LI BRA.RY UNIVERSITY OF CALIFORNIA. OIKT OF* /Kl/r6. ^CT^vx/ 4 Received QCT 29 1892 , / OF THB ^f f TT If T W W T* ft v »• _) Entered according to Act of Congress, in the year 1872, BY LIVINGSTON STONE, the Office of the Librarian of Congress, at Washington. UNIVERSITY PRESS: WELCH, BIGELOW, & Co., CAMBRIDGE. TO THEODORE LYMAN, THE LEADING SPIRIT IN THE NEW FISH RESTORATION MOVEMENT IN NEW ENGLAND, THIS BOOK IS RESPECTFULLY DEDICATED BY THE AUTHOR. PREFACE. To warn my successors of the dangers into which I fell myself as a pioneer, and to make their path easier, is the object of this little book. CONTENTS. PART I. TROUT-BREEDING WORKS. CHAPTER I. INTRODUCTION. Page Trout can be raised successfully. — Qualities required for the Best Success.— The Principle of Security, — em- phasized because, I. It will insure Success ; 2. Losses occur on so large a Scale ; 3. Sources of Danger un- seen. — Suitable Water, Importance of. Precautions : i. Be ware of Insufficient Water; 2. Of Freshets; 3. Of Water that heats in Summer ; 4. Of Water intrinsically Unfavorable to Trout. — Spring and Brook Water com- pared 3-17 CHAPTER II. PONDS. A Beginner's Inquiries. — Directions about the Construc- tion of Ponds : i. Exercise Forethought in locating Ponds ; 2. Excavate the Ponds rather than dam up the Stream ; 3. Build compactly ; 4. Build small Ponds for Business ; 5. Have a Fall at the Head of each Pond ; 6. Do not build Ponds too near the Spring ; 7. Build Keeper's House very near the Ponds ; 8. Make Ponds X CONTENTS. very Secure ; 9. Shape of the Ponds ; 10. Be able to draw off the Water; n. Beware of Hiding- Places ; 12. Number of Ponds; 13. Protections for Ponds; 14. Spawning Beds. — Ainsworth's Spawning Races. — Collins's Roller Spawning Box; 15. Inlets and Out- lets; 16 Screens 18-39 CHAPTER III. BUILDINGS. Buildings required. — Meat Room. — Store-Room and Car- penter's Shop. — Office. — Ice-House. — Other Struc- tures. — Hatching House. — Size of Hatching House ; Location ; Shape ; No Fire required ; Skylights ; Wa- terproof Partitions 40-46 CHAPTER IV. HATCHING APPARATUS. Enumeration of Hatching Apparatus : I. Supply Reser- voir; 2. Hatching- Room Aqueduct, Effect of Air on Temperature of Water ; 3. Filtering Arrangements : Nature of Sediment, Filtering Tanks and Screens, Flannel for Filters, Cleaning the Filters ; 4. The Dis- tributing Spout, Temporary Aqueduct, Gravel Filter ; 5. Hatching Compartments or Hatching Apparatus proper, Responsibility of. — Materials. — Glass Grilles vs. Charcoal Troughs. — Expense of Carbonized Wood compared with Glass Grilles. — Discovery of Carbonized Wood for Hatching. — Wood lined with Glass inade- quate. — Placing the Hatching Troughs ; Dimensions ; Compartments ; Elevation ; Inclination. — Screens. — Trap-Box. — Laying the Gravel ; Size of Gravel ; Prep- aration of; Depth. — The Covers. — Most Embryos develop' in the Dark. — Covers a Protection from Ene- mies. — Glass Grilles. — Wire-Netting Hatching Trays. — Various Methods of using Trays : I. The One-Tier Method; 2. The Double-Tier System; 3. Williamson's CONTENTS. XI Method ; 4. Clark's Method ; 5. Helton's Method ; 6. The. Use of deep Trays with the Williamson Hatch- ing Troughs 47 - 79 CHAPTER V. THE NURSERY. Introduction. — The Water. — Methods of Rearing. — Ponds vs. Rearing-Boxes. — Rearing-Boxes ; Essential Points of: I. A Fall of Water ; 2. A Current; 3. Pro- tection against Suction; 4. Security from Overflow; 5. Absence of fixed Hiding- Places ; 6. Compactness ; 7. Protection against Outside Enemies; 8. Perfectly Tight Joints; 9. Protection against Fungus. — Maxi- mum and Minimum Supply of Water. — Arrangement of Rearing-Boxes. — Directions for Ponds . .80-90 PART II. PROCESSES IN TROUT BREEDING. CHAPTER I. TAKING THE EGGS. Introduction. — Preparations for the Spawning Season. — The Spawning Season. — Appearance of the Two Sexes. — The First Fish up. — Method of Capturing. — Hold- ing the Fish.-— The Writer's Method. — Directions about Handling. — Impregnating the Eggs. — Russian Method. — Russian vs. American Theory. — How to tell Ripe Fish. — Further Directions for Impregnating the Eggs : i. Use Eggs that flow easily, and no others ; 2. Use good Milt and plenty of it ; 3. Make Quick Work in Impregnating the Eggs ; 4. Allow the Eggs Ample Time to separate ; 5. Rinse thoroughly ; 6. Practise to acquire Dexterity. — Closing Notes. — Time of Spawn- ing.— Age. — Number of Eggs. — Effect of the Weather. Xll CONTENTS. — Best Days for Spawning. — Spawning in the Pond. — The Spawning Pans. — Placing the Spawn . 93-123 CHAPTER II. HATCHING THE EGGS. Kind of Labor required. — Dangers : I. Fungus ; 2. Sedi- ment ; 3. Living Enemies ; 4. Byssus. — Examination of the Eggs. — Instruments for Picking out Eggs. — How to tell Dead Eggs. — Method of Procedure. — Es- timating Percentage of Impregnation. — Time required for Hatching. — Progress of the Eggs. — How to tell Eggs that will produce Good Fish. — Transportation. — Packing. — Modus Operandi .... 124-150 CHAPTER III. CARE OF ALEVINS. Hatching of the First Trout. — Duration of Yolk-Sac Pe- riod ; Progress of. — Instinct to hide. — New Instinct. — Indifference to Cold. — Alevins easily Transported. — The Black Crook 151-160 CHAPTER IV. REARING THE YOUNG FRY. SECTION I. — Progress of Young Fry, and General Direc- tions. — When to begin to feed. — Method of Feeding. — Hammerle's Invention for feeding Trout. — Bright Prospects. — The Young Fry dying. — How to save them. — Further Progress 161-182 SECTION II. — What to do to make the Young Fry live : i. Have healthy, well-fed Breeders ; Large Eggs how produced ; 2. Develop strong and healthy Embryos in Egg; 3. Provide Suitable Place for Young Fry. — Points to be secured : a. No Possibility of Water being cut off; 6. New, unused Water essential ; c. Shade necessary ; d. Must not be crowded ; e. Take good Care of Fish. — Scepticism about raising Young Fry. — Discussion. — CONTENTS. Xlll Causes of Death external and removable. — Maxims. — Good Care rewarded 182-193 SECTION III. — Diseases of Trout Fry. — Untrodden Field. — Diseases enumerated : I. Fungus on the Egg ; 2. Par- tial Suffocation of the Embryo ; 3. Strangulation of the Embryo; Seth Green's Dropsy, or Blue Swelling ; 5. De- formity at Birth ; 6. Fungus on the Surface of the Body ; 7. Constitutional Weakness ; 8. Emaciation ; 9. Star- vation ; 10. Ulcers on the Head ; II. Animal Parasites ; 12. Fin Disease ; 13. Black Ophthalmia ; 14. Irritation of the Optic Nerve ; 15. Inflammation of the Gills ; 16. Fatty Degeneration of the Vitals; 17. Spotted Rash; 18. Strangulation by Food; 19. Cannibalism, Nib- bling; 20. Overheating; 21. Suffocation.— Cautions 193-209 SECTION IV. — Filling Orders for Young Fry. — Prepara- tions. — Counting. — Precautions in Travelling . 209-214 CHAPTER V. GROWING THE LARGE TROUT. SECTION I. — Trout in general. — Scientific Description of the Salmo Fontinalis (Storer). — Trout the favorite among Fishes. — Suited to Domestication. — Sight. — Hearing. — Smell. — Habitat. — Peculiarities. — Natu- ral Food. — Age. — Weight 215-228 SECTION II. — Commissary Department. — The right Kind of Food. — Other Kinds of Food. — Care and Prepara- tion of the Meat. — Feeding. — Daily Rations . 