PISCICULTURE, or FISH-CULTURE, the breeding and rearing of fishes, in order to the increase of the supply for food. Hitherto it has been almost entirely limited to fresh. water fishes; nothing having been done as to sea-fishes but by legislation—chiefly in the case of the herring—to prevent the destruction of the very young fish, and that not, apparently, to much advantage. Ponds for sea-fishes have, indeed, been sometimes constructed, advantage being taken of natural circumstances favorable for the purpose. The ancient Romans had such ponds, and some have been made on different parts of the British coast, fishes being caught in the open sea and placed in them to be fed and fat tened for the table. Such ponds, however, are of little real utility. That the Romans succeeded in keeping sea-fishes in fresh-water ponds, as has been asserted, must be regarded as mere fable, 'or as an exaggeration, founded on the power which a few fishes have of adapting themselves both to fresh and salt water. But it may be doubted if in modern times sufficient advantage has been taken of this power.
Ponds for fresh-water fishes have been common from a very remote antiquity. It appears from Isaiah, xix. 10, that they were used in ancient Egypt. In the times of Roman luxury almost every wealthy citizen had fish-ponds. The Chinese have long bestowed more attention on pisciculture than any other nation, and with them. it is truly a branch of economy, tending to the increase of the supply of food and of the national wealth; not merely, as it seems to have been among the Romans, an appliance of the lux ury of the gas at. In some countries of modern Europe this branch of piscicultnre is also prosecuted to it very considerable extent, particularly in Germany cud SweLen, and of late years in France, in order to the supply of fish for the market. In Britain it has never been systematically prosecuted, or for any important purpose; the country seats of the nobility and gentry being, indeed, generally provided with fish-ponds, but in most cases rather as ornamental waters than for use. In the northern parts of Britain trout, perch, and pike are almost the only fish kept in ponds; in England they are often stocked with carp and tench, and are turned to much better account than in Scotland. In Germany, ponds carefully attended to are found very productive and remunerative. There can be no doubt that in Britain, also, many a piece of land at pres ent very worthless, might easily be converted into a pond, and made to yield large quan tities of excellent fish; but such it thing seems almost never to be thought of.
In the construction of ponds, or stews. for tish, it is recommended to have, if possible, a succession of three pon4on the same rivulet, with sluices, by which they can be dried, so that the fish may be easily taken when required, the different ponds being iu part intended for fish of different ages. But all this must be very much regulated by local circumstances. It is of more importance to note that the margins should he shallow, so that there may be abundance of reeds and other water plants, and that only a small part of the pond should be too deep for the growth of pond-weeds (poly mullefo n). Much depends upon the soil of the neighborhood as to the supply of food, and consequently the growth of fish and productiveness of the pond. A stony bottom is very advantageous to perch and trout ponds; and in designing these, care should be taken to provide places of shelter for the fish, more especially if the pond be it shallow one, as trout and perch are easily killed by the glare of the sunshine. Ponds for' pike must be larger than is necessary for any other fish known to British pisciculture; an extent of at least six acres is desirable. A nursery for minnows may be.established with great advantage in connec tion with a fish-pond, a3 they afford most acceptable food to perch, pike, and trout. But in a pond where carp and teach are expected to spawn, the presence of minnows is very undesirable. It is often impossible to provide a pond with a place suitable for the spawning of trout, for which a gravelly stream with a quick current is necessary; but for perch, pike, carp, or tench, the pond itself is sufficient, and the stock, once intro duced, is kept up without replenishing. Indeed, it is recommended that a pond stocked with carp should disc be stocked with pike, that the excessive multiplication of the carp may he checked, which would otherwise prevent the fish from growing rapidly or to a good size. Private ponds and stews in which country gentlemen breed fish for the use of their own tables, as well as similar places attached to monasteries and other religious edifices, in which fish were grown for fast-day uses, were at one time common enough throughout Great Britain and Ireland. It is probable that some of our rarest fishes were introduced into this country during the old monastic times, such as the Lochleven trout, the vendace, etc.