Centrarchus Æneus.—This is an entirely distinct species from the Black Bass, though, being somewhat similar in color and shape, is often confounded with them. The same may be said of the Oswego Bass, which is now ascertained to be equally distinct, though commonly known as bass, and supposed to be identical. The fish under consideration must in no wise be confounded with the Rock-fish of Pennsylvania, which is the Striped Bass, Labrax lineatus, and which the benighted Pennsylvanians would oblige us by calling by its right name.
The Rock Bass has two flat points at the angle of the gill-cover, and is distinguished from the variety last described by six or seven spines and eleven soft rays in the anal fin. The dorsal has eleven spines, and ten or twelve soft rays; the pectoral fourteen soft rays, the ventral one spine and five soft rays, and the gill-rays are six. The fin-rays are given by Dr. De Kay as follows:
D. 11.12; P. 14; V. 1.5; A. 6.11; C. 17-3/3.
This fish is found in much the same waters as the black bass, and, like the latter, made its way on the completion of the Champlain canal through it into the Hudson River. It takes any of the ordinary baits, preferring, however, the cray-fish, Astacus Bartoni, and can be
captured even with the fly, but not readily. In the St. Lawrence River it feeds mostly on the eel-fly, so long as that lasts, choosing, I believe, the dead ones; and in July I have found them filled with that fly. They never attain the size of the larger black bass, although they are taken of over three pounds, but are a brave, voracious fish, and excellent at table. [17]
Lucioperca Americana.—This fish is mentioned more on account of the absurd misnomers that have been applied to it, to warn persons against similar errors, than on account of its sporting qualities. There appears to be some confusion among naturalists concerning this family; there is probably an undescribed species. Dr. De Kay mentions a bluish fish which he regarded not as a distinct variety, but as an aged specimen. By a close comparison of the two, I am satisfied that although the scientific peculiarities are wonderfully alike, there are substantial differences.
The Pike Perch is called the Glass-eye, the Big-eyed Pike, the Pickerel, Pickering, and Pike of the Lakes; whereas a simple suggestion will establish the difference between it and the pikes or pickerel. The latter has all the fin-rays soft, and the ventrals in the centre of the abdomen, whereas this fish, which is a true perch, has many spinous rays, and the ventrals close beneath and just behind the pectorals.
The Pike Perch is of an olive color on the back, yellowish on the sides, and white beneath. It attains a weight of thirty pounds, and is distinguished particularly by the peculiarity of having the membrane attached to the last two rays of the first dorsal jet black, whereas that attached to the other rays is yellow. The lower edge of the gill-cover has been described as smooth, but I find the fore part of it slightly serrated; the posterior part has one flat spine, beyond which there is a pointed membrane, and above a rudimentary spine. There is a series of sharp teeth on both jaws and the gill-arches, two in the front of each jaw being long and conspicuous. The base of the tongue is roughened but toothless, and I can find no teeth on the vomer. The scales are not large, and have the edges marked out by a series of dots.
The fins, as I make them, are—
Br. 7; D. 13.2.20; P. 10; V. 1.5; A. 1.14; C. 17-3/3.
But according to Dr. De Kay they are—
Br. 7; D. 13.1.21; P. 15; V. 1.5; A. 1.14; C. 17-3/3.
The color of the anal is reddish yellow; of the ventrals light yellow, and pectorals yellowish olive. There are scales on the gill-covers; those on the fore gill-cover being scattered and few. Beyond these differences my examination found the ordinary pike of the lakes to accord with the description of Dr. De Kay; but the other species that I have mentioned was very different both in color and appearance, and is, as I conceive, the true Ohio salmon, a name that has been applied to the species just described.
As for the color in the latter species, that was totally different, being so far like the salmon as to have no doubt given origin to the name. It is bluish grey on the back, greyer on the sides, and white on the abdomen. The only part of membrane of the dorsal of the salmon that is black is that attached to the last spine alone of the first dorsal. The shape of the fore gill-cover is slightly different, and the spines on its edge are more distinct, and regular, like teeth. There are no bars on any fin except the dorsal; there are no scales on the gill-cover, and the fins are all light and transparent. There are minute teeth on the base of the tongue.
The fish that this description is taken from were found in New York market on the 25th day of February, and may have been altered by their winter dress; but they were unknown to the fish-dealers, one of whom called my attention to them and inquired their name. They did not weigh over a pound, and the largest was fifteen inches long, of which the head was four. Of the dorsal, the second, third and fourth rays were the longest. Being but a sportsman, I mention these matters to attract the attention of the learned, who would do us a favor if they would seek out the old Indian names to apply to our anonymous fish.
