The Game Fish, of the Northern States and British Provinces / With an account of the salmon and sea-trout fishing of Canada and New Brunswick, together with simple directions for tying artificial flies, etc., etc.

by Robert Barnwell Roosevelt

Such a result is no trivial injury to the community. The vast extent of these stretches of water are but little understood by the people at large. There are in the State of New York alone six hundred and forty-seven lakes, with an area of four hundred and sixty-six thousand four hundred and fifty-seven acres, besides countless smaller ponds, and miles of river and stream. Fully a quarter of a million of acres of the public patrimony are thus allowed to go to ruin and decay for the want of proper knowledge and a little care. It would have been easy to have protected them; it is a far more serious matter to restore their ancient productiveness.

Trout are found in all rivers in which salmon can hatch their young, but as they are not necessarily migratory, they often dwell where salmon cannot. Trout require a temperature of water never exceeding seventy degrees. At sixty-eight degrees they begin to suffer; at seventy degrees, unless there is a strong and broken current to give life to the water, they die rapidly, and not one will survive a temperature of seventy-five degrees. It is simply manifest then that the Southern and Western rivers are not generally inhabitable for trout or salmon. Trout may be found in the head waters of such as rise in the Alleghany range of mountains, but salmon can exist in none of them. So also with the sluggish, muddy rivers of Ohio, Indiana, Illinois, Missouri and the vast central region of our continent. Throughout the entire section between the Alleghanies and Lake Superior and the Northern Mississippi, except in Northern Michigan, no trout are found, and then again not till you come to the Rocky Mountains. Trout and salmon, except in the matter of migration, are similar in their habits. The eggs of either may be hatched in the same boxes, with the same water, in about the same time, and under the same treatment.

When we speak of the temperature of a pond or river, allowance must be made for springs to which fish will have recourse, precisely as men perishing in a room for air, would put their mouths to a knot hole to breathe. If there are springs enough, trout will live in waters the body of which reaches a higher temperature than seventy-five. So also, a strong rush of water as with a cataract or rapids, will enable them to endure greater heat than they could otherwise stand. Still it is not safe to subject any of the eastern salmon or trout family to a permanent temperature higher than sixty-five degrees. Salmon trout suffer most and die the first, at least when they are confined in a limited space with a small flow of water.

The first point in fish culture is to obtain the spawning fish in proper condition, for if the eggs are not mature or ripe, as it is usually called, not only are they useless, but the effort to extract them will kill the parent. Fish breeders, who make the cultivation of trout a business, and there are many in this country, keep on hand in suitable ponds a supply of large fish. These are taken from the rivers, which they are ascending to spawn, and are kept over from year to year. Connected with the ponds in which they are confined, is a raceway, or long narrow trough which has a gravelled bottom, is covered with boards to exclude intrusive eyes, and in every way is made as attractive a nesting spot to the fish as possible. Into this they will proceed of themselves when they are ready to perform their allotted act of reproduction, and the breeder awaiting his opportunity, places a net at the mouth of the race and frightening them in, selects such as are ready for manipulation.

When in a perfectly ripe condition, the eggs lie free in the ovaries in the abdomen, and may be extruded by a gentle pressure downward along the sides of the fish. They are caught in a basin and are vitalized by coming in contact with the milt from the males, for the fish, male and female, are stripped indiscriminately into one common receptacle. Formerly, the practice obtained of having this basin full of water, under the idea that such arrangement more nearly reproduced the natural conditions, but subsequent discoveries led to a change of this method. The ova are fertilized by the spermatozoa of the milt entering through the micropyle, and it was ascertained that these spermatozoa, little tadpoles as they appear to be under the microscope, were not fond of water, and although very active when first emitted, soon perished in it. They retained their vitality much longer when dropped among the ova in a comparatively dry state, and this is the method universally pursued at present. The result of the change was very great; on the earlier plan not more than one egg in three or four was vitalized, whereas now, fully ninety-eight per cent. are made capable of producing young.

In selecting a place for trout hatching, it is essential to have one where the water is at an even low temperature, near to the springs if possible, and where there is absolute security from muddy drainage or overflow from rains. The shape of ponds is not important, if the water is abundant and cold enough.

It is best, if possible, to have ponds so arranged that they can be entirely drained. This is necessary, sometimes, for cleaning or repairing them, and changing the fish from one pond to another. If the slope of the ground is sufficient to permit of such an arrangement, it will often save much labor in pumping or bailing. The drain pipe may be of pump logs, tile or pipe of any kind, and should be fixed in the lowest part of the bottom, or as near it as the level of the ground will allow. Still better would be a regular flume reaching from the bottom of the pond to the top. A bulkhead may be put in to raise the water as high as may be required, and a wire screen the whole size of the flume set a short distance in front of the bulkhead. This large screen has an additional advantage, as the larger the screen the less liable it is to clog up with leaves and moss, and the greater will be the volume of water passing through it.

Screens may be made of common wire painted with tar, or of galvanized iron wire. The last is the best, as it will last longest in proportion to its cost. The screens for keeping the small fry should be of fourteen threads to the inch, and for one year old fish five or six threads to the inch. Incline the screens at an angle of forty-five degrees, the top being farthest down stream. By inclining the screens in this manner, a greater surface is exposed to the water, than if they were placed perpendicularly. The sockets should be so made that the screens will fit tightly, and yet be easily taken out to clean.

A very good screen for two and three-year-olds can be made from strips of lath, planed, and nailed to a strong frame, with quarter-inch openings between them. Or, what is better, the slats should be at least four inches wide, so that if a leaf strikes against them, it will catch without obstructing the flow of water and lie flat against a single slat, or, if it reaches over the edge, it will be carried through by the current striking upon one end. It cannot lap around the slat as it would if it were smaller. As for the width of the slats from one another, the point to be guarded against is the fish running their heads through far enough to strike their eyes which will produce blindness. The distance they are to be apart will depend consequently, mainly on the size of the heads of the fish, and as fish grow at different rates of speed, it will not do to go merely by their age, but for fair sized fish an opening of about five-eighths of an inch will answer. This refers to the upper screen, the lower screen, that at the foot of the pond, may be larger, as the fish are more cautious about descending where they cannot see their way.

The proportion of males to females in a pond should be about one-half. Not so many are necessary to fecundate the eggs, and it would be an advantage in one way to have fewer, since then there would not be so much fighting in choosing partners, and as all the females do not spawn at once, one male would be enough to serve several females; but, on the other hand, the males seem to run out of milt before the females get through laying their eggs, and towards the close of the season it is often difficult to obtain males with milt enough to fecundate the eggs; so that it seems better to have in the pond an equal number of males and females, thereby giving more chance of saving some of the milt till the last of the season. The males are very amorous, and will pair again and again. It very often happens, that some of them die from the exhausting effects of the season.