The limits of this work will not permit a minute and detailed description of all the details of fish culture. For an exhaustive treatise on that subject, the reader is referred to a book called “Fish-Hatching and Fish-Catching,” which contains in a practical form all that was known up to the time it was written. But general rules are given in this chapter which will enable the novice, the farmer, the gentleman country resident and happy owner of a trout stream, to largely increase his revenue and his pleasure by recruiting his preserves and making waste waters, if not to blossom as roses, to produce a yield of food for the table and sport for the rod.
We shall turn first our attention to trout and salmon culture, which are so nearly identical that they may be studied together. There are at present no natural salmon rivers in this country except in Maine, Oregon and California, the efforts to restock the Merrimac and the Connecticut having only achieved partial success. It is the present opinion of the writer that salmon were never regular visitors of the Hudson River, or that if they were indigenous to it, it was only in very limited numbers. This opinion was formed from a study of the waters which are not well adapted to the propagation of that class of fishes. Further south than New York, salmon were probably never known to go at all.
Under the head of Salmon, may be included the salmon, the trout, the salmon-trout, otherwise called lake-trout, the whitefish, the grayling, the fresh-water herring or cisco, and California brook-trout, and the California salmon. The scientific names of these are, salmo salar, salmo fontinalis, salmo confinis, salmo amethystus, coregonus albus, thymallus signifer, and salmo quinnat. These are all essentially alike in their mode of culture, the differences being so inconsiderable that they may be disregarded for the present. We shall speak of one for the whole, only occasionally pointing out such individualities as may be necessary.
They spawn in the autumn and winter, with the exception of the California salmon, which is earlier, and spawns in summer and first of autumn; the grayling, a fish of the same race, which has lately been found to exist in our country, and which spawns in March, and the California brook-trout which spawns in March and April.
The salmon come in from the sea where they have passed the cold weather, as soon as the ice breaks up, and keep on all summer long running up into the fresh water; which alone is adapted to the fructification of their eggs. Trout, in like manner, pass from the ponds and deep lakes into the cooler streams, where a constant supply of fresh and lively water can be obtained; whitefish appear from the depths of the great lakes and seeking the shallows along shore, select gravelly and rocky reefs and springy spots to lay their eggs.
Salmon and trout make nests, the female digging out the bottom and fanning away with her fins and tail the mud and finer sand from the gravel which she afterward uses to cover her eggs. When these operations are sufficiently advanced, she is joined by the male and they simultaneously, with one mutual impulse of amatory passion, deposit the eggs of the female and milt of the male. Only a certain number of these are extruded at a single impulse, and are then carefully covered over with gravel by the female, while the male divides his time between driving away intruders of his own sex, who would usurp his prerogatives and devouring such stray eggs as may have escaped the notice of his wife and been carried down stream by the current. One noticeable peculiarity of the spawn of this class of fish is, that the moment it falls from the parent, it adheres to whatever it touches. This is a provision of nature to enable the parent to cover it over with gravel before it is washed away, which she does with remarkable skill and care, moving the stones with her ventral fins and tail for that purpose. It remains fast for the space of thirty minutes or so, and then becomes loose and is swept away by the current, a dainty morsel for whatever bird or fish or insect that comes across it. It is also to be observed that the eggs are heavy and sink to the bottom like shot; a marked peculiarity of the spawn of the salmonidae, and distinguishing them from those of other varieties.
Several different deposits of spawn are made and covered up in this way, till often quite a mound of fish eggs and gravel is erected. Such mounds built by the famous trout of Rangeley and her sister lakes are large enough to fill a two-bushel basket. The operation of emitting the eggs is not all done at one time or on one day, it occupies several days. As soon as the nest is completed, and the father and mother are exhausted of spawn and milt, they drop back worn out and weakly to the deeper water or the ocean to recuperate. The eggs are left to themselves unprotected, except for their gravelly covering.
The enemies of fish life are numerous. The most to be dreaded are eels, which are difficult to exclude from the troughs, and devour eggs and young with equal voracity. Seven young trout have been taken from the stomach of an eel six inches long and no thicker than a fine knitting needle; they grow as they eat, hiding most cunningly in the sand or gravel from human eye, and making their way through narrow passages and small holes that a person would not suspect them of being able to enter. One half-grown eel will destroy an unlimited number of fry or eggs. Ducks are equally destructive, thrusting their long bills down into the nests of spawn, or seizing and swallowing the young; frogs, mice, rats, fish, many birds, and the larvæ of beetles and devil’s darning needles, and other water flies before they have developed into the perfect insects do their share of damage. A very large percentage fail to become impregnated, the current of water probably washing away the milt of the male before the sperms could enter the eggs. Mr. Livingston Stone says that in digging some spawn of the California salmon, deposited by the parents in the natural manner, in the McCloud River, he found only eight per cent. vitalized.
For almost thirty days after birth the salmon or trout eats nothing, but is sustained by the absorption of the stomach or what is more accurately termed the umbilical sac. All this while, as may be readily understood, he is awkward and hampered in his movements, an easy prey to any hungry enemy. Appreciating his position he strives to hide himself during this period; he crawls into holes and under stones, and often hides so effectually that when he has been artificially hatched his anxious foster father, the breeder, never discovers what has become of him, unless his breeding troughs are well made and free from worm holes. But in this, his hour of weakness, his enemies never desert him, they stand by him from first to last. At that stage of his development every miserable shiner, dace and minnow is his master, a very Giant Despair by comparison with his feebleness.
If he outlives all these perils and attains a marketable size, man steps in. Man takes the best and so upsets the equipoise of nature, which up to that time had by its checks and balances kept all varieties of living creatures at an established relative proportion. For every salmon he eats there are ten thousand fewer eggs for the water bugs and the minnows who will make up the loss out of those which are left. These embodiments of evil must be fed and grow more diligent in the search for food, the scarcer it becomes; still man keeps on with net, and spear, and hook, making yearly larger drafts as the human race increases and extending his machinery as the prey diminishes; so the whole system of nature is disarranged. The edible fishes at first diminish, then, as the process goes on in geometrical ratio they decrease more rapidly, and the operation becomes accelerated at every step, till the stream or lake which once abounded with excellent fish is utterly and absolutely denuded and left sterile, bare and unproductive. The insects have devoured the last edible fish which man’s greediness has failed to reach. This has happened with so many of the ponds and water courses of our country that it is safe to say, fully one-half of the lakes, rivers and streams throughout the older States, at least, yield nothing of food for man.