There is a third described species of lucioperca or pike perch, as the word means; lucioperca grisea, that is found in the limits of New York, as well as the lucioperca canadensis, which belongs to Canada.
It is to be observed that Dr. De Kay puts the length of the lucioperca americana at 14.5, but says they are occasionally much larger; whereas the fish known as the pike of the lakes is taken in immense quantities in Lake Ontario, in April, of twenty pounds’ weight, and rarely falls below five. There is a small pike perch known as the sorga, with the same general characteristics, but with the membrane attached to the last spine-ray of the first dorsal alone black. The back is yellow mottled with black, and shaded down the sides to white on the abdomen; the first dorsal is yellow with dusky spots; the second dorsal and tail yellow with dusky bars; the gill-cover is scaled and the fore gill-cover partly scaled. It is precisely the shape of what I call the Ohio salmon but of a totally different color. Its length is about twelve inches, and its weight does not exceed a pound. The fin-rays are—
Br. 7; D. 12.1.18; P. 12; V. 5; A. 1.11; C. 17-6/6.
There are unquestionably at least three distinct varieties, besides the grey and the Canadian pike perch; they are popularly known as the pike the sorga, and the Ohio salmon, and all are highly esteemed for the table.
Perca Flavescens.—The Yellow Perch has, as his name indicates, a predominant yellow color on his sides; there are a number of dark vertical bars over the back, and the pectorals, ventrals and anal are orange. The gill-cover is serrated beneath and armed with a long spine, and the fore gill-cover has a toothed margin. There are two dorsals; the ventrals are beneath and slightly behind the pectorals, and the teeth are minute. The greatest weight is four or five pounds. The fin-rays are as follows—
D. 13.2.15; V. 1.5; A. 2.8; C. 17-5/5.
Unfortunately, this fish, equally despised by the gourmand and the sportsman, abounds in our fine ponds and lakes, that ought to be devoted to his noble congener, the black bass. He will take the fly if it is allowed to rest in the water, and after hooking a trout that had fouled in the weeds, I have found a perch on the second fly. He spawns in April or May, seeking the sandy shore, near projecting roots, where there is a depth of a foot of water. I have seen them crowded together, male and female, jostling and following one another round and round through the roots, pressing out milt and spawn, and so busily engaged that they could be taken with the net or the hand. In mere wantonness and desire to diminish their numbers I destroyed all I could, hanging them on strings with the spawn streaming from them. The eggs, which were almost transparent, were in the water in masses, kept together by a glutinous substance, and each marked with a black spot, and could be taken up in the net, straining slowly through the meshes.
Yellow perch will take worm or minnow, preferring the former, and it is probable destroy numbers of young trout. Their flesh is coarse, white and tasteless. They are pursued only by boys and ladies.
There is no subject more important to the material welfare of our country, or that a persistent and willful disregard of the laws of nature has rendered more necessary, than the culture of the various tribes of fish that were once abundant in our rivers and lakes and along our coasts, but which are rapidly diminishing, and threaten soon to become extinct.
Fortunately great strides have been made and great interest aroused in this matter, and the only article in the first edition of this work which the author has felt himself called upon to seriously modify, is that upon this subject. Then there was not a Fishery Commission in a single State of the Union, nor was there a skilled fish culturist in the land, except perhaps Dr. Garlick, who was making experiments out West, and Mr. Seth Green, who was studying out the spawning habits of fish by himself, by the side of the forest streams, and laying in stores of knowledge which were to serve as a foundation for the great fish-cultural fame that he has since acquired. The author may claim that his former few pages of advice and instruction may have tended in a measure to bring about the change, and to give to us State Fishery Commissions in a great majority of the States, and a National Commission that has no equal for scientific attainments or practical work in the world. For the creation of the latter, the author also claims not merely the influence of his writings, but his assistance as a member of Congress in getting the law passed which established the United States Fishery Commission, and placed it under the charge of so efficient a public officer as Mr. Spencer F. Baird.
At that time there was hardly a word written on the subject in this country except a pamphlet by Dr. Garlick, and such translations from the French as described the operations under Prof. Coste, and accounts of a few limited English experiments. Not a private establishment for the cultivation and sale of fish on any considerable scale existed, and no expectation that any large public benefits would ever arise from fish propagation, was generally felt. Since that time hundreds of books have been written in this country alone, the time of scientific men has been devoted to it, fish cultural societies have been formed, and there are several successful establishments for the hatching and sale of young fish. In no development of this wonderful country has there been so remarkable an advance, such a change from darkness to light, such an elevation of public opinion, as in this matter of the artificial increase of fish.
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.
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.
