by catching tish in the streams of La Bresse in the 'Vosges. This re-discovery of the lost art of fish.breeding is understood to have been quite accidental on the part of Remy, although it is thought by some zealous Scotsmen that the Frenchman must have heard of the experiments of Mr. Shaw of Drumlanrig, who, for a few years previous to Remy's discovery, had been trying to solve some problems in the natural history of the salmon by means of the artificial system. The art had also been parzially revived in Germany about the middle of last century by a gentleman of the name of Jacobi, who practiced the artificial breeding of trout. Whether or not heard of • either of these experimenters, it is certain that to him we owe the revival of the art in its larger or commercial sense; the others only used it as an adjunct to their study of the natural history of fishes.
It was the great waste of eggs incidental to the natural system of fish-brecding that led Remy, about 1842, in conjunction with Gehin, a coadjutor whom be assumed as it, partner, to try what he could do in the way of repeopling the fish-sti cams of his native! district. His plan being at once successful, attracted the favorable notice of many of
the French sarans, and led to rewards and preferment for Remy; the new art was besides taken under the protection of the government. At Huningue, in Alsace, on the Rhine, a gigantic fish-nursery and egg-depot for the supply of eggs, and the dissemina tion of the art, was erected some years ago. Since the cession of Alsace to Germany, the operations of the establishment at Huningue (now known as HUningen) have been conducted on a still larger scale by a German association.
The course of business at Huningue is as follows: The eggs are chiefly brought from the streams of Switzerland and Germany, and embrace those of the common trout, as well as the Rhine and Danube salmon, and the tender chary or ombre chevalier. People are appointed to capture gravid fish of these various kinds, and having done so, to communicate the fact to Huningue. An expert is at once sent to deprive these fishes of their spawn, and bring it to the breeding or resting-boxes, where it is carefully tended till it is ready to be dispatched to some district in want of it. It is, of course, much more convenient to send the eggs than the young fish, as. the former. nicely packed among wet moss in little boxes, can be carried to a distance with greater facility. The mode of artificially spawning a salmon is as follows: It should, of course, be ascer tained that the spawn is in a perfectly matured state, and that being the case, the salmon is held under water in a large tub, while the hand is gently passe(' along its abdomen, when, if the ova be ripe, the eggs will flow out like so many peas. The eggs are then carefully washed, and the water is poured off. The male salmon i; then handled in a similar way, when the contact of the milt immediately changes the eggs into a -brilliant pink color. After being again washed, they may be ladled out into the breeding-boxes, and left to come to life in due season. The period occupied in hatching is different in different climates. At Stormontfield, where the eggs have no shelter, the usual period is about 135 days; but salmon ova have been known to burst in about half that period, and to yield very healthy fish. Great care is of course necessary in handling the ova. The eggs manipulated at Huningue are all carefully examined on their arrival, when the bad ones arc thrown out, and those that are good are counted and entered in a record. The ova are watched with great care, and from day to day all that become addled are removed. The, applications for eggs, both from individuals and associations, are always a great deal tnorc numerous than can be supplied; and before second applications can be entertained, it is necessary for the parties to give a detailed account of how their former efforts succeeded. It may be interesting to note, as regards the cost of pisciculture at Huningue, that the most expensive fish is the ombre chevalier. Of some species, as many as CO or 70 per cent of the eggs are lost. The general calculation, however, is 12 living fish for a penny.