228-237 SECTION III. — How to secure the Large Trout against Loss. — Guard against : I. Freshets ; 2. Overstocking; 3. Heated Water; 4. Careless Handling; 5. Can- nibalism ; 6. Fouled Water ; 7. Natural Enemies ; 8. Poachers. — Safeguards at Cold Spring Trout Ponds. — Jack 237-253 SECTION IV. — How to grow Trout to a very Large Size and rapidly. — Directions: I. Give them Plenty of Wa- ter ; 2. Plenty of Food ; 3. Warm Water (relatively) ; 4. Range; 5. Space 253-255 XIV CONTENTS. SECTION V. — Daily Care of the Large Trout. — Little La- bor required. — Mortality slight .... 255, 256 SECTION VI. — Marketing the Trout . . . 257-259 CHAPTER VI. CONCLUDING CHAPTER. SECTION I. — Work in general of a Trout-Breeding Estab- lishment: In Summer; Fall; Winter; Spring. — The Pecuniary View of Trout-Growing — Current Expenses. — Large Margins of Profit. — Estimates. — Risk. — Sale of Spawn. — Young Stock. — Prices Current 260 - 270 SECTION II. — Recapitulation. — Summary of Directions and Precautions in Regard to Water, Ponds, Nursery, Eggs, Young Fry, and Large Trout . . . 270-273 APPENDIX. I. A New Discovery. — Cure for Fungus . . 277-281 II. Journeys of Live Fish and Eggs . . 282 - 286 III. Odds and Ends 287-305 IV. Patent Carbonized Hatching Troughs . 306-308 V. Brief Sketch of Operations at the Cold Spring Trout Ponds 309-314 VI. Salmon-Breeding Establishment on the Mirimi- chi 315-322 VII. Experiments with Trout Eggs and Trout . 323-327 VIII. The Progress of Development of a Salmo Egg ( Coregonus palcza). ( Vogt. ) Translated from the French by Frances W. Webber . . 328-335 IX. Perch Hatching 336-338 X. Organization of the American Fish Culturists' As- sociation 339-341 XI. Specimens of Salmonidae for Professor Agassiz 342 - 344 XII. Marking Salmon (Buckland) . . . 345 - 347 XIII. Are the Fish in the Sea diminishing? (Bertram.) 348-355 XIV. Books on Fish Culture 356-362 INDEX . . ' , ' , ' . . . . . 363-367 DOMESTICATED TROUT. PART I. TROUT-BREEDING WORKS. DOMESTICATED TROUT.* CHAPTER I. INTRODUCTION. WHEN the writer of the following pages asked Seth Green, in 1866, "how many of those who engaged in trout breeding would succeed," he answered, with his well-known quickness of manner, " One in a million." There was so much wanting, at * How fully the word " domesticated " will finally apply to trout that are bred and grown artificially, time alone can decide. It is still a very doubtful question whether they will ever be- come so accustomed and attached to the habitations of man that they will prefer to remain around his homes and under his pro- tection, like dogs and fowls, and so become in the strictest sense domestic creatures. Still, this result is not impossible, perhaps not improbable. Cattle and horses become as wild as buffaloes and deer when left to run wild long enough. Artificial influences have given these creatures their domestic habits. Why may not a sufficiently long course of similar influences create a similar change in the habits of trout ? Trout are not naturally averse to man in their primitive wildness, before they have learned to fear him. I have seen wild trout in the uninhabited forests of New Brunswick as little disposed to avoid man as sheep in a pasture. Why, then, may we not, by taking away their fear of man through domestication, restore that 4 DOMESTICATED TROUT. that time, in the knowledge required to insure suc- cess, that Mr. Green's reply was hardly an exaggera- tion. Since that time, however, the whole aspect of the matter has been changed, and the care and study bestowed on the subject have evolved a set of rules and principles, the careful observance of which will render a degree of success almost certain. I think it may safely be said that the time has come when trout can be hatched, reared, and brought to maturity in great numbers and with comparatively little loss ; and I think it is also safe to say that success in raising the fish will of necessity be accompanied by pecuniary success while the present relations exist between the prices of trout and the cost of the food on which they are reared. primitive state of feeling towards him, which is free from aver- sion? Again, I have at my ponds trout that were hatched from parents that were themselves hatched there artificially. Now, it may have been wholly a fancy, but there has seemed to me to be a difference between these fish and the offspring of wild parents in respect to shyness, and that the artificially hatched progeny of domesticated parents were less shy than the artificially hatched offspring of wild parents. If this is so, and the trout show an improvement in one generation, what may we not ex- pect of fish in which domestication has been hereditary for many generations ? The time may come when continued domestication, together with the overcoming of their fear of man, will so modify the present action of their instincts, that, when pains are taken with the domesticated trout, they will prefer to seek the shelter and food which they find around the homes of men to the precarious chances of a wild and roaming life. This may not be probable, but I do not think it is impossible. INTRODUCTION. 5 I do not wish to be understood, however, in saying that following certain rules will insure success, that a mechanical adherence to rules will make any one succeed. On the contrary, to raise trout successfully demands a vast deal more than that. It requires not only the ordinary force, foresight, and tenacity of pur- pose requisite to success in any business, but also, in an unusual degree, constant vigilance and caution, and that peculiar blending of insight, skill, and precision which makes a successful sportsman, and which seems to be a gift, rather than an acquirement. I do not say that without these qualities a degree of success may not be obtained, but for the best success these traits are indispensable. You can see at once why this is so. In the first place, the trout breeder has to deal with the most elusory, the most treacherous and capricious thing in the world, namely, running water. To make running water go as you would have it and where you would have it, from one year's end to another, through all the vicissitudes of weather of the four seasons, in- cluding the extremes of frost and heat, freshet and drought, is a task the difficulty of which only those know who have tried it. Then it must be remem- bered that your charge is a wild creature, which has never been domesticated or taught domestic habits, and every one knows the vast difference in the difficulty of the work between the rearing of wild and domesti- cated creatures. Furthermore, the trout lives in an element not yours, but foreign to you, and one which you can never by any 6 DOMESTICATED TROUT. possibility learn the nature of by living in it yourself; and lastly, in the earlier stages of its growth the de- velopments and functions of the trout and the progress of its diseases are almost or wholly microscopic, — all of which considerations call for a peculiar watchful- ness and skill. But though so much is required for great success, it is also true that the knowledge which has now been gained