The trout will not spawn in the ponds where the bottom consists of large stones or weeds; but if there is sand or gravel anywhere on the bottom of the ponds, they will spawn on it. Therefore be careful to have only the raceway, where the water enters, covered with gravel. In October this may be washed and cleaned from the weeds which will have grown in it during the year. As soon as the fish are ready to spawn, they will ascend from the ponds into the raceway, seeking a place to nest. Then they are ready to be taken out and the spawn expressed. At the entrance of the raceway, there should be grooves to receive a frame, on which is tacked a net of coarse bagging about eight or ten feet long. One corner of this bag should be narrowed, left unsewn, and tied with a string, like the mouth of a meal sack. The race should be covered over in spawning time, as the fish will come under the cover better and are not so likely to be frightened by any one passing. If there are fifteen hundred or two thousand fish in the pond, the net may be used every day in the height of the season, and when the fish become scarce, once in two or three days.
Indications of spawning having been observed, the covers are put on the races, and as soon as there are fish in the raceway, the net is gathered up in one hand and the frame held in the other, in such a position as to be put in the grooves as quickly as possible, so as to let none of the fish escape from the race. Go quietly to the spot, and do not walk down the raceway to get to it, but approach from one side and put the net in the grooves as quickly as you can. The water running down will swell the net out to its full length. The covers may be then removed, and with a stick you may frighten the fish down from the head of the raceway into the net. As soon as they are all in, the frame may be lifted out of the water, and the fish are then enclosed in the bag. A tub of water should be previously brought near the spot, and the end of the net can be lifted into the tub and untied, when the fish will all fall into the tub without trouble. Coarse cloth is better for the purpose than netting, as it can be more easily tacked to the frame, does not hurt the fish so much, and lasts longer; besides, the water swells it out and holds it open for the fish to run in better than it would a net, and the fish not seeing you through the cloth as they would through an open mesh, are not scared, and do not try to run back up the race.
The fish being now in the tub, must be taken to the hatching house without any delay. There are probably in the tub some fifteen or twenty fish, and all the operations must be conducted as quickly as possible, so that they will not die in the small quantity of water to which they are confined. So long as the fish lie quiet in the bottom of the tub, there is sufficient air in the water to sustain them, but as soon as they come to the surface and try to leap out, it is a sign that the air is nearly exhausted and the water should be renewed. They will also open their mouths wide, just as a person would when gasping for air. Trout will die in a tub out of which the oxygen has been exhausted by their breathing, more quickly than they would die in a cloudy day if out of the water entirely.
A fire may be made in the hatching-house to warm your fingers, which will probably get cool while engaged in this operation. A six-quart milk-pan is to be provided, if you have many fish, and also another tub of water, into which to put the fish after they are deprived of their spawn. Select a fish, and holding it over the milk-pan, which has been dipped in water to wet it, rub it gently with the fore-finger and thumb, from the pectoral fins to the vent. A little experience will show how this is to be done. If the fish is ripe, a few drops of pearly-colored milt, or orange-hued eggs, will be forcibly expressed in the pan. If the milt is not of this color, it shows that the milt is not good, and another male must be taken, and treated in a similar manner. The female must be pressed more slowly and oftener than the male. If the eggs are not ripe, by passing the hand lightly over the belly, you will feel them beneath, hard, like shot. In that case put the fish back into the pond, for the eggs to ripen. When the eggs are ripe, the belly will be soft and flabby, and the eggs beneath the skin feel loose and change their position at the touch. The operation must be continued until the fish are emptied of eggs and milt. The eggs in the pan may, at intervals, be gently stirred by moving the pan; this is to change the position of the eggs, so as to be sure that all come in contact with the milt, and when the operation is completed, a half-pint of water is poured on them and the pan set in one of the hatching troughs through which the water is running; this will keep the eggs up to the proper temperature, and prevent a sudden change when they are transferred to the trough. The eggs will now agglutinate or stick to the pan, and to each other, for a little while.
The fish must be grasped by the head, if you are right-handed, with the right hand, and by the tail, or rather the lower part of the body, with the other hand, and held over the pan with the belly near the bottom of the pan. As soon as the fish is quiet, the right hand may be gently slipped down from the head, and the fore-finger and thumb used to press the belly. The fish still being held by the tail, and lower part in the left hand, and partly supported, perhaps, by the sleeve of the coat, or by the bare arm, and the remaining fingers of the right hand. The pan should be elevated at one side, during the operation of taking the spawn, by standing it on a block half an inch thick, and enough water will drip from the fish so that by tilting and shaking it, the milt can be brought in contact with the eggs.
