Rensselaer Union, Volume 8, Number 2, Rensselaer, Jasper County, 30 September 1875 — Fish Culture. [ARTICLE]

Fish Culture.

f The results so far attained in this country in the artificial culture of fish are eminently satisfactory, and the efforts made by the various fisheries commissions to increase the supply of food for the people are worthy of all commendation. Naturally, there exists a lively public curiosity to know the processes of fish-culture and information with regard to its history, its principles and its methods is heartily welcomed. In response to- this general demand, Mr. Robert B. Roosevelt, Fish Commissioner of the State of New York, has given a public lecture oil pisciculture, in which he very fully considers the subject in all its aspects. The lecture is very long and we must be content with indicating only a few of its points. There are, he said, two divisions 01 fish in our conn, try which are subjects of fish-culture, namely the Salmonidcef or salmon-tribe, and the Alosidce, or shad-tribe. Under the former head are included the salmon, the trout, the salmon-trout (or,lake-trout), the white-fish and the California salmon. The Alosidce are represented in pisciculture only by the shad, as yet. The first point in fish-culture is to obfiuntEe spawningifishinproper condition. In the Salmonidce, the eggs, when in a perfectly ripe condition, lie free in the abdomen and may be extruded by gentle pressure. They are caught as they fall in a basin and are vitalized by coming in contact with the milt from the males. Formerly, the practice obtained of having this basin full of water, it being supposed that this arrangement more nearly reproduced the conditions ; but subsequent discoveries led to a change of this method. The eggs are fertilized by the... spermatozoa of the milt entering through the micropyle and taking up board and lodging within. It was ascertained, however, in practice, that these spermatozoa are not fond of water, and, although very active when first emitted, soon drowned. They retain their vitality much longer when dropped among the egg's in a comparatively dry state, and this is the method universally pursued at present. As soon as the operation is completed the eggs are placed * in hatching-troughs. These are made of various materials, but are simply long, narrow boxes,- say twelve feet long by eighteen inches wide, and subdivided into apartments to keep the eggs from crowding on one another. Cold spring water, which has been carefully filtered by passing through several flannel screens, comes in at the head of these troughs, passes over the eggs in one compartment after another and escapes at the lower end. By this means the greatest ‘dangers to the'life of the embryo are avoid: ed. Sediment and confervce cannot pass the screens, insects are kept out altogether, and ducks and eels are disappointed of their prey. The eggs require about two months to hatch, with the water at. the temperature of forty-five degrees. They demand constant care and attention, for i’s one egg dies or becomes diseaseu it contaminates its neighbors. The ad rance of the process is, however, Soon visible in the egg, either to the human eye or under the microscope. At last the pisciculturist will have evidence of his labors being successful. Some morning on going to his troughs he will notice broken egg-shells in the v\*at ei*, - and- on closer inspection' wi 11 observe wiggling nondescripts on the bottom, neither like fish nor eggs, but compounded of both. When they once begin to appear they come in thousands, in millions, in myriads. The young need more water at this time, but require less care; yet still they must be watched. The young fish may soon be turned loose into the stream. If he is a salmon after a few months? preparation to strengthen his sinews and test his power he goes down to the sea, there to dwell, and feed and grow, gaining wonderfully in size, drawing his sustenance 'from the exhaustless storehouse of the world, and coming back to man in a few months a magnificent embodiment of strcyigth and beauty, bringing to the lord of the universe five or ten pounds of as delicious food as ever delighted a gourmand’s palate, or satisfied a hungry man’s stomach. If he is only a-trout, a younger brother of the glorious family'of Salmonidoe, he will lurk about the bottom of some pond, or graze the pebbly mountainbrook, and struggle up to a half-pound or more before twelve months shall have rolled dver his head.— Popular Science Monthly.