of the art will enable most persons to raise trout with very gratifying results, and almost any one in a favorable locality can raise trout enough to feel rewarded for his pains. THE PRINCIPLE OF SECURITY. Before taking up the various branches and pro- cesses of trout raising, I beg to mention one prin- ciple, the most important, in the writer's opinion, of any in the whole prosecution of the enterprise, and one which, on account of its importance, will be im- pressed upon the reader at every favorable opportu- nity throughout this little treatise. This is the prin- ciple of insuring the utmost degree of security in every department of your work. The emphasis with which this principle of security is urged upon the trout culturist will be understood when the following points are considered. i. All you have to do to be successful in trout raising, or to make your fortune from it, if you have a good place, is to keep your fish alive and growing. The hundred thousand trout you hatch this spring, if you keep them thirty months, will bring you thirty INTRODUCTION. / thousand dollars, if you get only thirty cents apiece for them ; and they will be poor trout if they do not bring that. This calculation is very simple, but sound. The fact is, that trout are produced in the first instance in such enormous quantities, and at so little cost, they can be raised with so little outlay of money, and they bring, when matured, such a high price in the market, that all you have to do is to keep the fish alive and growing, and your success will be all you can wish. The prize is already in your hand. All you are required to do is to hold it. Hence the importance of making what you have secure. It is important, because that alone will bring you almost incredible returns ; and if secu- rity alone will make you successful, it must be impor- tant. 2. The utmost degree of security is demanded, be- cause, when losses do occur, it is generally on so large a scale. The peculiar nature of the things you deal with, namely, fish and running water, and the magnitude of the numbers you operate with, are such that there is hardly an occupation in the world where insecurity is followed by such wholesale loss. For instance, the stream that supplies fifty thousand fry is cut off a few hours, we will suppose, in a hot night in summer, by an accident. In the morning fifty thousand trout are dead. It is not the loss of a few, as the farmers in the provinces lose their sheep by the attack of the black bear, or the spring lambs are killed by foxes, but it is the whole fifty thousand. As an illustration of this, a visitor, one July evening, about seven o'clock, 8 DOMESTICATED TROUT. accidentally moved a small gate which regulated the supply of twelve thousand fine, healthy trout fry belonging to the writer, and at half past ten the same evening every fish was dead on its back. The gate was not moved over an inch ; the consequence was the death of twelve thousand beautiful young trout. For instance, again, a freshet that you have not guarded against comes down unexpectedly, and sweeps over your ponds ; when the waters subside, you will not have lost one or two of your fish, but, it is very likely, three fourths of them. Or a screen inse- curely placed may let them all go ; or an epidemic, bred by foul meat, may take off half your brood before you can check it. A score of instances within the writer's knowledge might be mentioned, where actual losses of great mag- nitude have occurred in each one of these ways, when the only cause was insecurity. Thus it is seen that losses, when they do occur, are frequently so disastrous that no degree of security in guarding against them seems excessive. As in business, so in trout raising, the magnitude of the risk calls for a corresponding degree of security. 3. The utmost security is also necessary in trout raising, because the dangers are so incessant and so constantly present. Plant your corn in the field, or turn your sheep out to pasture, and they are tolerably safe ; their dangers come seldom, and their enemies are few ; but hatch your trout in the water, and not a moment, by day or by night, are they free from INTRODUCTION. 9 danger, and there is not a moment when they are not surrounded by mortal enemies. Frogs, lizards, land and water snakes, water-beetles, the caddis-worms, land-rats and water-rats, mice, minks, weasels, kingfishers, herons of several kinds, and even cats, are on the alert for them all the time, and, after they have once found them, will visit them every day or night as long as they last. The unprotected trout are like a flock of sheep in the haunts of pan- thers and wolves on the Rocky Mountains, and have about as much chance of surviving. Their danger is incessant. It is not once a week or once a month that their enemies come for them, but every day and every night of their lives, if they are unprotected ; and every week the number of crea- tures that feed on them will increase. It is surprising how fast kingfishers, herons, frogs, and snakes will multiply around a well-filled and unprotected trout pond. Furthermore, there is the constant danger from the water itself which sustains them, either of its overflowing, or running short, or of getting too warm, or becoming unwholesome, — all which accidents are likely to happen and to be attended with fatal re- sults. The constant presence of these dangers ren- ders it doubly important to make security your first thought in raising trout. 4. This is not all ; the sources of danger to which your fish are exposed are of the invisible, intangible kind, that keep out of your sight and out of your reach, and for that very reason security becomes ten- fold more needful. Many of their dangers come when IO DOMESTICATED TROUT. they are least expected ; they do their work unseen, often in the dark, and leave no trace of their presence. For example, one or two of the fine threads in the screen of your hatching trough may be worn through, or there may be some small undiscovered crevice in a corner of your nursery, and day after day, for weeks, the little creatures may be slipping through and escap- ing, and an immense loss occur before you even sus- pect the cause of the mysterious waste. Or the cover of your hatching trough, although to all appearances tight, may be loose enough to admit a mouse, and every night for a month he and his companions may come into the trough, and feed on your alevin trout in the corners, where they swarm by thousands ; and yet, when morning comes, not a sign or a trace may you discover to show that anything has gone wrong, except that your fish are daily dimin- ishing. Or it may happen that a muskrat, out of sight under the earth, is boring a hole that will let your fish out, when you think they are perfectly secure ; or a mink, wholly unexpected, may have quartered himself in one of your ponds ; or the invisible fungus may, without your knowledge, be gathering in the gills of your young fry, to their certain future destruction. Such is the occult character of many of the dangers which threaten the lives of your trout, and hence the need of extreme security in raising them is such that it can hardly be overestimated. Labor, patience, and constant care are required to be successful ; but the one consideration which ranks above all others is to guard them from every species of insecurity. INTRODUCTION. 