After stripping a female once she should be returned to the tub from which she was taken, and should be stripped again after a short time, during which other fish are being handled. This is to get the last egg from her, and if it is not done a few will remain and she will go on the spawning beds to deposit them as if she had a full supply. If she is cleaned entirely, she will not bother herself or her owner about the matter again that season. The California mountain trout retain their eggs and milt with more determination than our brook-trout, and must be humored like a cow that will not give down her milk to any one but the creature for which nature intended it. After the trout are handled they are returned to different tubs, according to their sizes, as this is the occasion to sort them.
Twenty to twenty-five minutes having now elapsed since the pan of eggs was set in the trough, gently tip up the pan. If the eggs are loose and roll separately as you move it, they are ready for subsequent operations; if not yet loose, let them remain a while longer. Pour off the dirty water until only sufficient is left to cover the eggs. If this is done very gently, the eggs, although very light, will remain at the bottom, as they are somewhat heavier than water; then sink the pan into the water, at the same time tipping it, and take it half full of water. The influx of water will wash the eggs around somewhat, and dilute the dirty water remaining in the pan. This is to be poured off, as before, and the operation repeated, until the water looks perfectly clear. There will be some dirt and droppings of the trout still left, which can be carefully picked out with the nippers. If an egg should happen to be broken, while being taken from the trout, every vestige of it should be carefully removed, as the slimy, sticky contents will get on the other eggs and kill them. The eggs are now ready to be placed in the trough, as soon as you shall have raised the water in the nest to which you wish to transfer them, by placing a strip across the trough. Then sink the pan gently to the edge in the water of the trough, at the same time tipping the pan, so that the water in the trough and in the pan shall come together with as little current as possible. Then the edge of the pan may be sunk into the water, and by tipping the pan a little more, the eggs will flow out without injury. By moving the pan while the eggs are running out, they may be spread uniformly over the bottom. If they fall in a heap, take the bearded end of a feather, and move the water with it in the direction you wish the eggs to go, and they will follow the current thus created. This may be done without touching the eggs with the feather. Distribute the eggs as evenly as possible over the surface of the nest. Where they are placed upon wire sieves, these may be moved and shaken under water, so as to distribute the eggs evenly.
The strip which was placed across the trough to raise the water, should then be removed. Care must be taken that it be not removed so suddenly as to cause a rush of water, which would carry most of the eggs away with it. Raise the strip a little way from the bottom, so as to let the water run out gradually, and when it is very nearly or altogether at the proper level, the strip may be removed entirely. Those who have a nursery attached to the troughs, place the earliest eggs in the lower end of the trough, and keep placing them toward the top, so that the fish which are first hatched can run first into the nursery without disturbing the others. About ten thousand may be placed in each nest eighteen inches by fifteen inches.
If the eggs have been received from a trout breeder, they should be left in the packages in which they have been sent until the troughs are ready for them. Persons will sometimes take the tin boxes containing the eggs out of the sawdust in which they were packed, and set them in the water of their troughs, with the idea perhaps of getting the eggs in the box to the same temperature as the water before unpacking them. This will surely kill the eggs in a few hours. Leave them in the original package until a few hours before you are ready to place them in the troughs. Then take out the tins and set them over or near the troughs, which will reduce or raise the temperature enough. Then empty the box into a tin pan full of water taken from the trough, pick out as much moss as you can readily with your fingers or nippers, and wash off the rest in the manner shown in directions for washing eggs hereafter.
The eggs are placed on trays made of wire cloth stretched on wooden frames. Each tray is twenty-seven inches long by fourteen inches wide, and will hold in a layer, one deep, six thousand two hundred and seventy-two salmon trout eggs. Instead of using only one layer of these trays, it has been the practice of late years to use four layers in the upper sections and five in the lower sections.
If only a few eggs are to be hatched (say eight or ten thousand) no hatching house is necessary. The troughs may be placed in the open air, in any convenient place, and covered with a wire screen, to keep out rats, mice and ducks. A light board cover must then be laid over them, to shed the rain and snow and keep the eggs from exposure to the sunlight. A hatching house is much more comfortable to work in. A stove may be put in it and a fire started occasionally for warming one’s fingers, but it is not needed for hatching purposes, as spring water in these latitudes is warm enough. The house may be constructed of rough boards, or as expensively as you choose, but care should be taken to have a water-tight roof, as drops of water leaking through and falling into the troughs will kill the eggs underneath. Its size must be regulated by the number and extent of the troughs.
The windows in a hatching house should be few in number and provided with curtains or shutters, as the sun shining upon the spawn will kill it. Not that a few minutes’ exposure to the rays of the sun will hurt the eggs, but a few hours’ exposure certainly will. Perhaps it would be well to have the windows, if possible, made on the north side of the hatching house, into which the sun will not shine in the winter season. Keep the hatching house clean. In fact cleanliness is one of the cardinal virtues to the trout raiser. He should have a clean house, should work with clean hands, and have all his pans, spoons and utensils of every sort free from grease and dirt.
