Salmon spawn on beds of fine gravel, in shallow parts of rivers, such as are used for the same purpose by trout. Some beds of this kind, in salmon-frequented rivers, have been notable from time immemorial as favorite spawning-places; and large numbers of fish, both the salmon and its congeners, deposit their spawn, in them every year. Time spawning female approaches the bed, attended by at least one male fish, sometimes by more than one, in which case fierce combats ensue; she makes a furrow in the gravel with her tail, and deposits her spawn in it, on which the male afterward pours the vivi fying milt. It was formerly believed that the furrow was in part made by the snout of the fish, and to this the snout of the male at the spawning season was supposed to be particularly adapted; but it has been found by observation that the snout is not used in this work. The eggs, when deposited and vivified, are covered by the action of the tail of the female; the male doing nothing but depositing his milt, and fighting with any other of his sex that may attempt to dispute his place.
The time occupied by a female salmon in spawning is from three to twelve days. After spawning the salmon generally soon descends to the sea. The descending kelts are very ravenous, and therefore a great annoyance to anglers who desire to take none but clean fish, and must return the kelts to the water.
The eggs deposited in the spawning bed are liable to be devoured by trouts and other fishes, which are ever ready, and by insect larwe of many kinds, which work their way even through the gravel; ducks and other waterfowl also search there for their food; and sometimes a flood changes the bed so much as either to sweep away the eggs, or to overlay them with gravel to a depth where they are never hatched, or from which the young can never emerge. The number of eggs hatched in ordinary circumstances must be small in proportion to the number deposited, and by far the greater part of the fry perish before the time of descent to the sea.
In from thirty to sixty days after the deposition of the eggs in the spawning bed they begin to show signs of life, and the eyes appear as small specks. The time which elapses before the egg is hatched varies according to the temperature of the water, and therefore is generally shorter in England than in Scotland, 140 days being sometimes requisite in cold climates and late springs; while it has been found that in a constant temperature of 44° F. sixty days are enough, and in a higher temperature eggs have been hatched even in thirty days. A temperature above 70° F. is, however, fatal to them. Salmon eggs are easily hatched in an aquarium, in which p•oper care is taken to pre vent stagnation of the water, so that the conditions may resemble those of a lied of gravel in a running stream, and many interesting observations have thus been made by Mr. Frank Bucklaud on the development of the young salmon, of which the results have from time to time been given to the world through the columns of the Field news paper, and his excellent work on ne young fish lies coiled up in tha egg, which it finally bursts in its struggles 10 be free, and it issues with a conical bag (umbilical vesicle) suspended under the belly, containing the red yolk of the egg and oil globules, which afford it nourishment during the first five or six weeks. The mouth is at first very imperfectly developed, as are the
fins, and the whole body has a shape very different from what it is seen to assume, and is very delicate, and almost transparent. The slightest injury is fatal. The length, at first, is about five-eighths of an inch. About the seventh or eighth week, the young salmon has changed into a well-formed little fish about an inch long, with forked tail, the color light brown, with nine or ten transverse dusky bars, which are also more or less distinctly visible in the young of other species of this genus, just as the young of many feline exhibit stripes or spots which disappear in their mature state. The fry, previously very, inactive, now begin to swim about, and seek food with great activity, and arc known as PARR or SAMLET, and also in some places by the names pink, brandling, and fingerling. The parr was formerly supposed to be a distinct species (S. salmalas), an opinion to which many anglers, eager to enjoy their summer holidays, and catching parr by scores with the artificial fly or worm when they can catch nothing else, have clung tena ciously, after it has been shown to the satisfaction of all naturalists that the parr is nothing else than the young salmon. The honor of proving this belongs to Mr. Shaw, of Drumlanrig, Dumfriesshire, whose observations and experiments, first made in 1831 36, we have not space to detail. They have, however, been fully confirmed at Lie sal mon-breeding ponds of Stormontfield, on the Tay.
It was long urged, to prove the parr a distinct species, that the male parr is very often found with the milt perfect, to which, however, it was replied that the female parr i.: almost never found with perfect roe. But the remarkable fact has now been abundantly proved that the male parr is capable of impregnating the roe of the female salmon, and thus a provision seems to be made in nature to prevent an otherwise possible loss of roe. And, indeed, ridiculous little parrs seem to be always ready at hand to perform this service during the combats of the great fish, or in their absence, Another remark able fact has been discovered, that some parrs descend to the sea in their first year, while others remain in the fresh water, and in the parr state, without much increase of size for another year, and a few even to the third year. At Stortnontfield it has been found that about one-half of the parrs migrate when a year old. No reason can be assigned for these things; the facts alone are known to us, and have but recently been e.tahlislied.