1 1 SELECTING THE WATER. The first thing to do, in getting ready to raise trout, is to find suitable water. This is a very important part of your preparations, for it is the element that your trout are to spend their lives in ; and if there is anything wrong about the water, it will sooner or later show itself in fatal results. In looking for suitable water, the following precau- tions should in no instance be overlooked. i. Be sure that there will always be water enough for your purposes. To decide upon this, you must be guided by the amount of water flowing in the hottest week of the dryest time in the summer. This is your guide : the stream or spring is worth no more than what it will do at its very warmest and lowest time. It seems like reflecting on the reader's intelligence to insist on this precaution, yet thousands and thousands of fish have been lost by neglecting it* Great care ought to be exercised to guard against being misled by deceptive appearances. When you see a brook sweeping along in the spring at its flood height, it is extremely difficult to realize that the swollen stream can become, as it often does, a dry or nearly dry channel. Therefore, when you select your brook, either see it yourself in its dryest state, or take the testimony of some perfectly reliable * I once received a letter from a man who wanted to know " what kind of fish he could raise in a brook which was quite large eight months in the year, and dried up wholly during the other four." 12 DOMESTICATED TROUT. person who has seen it thus ; and if from what you see or hear you are led to believe that it is possible for the supply of water to become insufficient, have noth- ing to do with it. Overcome all temptations to try it, and look elsewhere. 2. Be sure that no freshets which can carry away or overflow your works are possible. In deciding upon the character of your stream, in this respect allowance should be also made, as in the former case, for decep- tive appearances, though in just the opposite direction. It is so very difficult to believe that the harmless little rivulet of August can become a resistless torrent in October, that many persons are apt to be misled by the deceptive appearance, and will actually go to work on a stream liable to freshets, and will build ponds, and will stock them, at great expense, with no guar- anty whatever that the next fall or spring flood will not, as it generally proves, sweep everything away. Trust to no probabilities, but make sure that no fresh- ets can come that can do you damage, or, at least, that no such freshet ever has come. If this is not made sure of, a single night will destroy the work of years. Brooks subject to moderate freshets that can be controlled are not necessarily objectionable ; they need not be given up, if the expense of carrying off the sur- plus water is not too great ; but a brook where the freshets cannot be wholly guarded against is a delusion and a snare, and ought to be utterly avoided. 3. Be sure that the water does not heat up in the summer to an unwholesome point. Many brooks which have the appearance of being perfect trout INTRODUCTION. 13 streams are worthless from becoming too warm in the summer. Here, also, the test should be the hottest day of the dryest time. For it should be remembered that one day of freshet, drought, or intense heat may do as much mischief, in taking away your trout, as six months of the same might do. The waters otherwise suitable, which are most to be dreaded on account of their excessive heat, are outlets of ponds or lakes, and such as are at the fish preserves distant from their sources. These waters, though peren- nial and of even flow, and fed by springs, may yet, from too much exposure to the sun or air, be wholly unfit to keep trout alive, by reason of their temperature rising too high. This objection is not always so imperative as the other two just mentioned, because there are two ways of obviating it to some extent, viz. : — i. By putting ice in the stream. 2. By taking the water fiom near its source, through a pipe under ground. The first remedy often involves so much risk, as well as expense and necessity of constant vigilance in hot weather, that it had better not be contemplated, except in cases of great counterbalancing advantages. The latter remedy, however, when it will pay, is usually practicable, and will do if it can be made safe. But, at all events, make sure either that the water will keep cool of itself, or that you can and will keep it cool enough by one method or another. Under this head it may be suggested that the quan- tity and force of current and vigor * of the water have * I cannot exactly define the word " vigor " in its present ap- 14 DOMESTICATED TROUT. much to do with the degree of temperature at which trout will live. For instance, when water does not pos- sess much vigor, is deficient in quantity, and sluggish, it will not support trout life in so high a temperature as when it is vigorous, plentiful, and rapid. I think it is safe to say that sluggish flat water at 70° is dangerous, if not fatal, to trout ; while they will live in vigorous rapid water which occasionally runs to 80°. I have found 85° to be fatal to them in all kinds of water. 4. Be sure that the water you select is intrinsically favorable to trout. Be very careful about using any brook or spring which can possibly receive the dis- charge of a tannery or mill, or drainage discharging any poisonous substance. The presence of some lime in the water naturally is not necessarily an objection ; for trout do live in limestone regions, and in water having some lime in it. So of iron ; but too much of either in the water will kill them. The best test of this point that you can possibly get is that the stream is a natural trout brook. On the other hand, if it is not a natural trout brook, or has not been one, be very shy of it ; there is some good cause why trout do not inhabit it, and the cause is probably to be found in the unsuitableness of the water. It is no objection to a stream where trout are raised that it is occasionally turbid, or even muddy. Such plication, nor can I find a better word to give my meaning. In drinking water, we distinguish between that which is flat and that which is sparkling. What we call sparkling water, when we drink it, I mean by vigorous water in a trout brook. There are very great differences in this respect, as all are aware. INTRODUCTION. 