The troughs should be made of seasoned timber, one and a half inch thick. They should be six inches deep and about fifteen inches wide, inside measurement. It would be better, perhaps, if the troughs were eight or nine inches deep, because then the water could be raised higher over the young trout after they are hatched out. The difficulty in making them so deep is that when the sides of the trough are made so wide, they are apt to warp or stretch apart at the top, and must be stayed in some way; for instance, by strips nailed across. But the cleaner the trough is of all strips, elbows, or grooves, the better. The troughs are divided into squares or nests by cross strips set on the bottom at intervals of eighteen inches. These strips may be made of half-inch stuff and cut two inches in width. There is no necessity for nailing them to the bottom; fit them in accurately and set them edgeways at intervals of eighteen inches. As they do not need to be removed often, it is better to make them fit tightly. Other strips of the same stuff must be provided, to fit upon these and made wide enough to raise the water within an inch of the top of the trough; as these need to be often moved, they must be made loose enough to take out, and yet fit accurately enough to raise the water over them when they are put in. New wood under the action of water develops a slimy sap, therefore it is necessary to paint the troughs with hot coal tar mixed with enough turpentine to thin it to about the consistency of paint. The troughs should have an inclination of about one inch in eight feet—just enough to let the water ripple gently over the cross strips. They should not be longer than twenty feet, or the air in the water will be exhausted before the water reaches the end of the trough. There is more danger of this after the eggs are hatched out and the troughs are full of young fish. If possible, the hatching house should be so far below the level of the spring from which its supply of water is derived, as to allow the troughs to be raised two or three feet from the floor.
The filter is a box six feet long by one and a half feet wide and one and one-half feet deep; in which four or five flannel screens can be placed through which to filter the water before it passes into the troughs. The coarsest and cheapest red flannel is the best. It will rot and must be renewed once or twice in a season. Red flannel will last twice as long as any other. The flannel should be tacked on frames running in grooves set at an angle of forty-five degrees (the top down stream), so as to expose as much surface as possible to the water.
Sediment falling on the egg keeps the water off and destroys its life as effectually as if buried in the mud. If sediment falls upon the eggs it may be removed by gently agitating the eggs with a feather, or better still, by creating a current in the water with a feather.
From the filter the water runs into the distributing trough or pipe, which runs along the head of all the hatching troughs. The water may be let into the hatching troughs by faucets, or through holes cut into the trough. These holes should be covered with netting, or the young fish will run up out of the troughs into the filter, or coarse gravel may be heaped up at the head of the trough through which the water will run, but through which the young fish cannot work their way. The supply of water for one trough should be equal to that coming through a three-fourth-inch hole with three inches head; just enough to make a gentle ripple over the cross-pieces. Be careful to get the troughs level crossways, and the strips true, so that when the water is running it will form an equal current over every part of each strip along the whole length of the trough. The length of time required to hatch out the eggs depends upon the temperature of the water. A general rule sufficiently accurate for all practical purposes is this: At fifty degrees trout eggs will hatch out in fifty days, each degree colder takes five days longer, and each degree warmer five days less. The difference, however, increasing as the temperature falls, and diminishing as it rises. The best temperature for hatching is between thirty-five and forty-five degrees.
After the eggs have lain in the water from fifty to seventy-five days, according to the temperature, the trout will begin to make their appearance, the egg appears to be endowed with life, and the motions of the trout inside “kicking” against the shell to force a way out can be plainly perceived without the use of a microscope. At length the trout forces his way through, head first or tail first, those that hatch head first always dying, however, and the useless shell floats away down stream. The trout is then about one-half inch long, and the body proper as thin as a needle; the most prominent features being a pair of eyes, huge in comparison with the rest of the body, and a sac nearly as large as the egg. This sac is attached to the belly of the fish, and contains food, which the fish gradually absorbs. If the fish are hatched in fifty days, the sac lasts about thirty, if in seventy days, about forty-five. At this period of their lives they will work down into the crevices of the gravel and along the sides of the troughs and stay there, nature seeming to give them the instinct at this weak and defenceless period of their lives, when they are burdened with a load which they can hardly carry, to get out of sight and out of the way of harm.
The most critical period in the life of a trout commences when the umbilical sac is absorbed. More, perhaps, die from the time they begin to feed until they are six months old, than at any other time. In consequence many different plans for nurseries have been suggested and used. The fry require a largely increased supply of water, but where only a moderate number is to be raised, in place of erecting other and wider troughs or boxes for nurseries, the better plan is to put only a few eggs, say five hundred, into each square or nest of the hatching trough. The square is then large enough with the water raised to keep the trout well for a month or two after they commence feeding, when they may be transferred into the first or upper pond.
