SALMON-TROUT.
Known also as the Sea-trout, and in Ireland as the White Trout.
Closely resembling the true salmon in habits and appearance, and sometimes rivalling it even in size, are two kinds of sea-trout—the Salmon-trout, greatly prized both for its sporting qualities and for the excellence of its flesh, and the Bull-trout, a very inferior fish in both respects. Bull-trout are not infrequently taken in the Tay weighing upwards of 40 lbs.
The Pacific Ocean has its counterpart to the Atlantic salmon and sea-trout in several closely allied species, whereof the Quinnat and the Steelhead are the most notable. These ascend the great rivers of Western North America in prodigious shoals, penetrating more than 2,000 miles inland to deposit their spawn. Few of these fish survive to return to the sea. In their emaciated condition they succumb to exhaustion and starvation; their corpses, piled to the height of several feet, line the banks of the river for miles, and contribute nothing to the traveller's comfort. Although Pacific salmon are of no value to the sportsman, as they are said to refuse any bait in fresh-water, yet they are the staple of an important trade, tens of thousands of tons being taken and canned for export.
If we could peer far enough back into the course of time, we should no doubt be able to identify a common stock from which all the Salmon Family are descended. That they are all natives of fresh-water is proved by the fact that they cannot reproduce their kind in the sea. Those that resort to the ocean for food must be the descendants of vigorous, roving members of the family, which, having to choose between starvation and migration, braved the perils of travel, and became so much altered in constitution by the liberal diet they found as to establish themselves as separate species.
Among the stay-at-homes there are many interesting and beautiful fishes. None of them exhibit the variable nature of the family more than the common Brook-trout of British waters, and not long since men of science dignified each of these varieties by a separate title, treating them as distinct species. However, experiment and observation have now led to the almost unanimous conclusion that the pygmy denizens of some hungry Highland burn, whereof the weight must be reckoned in fractions of ounces, are of precisely the same species as the lordly trout of deep lakes, which sometimes scales as much as 25 lbs., and as all the other innumerable varieties, such as the trout of the Thames, of the English chalk-streams, and of the Irish loughs. The quality of the soil affects the food-supply, which in turn regulates the size and appearance of the fish. Moreover, Nature seems indifferent to the number of individuals composing the population which the water is to sustain. If there are no pike, and spawning-ground is abundant, there will be many and small fish; if the contrary is the case, there will be few and large ones; the aggregate weight per acre of water will remain the same, proportioned to the food-supply. The American equivalent of the British brook-trout is the Rainbow-trout, a beautiful creature which has lately been widely distributed in European waters. What is known as the brook-trout in America really belongs to the Char group, fish of the Salmon Family, closely resembling trout, but distinguished from them by extraordinary brilliancy of colour. Common trout, like salmon, lose all their beauty as the spawning-season approaches. Char, on the other hand, take gaudy colouring at that time, the whole of the under-parts becoming clear red or flame-colour. Unlike trout, British char never enter rivers, but spawn in lakes. In Norway, however, char descend to the sea. The distribution of char is indeed mysterious, nor has any explanation been offered why they inhabit certain waters, while other lakes in the neighbourhood, apparently equally suitable, contain none.
The Grayling is an elegant member of the Salmon Family, and a deserved favourite with fly-fishers. Instead of the golden tints and scarlet spots of the brook-trout, this fish displays the silvery colouring of the salmon-trout. It is not at all uncommon to meet with grayling in the chalk-streams of Southern England weighing 3 lbs. and upwards.
The Powan is the type of another large group of salmon-like fishes, inhabiting lakes in the temperate and subarctic regions of both hemispheres. There are four species in Great Britain, among which may be mentioned the mysterious Vendace of Lochmaben, unknown to exist elsewhere.
Photo by W. Reid] [Wishaw, N.B.