15 water, though injurious to eggs, is wholesome and beneficial to the fully formed fish of all ages. It is always a good precaution, where a stream is used which has no trout in it naturally, to put in a few and keep them there the year round, and see how it suits them, before adopting it fully as a trout-breeding water. There is some conflict of opinion about the compar- ative value of spring and brook water for raising trout. As a rule, I think generally, all things considered, that spring-water is best for hatching, and brook-water is the best for raising trout. It is said that brook-water is more natural for hatching ; that it hatches the trout out at a better time, namely, in the spring, and that the young fry, when they do come out, are uncommonly lively. It is not certain, however, that brook-water is more natural than spring-water for hatching, for in many brooks, and in most of those with which I am acquaint- ed, half the fish lay their eggs in spring-holes, or so near the spring-sources of the stream that it is practically spring-water that they are hatched in. Then, again, it is a doubtful advantage, if any, to have them hatch late ; and lastly, they are not sure, by any means, to make better trout for being unusually lively in the earlier days of their infancy. On the other hand, spring-water possesses, for hatch- ing, the vast advantage over brook-water of being safer. I think that in hatching, except in very rare instan- ces, brook-water can have no advantages which can begin to offset this great counterbalancing advantage of safety. You cannot be too sure of the water which flows over your eggs. In most brooks you cannot be 1 6 DOMESTICATED TROUT. sure that there will not be trouble in the course of the winter from a stoppage of water, an overflow, sediment, or injury to the water above. At any rate, with a brook, your risk, on account of these dangers, is vastly increased. But with a spring there is an even flow, a steady temperature, very little danger of stop- page of the water or injury to it, and the whole thing is compact and well in hand. These considerations will, in the long run, give the spring-water for hatching purposes a very decided ad- vantage over brook-water. Brook-water, again, is best to raise trout in. Spring- water, just emerging from the darkness of the interior of the earth, is cold, wholly free from animal and vege- table life, and deficient in that peculiar vitality which its flow through the open air and sunshine imparts to it. Trout will not grow fast, will remain small, and will develop small ova, in such water. Brook- water, on the contrary, possessing the qualities which spring-water lacks, is much more nutritious, if I may use the word, will grow trout rapidly, will give them a good size, and will develop large eggs in the fish. For these reasons it is, if safe, better than spring- water for raising trout. It should be mentioned here, however, that cold wa- ter makes a hardier and firmer-fleshed fish, and is less favorable to disease. It is consequently better, some- times, when there is any tendency to disease, to keep the very young fry in the spring-water until they have acquired some firmness of bone and flesh. The best water advantages of all are perhaps found INTRODUCTION. 1 7 where loth spring and safe brook water are at one's command, and either or both can be employed at pleasure.* The brook-water can then be used, if de- sired, while it is safe, and a mixture of spring and brook can be so graduated as to make the eggs hatch at any desired time between the minimum and maxi- mum periods of incubation. In the long run, however, I think experience will prove that a large spring of even temperature and even flow is about as good as anything for hatching the eggs. * This is the case at the Mirimichi Salmon-Breeding Works. CHAPTER II. PONDS. THE first questions you will ask yourself, when you have decided that you have suitable water for your purposes, are, where shall the ponds be located, at what points on the stream shall the ponds be built, and how shall they be constructed ? In answering these inquiries, a great variety of con- siderations of a special character will come in, such as the nature of the soil, the lay of the land, and your personal tastes, which you can best settle for yourself without help ; but there are other considerations of a general character which should be noticed here, and among them are the following. i. The water you have is to be used for three dis- tinct purposes, — for the hatching apparatus, for the nursery, and for the ponds of the mature trout, — and it should be borne in mind that the water which may be good for one of these may not be good for another. For instance, the cold, barren water, just emerging from the earth, though just the thing for hatching eggs, is, from its cold and unnutritious character, poor Water to fatten mature fish in ; on the other hand, brook-water, full of animal life, which is just the thing on that account for the mature trout, may, from its PONDS. 19 liability to sediment, or intractable character, or other causes, be extremely unsuitable for hatching. In locating your ponds, then, these three departments should be kept distinct in the mind ; and it should be remembered that the works belonging to each should be so built in reference to their distinctive require- ments, and also with reference to each other, that, when they are finished, each will have its proper water advantages, the precedence, when there is choice of water, being always given to the first two named, the hatching apparatus and the nursery. Nature has done so much in some trout-pond localities that very little foresight is required in this respect ; but in many, especially where the water has to be used over once or twice, the exercise of considerable forethought will be well repaid. 2. Get your ponds, whenever you can without great inconvenience, either wholly or partly by excavating the earth, rather than by damming up the stream. This is for safety ; with the bulk of the water above the level of the adjacent land, you are never secure. I never saw a trout-pond dam in my life that I con- sidered absolutely safe. Recollect that muskrats, frost, and decay are the active enemies of your pond walls, and their work is correspondingly mischievous in the degree that the ponds are raised above the level of the surrounding land. As I said, I never saw a trout-pond dam that was safe to hold trout in ; but I have seen more un- safe ones than I can think of, that sooner or later led to disastrous losses by breaking aw-ky-aad.. letting out 2O DOMESTICATED TROUT. the fish. Excavated ponds are the only safe ones. Let your rule be, when possible, to excavate rather than dam up. 3. Build your ponds as compactly as possible. This might be said of your whole establishment also. Have all your ponds and works as near together as other more important considerations will allow. In rainy weather, and deep snows, and times of danger, you will appreciate this. 4. Build all your ponds small that mean business. Never break over this rule. Make your ponds for sport as large as you please, and I should say the larger the better ; but when you mean business, build small. The greatest nuisance in the world, in a trout- breeding establishment, is a large pond, where the trout are out of control, and do as they please, and go as they please, wholly regardless of your convenience. This rule should always be observed, namely, never to let a trout escape to any place where you cannot get at it, observe it, and capture it at a moment's notice. It is just as ridiculous, in the present stage of trout- breeding at least, to turn out your trout in a large pond, where they can get away from you, as it is to turn out your sheep or cattle in an unfenced moun- tain-pasture, where you will never hear from them again unless you fit out a regular hunting expedition to look them up. In course of time, when trout become as plentiful as the cattle and horses in South American pampas, this will do, perhaps ; but now, when trout are as scarce as they are, and worth a dollar a pound, you want to have them where they cannot PONDS. 