The fry are removed from the troughs into the pond by the use of a small net. Take them upon this, a few at a time, and put them into a pan of water; they will swim off the net and you may draw it from under them. In the pan they may be carried, a thousand at a time, to the pond in which you wish to place them. Put them into still water; they will settle down on the bottom and remain there for some hours, then they will begin to explore their new quarters, and in a few days will become thoroughly habituated to the place.
The best food for trout fry is raw liver, chopped as fine as possible, and then rubbed through a screen or sieve with a flat stick. It must be reduced to the consistency of pulp, and contain no strings or gristle. A chopping machine is made for chopping hash or sausage, and either that, or a couple of sharp knives are used to chop the liver. What is used is mixed with water so as to reduce it to about the thickness of cream. A teacupful of this mixture will feed a hundred thousand fish when they first begin to feed. The best way to feed them is to take a case-knife, dip it in the food and “slirt” off what adheres into the troughs; a very simple way, but one answering all practical purposes. Care should be taken not to feed too much, else the surplus food will remain on the bottom, and decaying there foul the trough. The reason of the difficulty in raising young fish appears to be that they are literally starved to death. The food which we can give them is not natural to them, it is often given in such coarse pieces that they cannot take it, and sometimes, through the carelessness of a hired hand, they are neglected two or three days at a time.
Young salmon, young salmon trout, California mountain trout, and above all young California salmon are larger, have stronger appetites, and will accept coarser food. For them, although at first the liver should be made as fine as for trout, when they are a few weeks old it will be hardly necessary to dilute it at all, and in the course of a few months they will not only take the larger pieces, often tearing them apart, but will scorn the finer portion. At one time sour milk was almost exclusively used for feeding young fish, but it has been given up. Other foods have been tried, but with no better success. The fish will not thrive on any of them as well as they do on liver, and do not thrive on that as well as if it were a natural food. Near the salt water, where soft clams can be obtained, they are used in place of liver.
As they grow older, other things may be substituted or may be added to it as a change. They are fond of the roe of other fish, of the spawn of the horse-foot or king-crab; of fish itself, and when they are large enough to eat minnows, no better food can be given them. Liver is too expensive when it has to be used alone for grown fish, and beef lights are usually added to it or used in place of it in a measure. It is miserable food, however, much of it passing through the stomachs of the trout and salmon wholly undigested and collecting in the bottom of the ponds. It injures the digestive organs and must be deleterious to the health of the fish. Its only recommendation is that it is cheap. Maggots are bred on spoilt meat, hung over the ponds, and as they fall off and drop into the water are readily devoured, and make excellent food. Or a piece of spoilt meat may be placed in a deep bottle like a preserving bottle, and the flies that will collect in immense numbers during summer may be caught and emptied into the water. This trap will take many times its bulk of flies being kept set all the time and emptied when any one is passing it. Flies are probably the best food that can be given to trout.
Shad eggs differ essentially from trout eggs and require wholly different manipulation. They are much smaller and lighter. If a trout or salmon egg is dropped into water it sinks at once to the bottom, but a shad egg will almost float, and has but little more specific gravity that the water itself. Shad eggs are less than half the size of trout eggs, and require as their best condition for hatching a temperature of from sixty-five to seventy-five degrees. They will hatch at a lower temperature, but in such cases mature slowly, while eighty degrees of heat is as much as they can endure. When experiments were first made in their artificial propagation, they were placed in ordinary trout troughs, and much trouble was found in their management. If a current of water was turned on to the same extent as with trout, they all washed over the end of the troughs, while if the supply was diminished so that they retained their places, they died of suffocation. It was only after many different devices had been tried that the proper invention was discovered—a simple box with the bottom knocked out and replaced by a wire gauze netting. This box is suspended by floats of wood nailed on the sides, so that the bottom is presented at an angle to the current, the degree of inclination being determined by the velocity of the current. The water striking against the screen enters the minute interstices, and lifting the eggs, keeps them in gentle motion like the bubbles of air in a pot of moderately boiling water. All that is necessary is to attach these boxes one behind the other in a long row, anchor them in the river, and fill them with impregnated spawn, and the work is done. The continuous motion of the water passing around each egg and holding it suspended, aerates it perfectly and makes its hatching a certainty. Hardly one per cent. of healthy eggs fail to hatch, and while the process is going on hardly any care or attention is required. Fish and eels cannot enter the boxes to prey, nor can the eggs be driven out by the water, and lost.
