This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Information of the highest importance on the artificial propagation of fish was laid before the late meeting of the British Association. Experiments with salmon, made at Perth, Scotland, have been extremely successful. Three hundred boxes were laid down in twenty-five parallel rows, each box partly filled with clean gravel and pebbles. On the 23d of December, 1853, 300,000 ova were deposited in the boxes. On the 31st of March, 1854, the first ovum was observed to be hatched, and in April and May the greater portion had come to life, and were at large in the boxes; in June they were admitted into the pond, their average size being about an inch and a half in length. From their admission to the pond the fry were fed daily with boiled liver, rubbed small by the hand. By spring of the present year they had in-creased in size to the average of three and four inches in length. On the 2d of May a meeting of the Committee was held at the pond, to consider the expediency of detaining the fry for another year or allowing them to depart, but it was thought they had not assumed the migratory dress till the 19th, when the sluice communicating with the river Tay was opened, and every facility for egress afforded.
Contrary to expectation, none of the fry manifested any inclination to leave the pond until the 24th of May, when the larger and more mature of the smelts, after having held themselves detached from the others for several days, went off in a body. A series of similar emigrations took place until full half the fry had left the pond, and descended the sluice to the Tay. It has long been a subject of controversy whether the fry of the salmon assume the migratory dress in the second or third year of their existence. So favorable an opportunity of deciding the question as that afforded by this experiment, was not to be overlooked.
In order to test the matter in the fairest possible way, it was resolved to mark a portion of the smelts in such a manner that they might easily be detected when returning as grilse.' A temporary tank, into which the fish must necessarily descend, was constructed at the junction of the sluice with the Tay; and as the shoals successively left the pond, about one in every hundred was marked by the abscissionof ' the second dorsal fin. A greater number were marked on the 29th of May than on any other day, in all about 1200 or 1300. The result has proved highly satisfactory and curious. Within two months of their liberation, twenty-two of the young fish so marked when in the state of smelts on their way to the sea, have been, on their returning migration up the river, recaptured and carefully examined; the conclusions arrived at are most gratifying, and proved what has heretofore appeared almost incredible, the rapid growth of the young fish during their short sojourn in the salt water. Those taken first weighed 5 to 5 1/2 ft, then increasing progressively to 7 and 8 ft, whilst the one captured on the 31st of July weighed no less than 9 1/2 ft.
In all these fish the wound caused by marking was covered with a skin, and in some a coating of scales had formed over the part.
The experiment has afforded satisfactory proof that a portion at least of the fry of the salmon assume the migratory dress and descend to the sea shortly after the close of the first year of their existence; and what is far more important in a practical point of view, it has also demonstrated the practicability of rearing salmon of marketable value within twenty months of the deposition of the ova.
There can be no doubt that the quantity of salmon (as well as other fish,) may be enormously increased by the artificial breeding process, and we regard the experiments of great importance. At Cleveland, Ohio, success has attended the first experiments of Dr. Garlick and his coadjutor, who may do a vast deal for their fellow men by fully populating our western lakes. In the salmon regions, east and west, the subject deserves attention. And there is little doubt that in neighboring rivers, where salmon are now unknown, they might be thus successfully introduced. How much more useful would it be if some of our sportsmen would take up the subject, instead of devoting their hearts, bodies, and time to the poor enjoyment of shooting useful birds !
Cleveland (Ohio) has the honor of producing an original work of very great importance to this country, on a subject that has frequently been noticed in the Horticulturist. The title is: "A Treatise on the Artificial Propagation of Certain Kinds of Fish. By Theodatus Garlick, M. D." In conjunction with Dr. Ackley, the experiments hare been carried on till a treatise, every way worthy of the subject, is presented to the American public; so plain in its statements, that no one can misunderstand them. This handsome octavo deserves to be very popular, and that its topics may be practically studied, must be the wish of every lover of his country.