21 possibly get away from you, or even permanently out of your sight ; consequently, your ponds should be built small. 5. Have a fall, and as much of one as you can, at the head of each pond ; this is not essential, but very desirable, as then the water comes full of air and life directly on your fish, which is worth a great deal. You can keep more fish in the pond by it, they will be healthier, and will grow better. 6. I think it is a good plan to locate your ponds far enough from the fountain-head of the stream for the water, by running through the air and sunlight, to have changed its character from cold barren spring-water to warmer and more nutritious brook-water. It will soon acquire this brook character, especially if it is spread out over considerable surface. Indeed, a pond having a large surface exposed to the sun, built directly over the spring, answers very well ; but trout will not grow fast or fatten easily in a deep, small spring-hole or spring-water pond, not much exposed to the sun. Do not infer from this that trout need to be in the sun ; it is not the trout, but the water that the trout live in, that requires the sunlight. Brook-water which has a good deal of sunlight in it is better for ponds than spring-water with none. Trees are to some extent ob- jectionable, when their leaves make trouble by clogging up the screens, but they are very desirable for shade. 7. If your dwelling-house for yourself or keeper is built, then try to locate your ponds as near to the house as possible, within sight at least. If your house is not built, then build it very near your ponds. 22 DOMESTICATED TROUT. You are never entirely safe from poachers, it is true, but your security is much greater for living near your ponds. Herons, kingfishers, minks, and other destructive animals, are also less likely to frequent your ponds if your house is near. Then, besides the general advantages of always being near, and having your ponds in sight, you will many times, when a sudden shower comes up, or in some other case of need, go to the ponds, when, if you lived farther off, you would, perhaps, not think it worth the while. In the course of time the lack of this advantage will surely show itself in your record of losses. 8. You cannot exercise too much caution in making your ponds secure. To this end, I would recommend that every pond and every aqueduct on your place be built of two-inch plank. Had I followed this rule when I began five years ago, I should have saved thousands and thousands of fish. I have had all sorts of ponds and dams, and have had them built by experienced workmen, and warranted to stand twenty years ; but not a single pond has held, out of twenty- three that I have built, except my plank ponds. Some of them have stood for five years to perfection. Mean- while, there has been no end of vexation, annual ex- pense, and loss, caused by the other ponds breaking away ; and if I began over again, I would build every- thing from beginning to end, that the water flowed through, of two-inch plank. Stone, concrete, cement, and similar substances, may answer as well, perhaps, for single ponds ; but for a material to be used through- PONDS. 23 out I prefer plank, because it can always be de- pended upon, repairs can be easily made, a screen can be readily put in anywhere, a tight joint can always be formed without trouble, tighter and more convenient connections can be made with the streams, and, on the whole, it stands the test of time and weather, and of both the routine and emergencies of experience, bet- ter than anything I know of.* If you object to the want of durability of wood and its unsuitableness for fish, char the plank an eighth of an inch deep all round, and then you have both a dura- ble and a suitable material. I do not, however, insist upon the necessity of using plank, if you think you have something better. I only give the lessons of my own experience ; but, what- ever you use, be sure that it is safe, that it will resist the muskrats, the weather, the frost, and the natural tendency to displacement, which, I suppose, all materials in the earth or on its surface are sub- ject to. If it is necessary to build a dam, I would recom- mend to the inexperienced to procure, by all means, the skill of an engineer, or practical dam-builder, who understands the nature of running water ; for to con- fine running water securely is an art in itself, and a beginner is almost sure to make a mistake somewhere, for which in the end he will pay a heavy penalty in losses. Running water is the most treacherous of all things, * These remarks are intended, of course, for business ponds. It does not matter much what amateur ponds are built of. 24 DOMESTICATED TROUT. and is always seeking to run in a different channel from that artificially provided for it ; and if there is a weak spot anywhere about the sides of the dam or pond, the water will find it, and sooner or later, with the help of muskrats and frost, will bore a hole through it, and very likely this will happen in some place where you have never dreamed of its going. Once having gained an advantage, it never loses it, but will render your pond more and more unsafe, till you make an entire reconstruction of it or aban- don it. Employ an experienced man, then, to build the dam, if you must have one, and tell him to make it doubly safe; and even then, if your experience is like mine, you will be sorry you built it. 9. The shape of the ponds should be adapted to your water supply. If you have plenty of water at a low temperature, build the ponds of any shape you like so that they are not too large. If your water supply is small and cold, make your ponds narrow and shallow. If the supply is small, and liable to heat up, make them narrower still, and deep. Indeed, a deep ditch is the best thing where you have neither cold nor plentiful water. With average water, experi- ence favors oblong ponds, not over twelve or fifteen feet in width, nor over three or four feet in depth, and of any desirable length ; these ponds can be easily inspected, easily swept with a seine, and will have no places of concealment for the fish to hide away in. I think it is a good plan to have the ponds deepest PONDS. 