In the artificial manipulation of shad the parents are taken in seines from their spawning beds. The haul is made at night, at which time only can ripe fish be found in any considerable number. The captured fish are thrown indiscriminately into a boat and are stripped at once as they die quickly. They are afterwards sold in the markets. The eggs, which are caught in a pan with a little water in it, after being allowed to stand for a few minutes until impregnation is complete, which is signified by their swelling in size and reducing the temperature of the water some ten degrees, are poured into the hatching boxes and left to themselves. Nothing more is required. In twenty-four hours the black eyes of the young fry will be visible through the shell, and in from three to ten days they will be hatched.
Black bass is one of the most prolific varieties of our fresh-water fish. Their natural increase is so great and their growth so rapid, that it has never been an object to fish culturists to attempt their artificial propagation. When the spawning season draws near, they select, guided by natural instinct, with great care for the purpose of propagation, certain portions of the river having a pebbly or gravelly bottom. From these they remove carefully all sediment, weeds, and sticks. This work completed, leaves a clear bright space in the bottom of the river, circular in form, and having a diameter of about three feet. These beds are readily distinguished by the casual observer from the ordinary bottom of the river by their brightness, the gravel having the appearance of being washed or scoured. When the parent fish are ready to spawn, the female goes upon this prepared bed and deposits her spawn in a glutinous band or ribbon, running in various directions across the bed. She is followed by the male who impregnates the eggs by the expression of his milt.
Their care of the young (the exercise of which is peculiar to the bass, sunfish, and catfish), taken in connection with the fact that a large pair of bass will deposit twenty thousand eggs, will give some idea of their fertility. Possibly the fish are capable of reproduction when two years old, having at that time attained the extraordinary length of eight or nine inches, but this is mere conjecture, based more particularly upon our knowledge of the size and weight of the fish at that age. They frequently attain the weight of five and six pounds; in rare instances seven and eight. They are unsurpassed in flavor by any of the perch family.
The black bass loves bright, pure, lively water, not as cold as the trout streams of our spring-producing hills and mountains, but free from foul matters held suspended in it, and with motion either of current or from the winds. It deposits its eggs on rocky or pebbly ledges. The parents guard and protect their nests till the young are hatched, and even watch over the latter till they can take care of themselves. The fish generally selected for transfer are from one to three years old, measuring from three to twelve inches in length. Fish of this size are not only more numerous, but they bear transportation better, and are more readily acclimated than when larger. They are moved with a great deal of difficulty in hot weather, especially when the journey requires more than twelve or fifteen hours; but with care and skill no serious loss need take place.
The implements of the fish-culturist are few and simple. A few feathers may be kept on hand to use in spreading the eggs when placing them in the troughs, in collecting them for packing, and moving them in the search after dead eggs. Nippers made of wire or some elastic wood, like red cedar, bent or cut into the shape of the letter U, elongated to about six inches, and with loops of wire at the ends about the eighth of an inch wide, will hold an egg without trouble. A small homœopathic phial is used to examine the eggs. The manner of its use is, to fill it with water, put in the eggs to be examined, cork it, hold it up before the window in a horizontal position, and with your microscope look up through the side of the phial. This brings the egg which lies at the bottom of the glass within the focus of the microscope, and the water does not distort its shape. The microscope need not be very strong; one magnifying eight or ten diameters is amply sufficient. A small net will be of use in removing the young fish and any refuse in the water from the troughs; it should be about six inches in diameter, in the shape of the letter D, with the handle on the middle of the bend. It is very easily made by bending a wire in the desired shape, and twisting the two ends together for a handle. Thin gauze of some kind, like bobinet, should be spread over the wire so tightly that the middle of the net shall hang only a half inch below the level. An iron spoon, well tinned or silvered, is used to remove the eggs. Some six-quart tin milk-pans will be necessary, for a variety of purposes. Eggs may be counted most easily by measuring them. For this purpose take any small glass, such as a very small tumbler, for instance, count out five hundred or a thousand eggs, and with a file make a mark upon the glass as high as they reach, and the measure is always ready to your hand.
A watering pot with a fine rose spout is used to wash sediment from the eggs on the sieves, and a broom of twigs is used to brush the screens of wire.
One of the most curious and interesting results of fish-culture has been the production of hybrids, some of which were reproductive and have thus created new species. Strange as it may seem, these experiments have rarely been wholly abortive; no matter how dissimilar the families, the eggs have been impregnated often to a large percentage, and have hatched. The following varieties have been crossed:
| FEMALE. | MALE. | ||
| Salmon-trout | with | White-fish. | |
| “ “ | “ | Brook-trout. | |
| Brook-trout | “ | Fresh-water Herring. | |
| “ “ | “ | California Salmon. | |
| “ “ | “ | “ Mountain-trout. | |
| Shad | “ | Striped Bass. | |
| “ | “ | Herring. | |
It is observable of all hybrids that they are shy and wild; more so usually than either of their parents, and that in appearance they favor their larger parent. The cross between the brook-trout and lake-trout has been repeated from year to year, till fish which are one-eighth salmon-trout and seven-eighths brook-trout have been produced which it is hoped will have the size and toughness of the mother, with the beauty and gameness of the father.