25 in the middle, and to diminish in depth towards both ends, so as to grade off to nothing at the inlet and outlet. Such ponds keep the cleanest. If the pond is deep at the lower end, in the course of years a good deal of refuse and unclean matter will collect there, which you would rather have out of the pond, and which would have naturally worked off at the outlet if the bottom of the pond gradually shelved up to- wards it. 10. Always, if possible, have your ponds so ar- ranged that you can draw off the water, if necessary. When you want to make repairs or changes in the pond, or wish to clean it out, this will be found a great convenience ; but it is especially serviceable when you want to use the pond for smaller fish than have been living in it, for it is never quite safe to put small fish in a pond which has been stocked with larger ones, unless it is drawn off. Trout have such a wonderful faculty for getting out of sight, that even in the best-constructed ponds, where the water is not drawn off, they will often elude your search, and one or two fish may still be left in the pond after you have, as you believe, examined it thor- oughly and taken them all out. I need not say how mischievous the mistake would prove. Instances could be cited of hosts of small fish having been de- stroyed by one or two large ones, left unwittingly in the pond. Therefore have your pond, if possible, so that you can draw it off if required, and always do so when you are going to substitute small fish for large ones in it. 26 DOMESTICATED TROUT. ii. Allow no hiding-places in your pond which you cannot remove at pleasure. They almost always lead to mischief. A dead fish, perhaps, will get in them without your knowledge, and foul the water ; or a mink will make use of them, and elude you for weeks, or, more likely than all, a large cannibal trout will hide there and prey on the smaller ones for months, undis- covered by you. On the other hand, provide all the movable hiding-places within your control that you •please, — the more, up to a reasonable extent, the bet- ter, — but never let them get out of your control, or exist without your having access to them. The safe- guards against outside dangers, which all ponds should possess, are very important, and would, perhaps, more naturally come in here, but they will be considered under the head of " Growing the Large Trout." * NUMBER OF PONDS. There is no regulation number of ponds for a trout- grower to be governed by. The best rule is to build all you want ; the usual number, three, recommended in books, being no guide to go by. You will certainly want three, and probably several more. I have often found ten quite few enough. You may be sure of this, that you will in time have two sizes of young fry, two sizes of yearlings, and at least three sizes of older ones, which should be kept apart. Besides the ponds for these, you will find a minnow- pond, a pond for rare fish,f and two or three experi- * See pp. 245-253. t At the Cold Spring Trout Ponds there is a pond twenty feet PONDS. 27 ment ponds convenient. I should say, build all the ponds you please, if you have water enough ; you will not have too many. SPAWNING BEDS. The spawning beds consist simply of a long narrow flume, or raceway, at the head of the ponds, where the fish come up to spawn. They should be built at the very upper end of the pond, and should have a good current of water running through them. They are generally made of plank, and should be at least thirty feet long, with sides eighteen inches deep. From the lower end of the spawning beds, the slope should be gradual to the lowest level of the bottom of the pond. If the slope is abrupt, the fish are not so likely to go up the races, and are more likely to spawn in the pond. The width of the spawning race will de- pend on the volume of the stream, it being an essential point to secure a lively current over the beds. Where there is plenty of water, the raceways should be four feet wide. If the water supply is small, two feet, and even eighteen inches, will do. There should be trans- verse bars placed on the bottom, across the whole width, high enough to make the water above them from four to twelve inches deep. The more water you have, the deeper you can afford to make the water in, the beds, without dulling the current too much. square, called the happy-family pond, where nine different kinds of large fish are kept together, including glass-eyed pike, mul- lets, black bass, and others. Although not profitable, I have al- ways found it sufficiently interesting to make it worth while to keep it up. 28 DOMESTICATED TROUT. In the spawning season, a layer of coarse clean gravel, three or four inches deep, should be thrown into these beds. They should be closely covered, and generally your whole force of water turned on. The trout will come up here to spawn in preference to any other place in the pond, and it is here that they are trapped for the purpose of expressing their eggs. The continued daily disturbing of them for this pur- pose will sometimes — and usually, I think — drive them down the stream a little lower, towards the end of the season. It is therefore a good plan to cover and prepare only the upper half of the beds at first, and to trap the fish there at the beginning of the season, so that when they fall back, on account of being disturbed, they will not drop far enough down the stream to spawn below the lower beds, which, when the proper time comes, can be made ready and covered like the rest. We have thus far treated wholly of the artificial method of taking the eggs. This method has two ob- jections. It is entirely artificial, and it involves severe work, and exposure to water in the spawning season. To obviate these two objections, Hon. Stephen H. Ainsworth conceived the very ingenious plan of mak- ing the fish spawn naturally, and at the same time of saving the eggs. This idea he carried out in what is now everywhere known as the Ainsworth Spawning Races. The following description of this invention is by the inventor, Mr. Ainsworth. PONDS. 29 AINSWORTH'S SPAWNING RACE. This race may be built like the races made for the artificial impregnation of spawn used by nearly all trout-breeders to en- tice the trout up from the pond to spawn. It can be made of any length, from ten to fifty feet, and from two to six feet wide, according to the number of trout which are to use it and the amount of water for the supply of the pond. It should be made with plank sides and bottom, so tight as to keep out all sedi- ment. Paving the bottom nicely with small stones will answer. The bottom, whether of plank or stone, must then be covered with a half-inch layer of fine, well-washed gravel. When one has large trout to spawn in the race, the water should be two inches deep at the upper or supply end, and fif- teen inches deep at the lower end, where it empties into the pond, with a gentle current throughout its whole length. This will give good spawning depth to the water for trout of all sizes from six to twenty-four inches long. Usually a race three feet wide, and from fifteen to twenty feet long, will be quite sufficient for a pond of one thousand or eighteen hundred trout. The bottom of this race must be covered with fine wire-cloth screens, of about ten meshes to the inch, made of zinc or galvan- ized wire, so as not to corrode the spawn. Iron wire, if painted, will answer where zinc cannot be obtained. These wire screens must be nailed to wooden frames made of inch-square stuff, the frames to correspond in length with the width of the race, and to be as wide as the cloth will permit, — say two feet. Strips of 1-inch stuff must be nailed to the bottom