These experiments commenced with a cross of the brook-trout and California salmon, which had an interesting and instructive termination, and prepared the way by its failure for subsequent successes.
In September, 1879, the young of the brook-trout and California salmon were seen to be maturing their eggs. This was the first time in the history of fish culture that hybrids gave evidence of breeding. It is asserted that among animals, mules are occasionally known to produce young, but this is a most unusual exception to a general rule. No more was expected from the experiments in crossing varieties than the production of combinations which might be valuable in themselves, like the capons among fowls, or the mules among draught animals, but which must of necessity be purely ephemeral, and perishing with the lives of the individuals. But when these hybrid trout-salmon were opened and found to contain eggs quite large and well forward in maturity, it seemed possible that new species might be created and made permanent. The eggs were already larger than the mature eggs of the trout, although it was then early in the season, and seemed perfectly healthy. As time passed the parents were watched with care, and were soon seen to be going into the spawning-race. They apparently made all their preparations for spawning, began digging their nests, stayed about them, and proceeded in the regular way, except that they were never in pairs, but always single. This was not natural, and led to a careful examination of them individually. After examining some fifty out of the sixty, the conclusion was reached that they were all females, which eventually turned out to be the case. This was in the latter part of November, 1879. Some dozen male brook-trout were then placed among the hybrids, to see if they would induce the latter to spawn. Everything soon appeared favorable for this result, the trout paired with the trout-salmon, they entered the race-way together, and occupied themselves with parental duties, but no results were perceived. For some reason the spawn was not deposited. Then some of the fish were selected to be stripped by hand, and were found to be ripe, but the eggs were all crushed in passing from them. The vent of the ovaries or ovaduct was too small to allow the eggs, which had delicate shells, to pass. Attempts were then made to enlarge the vent, and some thousands of eggs were finally obtained in this way uninjured. To impregnate these the milt of the male trout was used. The parent fish were left in their pond and seemed to be uneasy. They were doubtless incommoded by the eggs which they could not pass, and moved about slowly with their heads towards the bottom, their tails upward, and their bodies at an angle to the surface. The eggs which it was hoped might be impregnated by hand, were retained until January 25, 1880, when it was found they were unimpregnated and dead, and they were thrown away.
Thus two extraordinary facts were ascertained, one that the eggs may be too large for extrusion in case the male parent is the larger variety of fish, and the other that the entire body of one hatching may be of a single sex as in this case when all were females, and in the case of the shad and herring in the Hudson River, which are all said to be males. It was on these two discoveries that subsequent improvements were founded. It is not yet positively determined that these cross-breeds will procreate their species in a natural way, nor even that they will be the improvement, which has been hoped, but that they can be bred artificially there is no further doubt.
An indirect result of fish-culture has been the introduction of foreign fish into home waters. The German carp has been brought to America, and has increased and multiplied vastly, and been found well adapted to certain waters, which are not valuable for finer fish. In dull, muddy, small ponds, they have not only lived, but they have grown to a remarkable size. We have also received some German trout, which hatched and grew well, and which promise finely for the future. Then we have sent our black-bass to Europe as well as our trout, the California trout and salmon. We have acclimated in California the Eastern shad, and imported from California the trout and salmon of that country. This interchange has been mutually advantageous and promises to be much more so in the future. The results of fish-culture have indeed far exceeded the most sanguine hopes of those who first took it up, and at present there seem to be no limits to its beneficial effects. The time will surely come when the streams, which have been so long utterly depopulated of their natural inhabitants will once more be restocked and yield as abundantly as ever. This has already happened with the Connecticut River, which from having been almost exhausted, has been so successfully restocked that it produced in one year more shad than had ever been caught from it since records had been kept. The Hudson River had been also rendered nearly worthless as a shad river when fish-culture was first applied to it, the nets were being taken up and the fisheries abandoned, the price of even small shad had risen so as to exclude them from all but the tables of the rich, whereas now the yield is nearly as numerous as ever, and much larger fish are taken. So while neglected Southern rivers are exhausted, the Northern ones are being replenished. The same will follow with the fresh waters. If the trout brooks have become too warm from the destruction of the forests, other varieties, such perhaps as the California trout will be substituted. There are millions of just such streams and ponds, which are now nearly valueless, but which could be made quite as valuable as the same amount of land. These will yet all be replenished till the streams and ponds will come to be regarded as the most valuable part of the farm or country place, and millions of property will be added to the wealth of the country.[18]