of the race for the screens to rest on, in such a manner that they will be raised a quarter of an inch above the gravel on the bottom. This is done to give good circulation to the water under the spawn as they fall on to these wire screens. These screens must be laid the whole length of the race, side by side, to catch the spawn as it is deposited by the parent trout. Now, place over these another set of screens made of coarse wire-cloth, of about two or three meshes to the inch, so that the spawn will drop through easily. These screens must be nailed 3O DOMESTICATED TROUT. on frames of the same length as the others, but of two-inch stuff, and as wide as the cloth will permit. These screens must be strong enough to hold two inches of well-washed coarse gravel, from three quarters of an inch to two inches in diameter. They should be so large that there will be interstices between the gravel large enough to let the spawn pass down, if necessary, to the lower screen. The upper screens should have handles on each end to lift them by, as they will have to be taken out and replaced every few days during the spawning season. When these two sets of screens are placed the whole length of the race, and all is complete, the water will pass over all, two inches deep at the supply end and fifteen inches deep at the lower end, with a moderate current through the whole race. The reader will perceive by the description and diagram that there is one inch of space between the two screens to hold the spawn as they are deposited by the parent trout, with a gentle current passing over and under them ; and that the upper screen prevents the spawn from being destroyed by trout and insects, so that they are perfectly safe until removed to the hatching box. When the trout is ready to spawn, she will enter the race from the pond and prepare her nest. This she does by whip- ping all the sediment from the gravel with her tail, and then she whips or digs a hole in the cleansed gravel about two inches deep, or down to the upper screen, and about four inches in diameter. She then bends herself down in this hole and presses her abdomen on the gravel, and forces out from one hundred to five hundred spawn, which fall to the bottom of the hole and down through the upper screen to the lower one. She then passes up the race, and the male trout attending her comes over the nest and spawn and ejects his milt on the ova ; he then whips the water in the hole with his tail, sending the water and milt in all directions, so that the milt reaches all the spawn on the screen or in the gravel, and, as they are ripe and ready for the milt, impregnates every one of them. As soon as this is done, the mother trout returns and covers up the spawn and fills the hole, and soon digs another in like manner, and so on PONDS. 31 till she has deposited all her ova, which sometimes takes two weeks. There may be from twenty to fifty trout in the race spawn- ing at one time, and all, or nearly all, of the spawn will be found perfectly impregnated and fully matured, so that they will all hatch, if taken out every three days, or once a week, and placed in hatching boxes. To take the spawn from the lower screens, first take out two of the upper screens with what gravel is upon them ; then re- move the lower ones, and wash the spawn off into a large pan of water carefully, and replace one set behind you, and then take up one set at a time and place back, until all are returned. Should any spawn remain in the gravel, by raising the screen up and down a few times they will drop down through the inter- stices. The race must be kept well covered during the time of spawning, all persons must be kept away, and the fish disturbed as little as possible. By this method the spawn are all saved, are perfectly ma- tured, are all impregnated, and will all hatch ; the young will be perfect, few or none will die, as their sac food is complete, and they will be strong and healthy when they commence seeking food for themselves. It is much less work to take the spawn than by handling, and no parent trout are lost. The spawning race above described answered its purpose perfectly in making the fish spawn naturally, and also lessened the work of getting the eggs. The tending of the races, nevertheless, required considerable labor and exposure. This latter objec- tion was ingeniously surmounted by Mr. A. S. Collins, the partner of Seth Green, in a modification of the Ainsworth Races, known by the name of the Roller Spawning Box. I give a description below, written by the inventor. 32 DOMESTICATED TROUT. Fig. i is a spawning box, with a portion of the side removed. FIG. i. A is a double row of coarse wire screens ; B apron of fine wire cloth ; D a screen ; F a screen. ROLLER SPAWNING Box. For taking the nattirally impregnated eggs of Brook Trout, Salmon, etc. (Patent of A. S. Collins.} In the Roller Spawning Box the principle used is that of the Ainsworth Screens, and the improvement consists in a new and convenient method of collecting the eggs. A double row of coarse wire screens (three meshes to the inch), eight in number, each two feet square, are put together in one frame, eight feet by four. These screens are to be rilled with coarse gravel, and the eggs pass through as in Ainsworth's Screens. Under these is an endless apron of fine wire-cloth, passing over rollers at the two ends of the box. This apron is about one inch beneath the upper screen, and is kept from sagging by small cross-bars, corresponding to the division of the upper screen. These cross-bars are supported by, and, when the rollers are turned, slide on, an inch-square strip nailed to the side of the box. A similar strip, one inch above, supports the larger screens. PONDS. 33 The cross-bars also keep the eggs from being carried down by the current. By using two small bevelled cog-wheels the front roller can be turned by a handle. As the roller is turned for- ward, the endless apron moves with it, and the eggs, as they come to the edge of the roller, will fall off. The pan is placed in front of the roller, and receives the eggs as they fall. The box need not be more than two feet deep ; the depth depending upon the size of the rollers, which in a short race may be quite small, and the box not more than eighteen inches deep. The box is set directly in the raceway, and intended to fill it completely. The water may either enter with a fall over the top of the box, or the top of the box may be cut down until the water will enter on the level at which it is intended to stand over the screens. Fig. 2 is an enlarged view of the front of the same box. FIG. 2. A is a double row of coarse wire screens ; B apron of fine wire cloth ; C pan to receive the eggs ; D screen ; E catch to hold screen D when raised. A screen, intended to prevent the fish from running beyond the race or getting into the lower part of the box, may extend to the bottom, or be arranged differently ; a screen placed at the front of the box is also intended to prevent the fish from getting below. When the eggs are to be taken, this screen is raised on hinges to an 34 DOMESTICATED TROUT. upright position, and confined by a spring catch or latch. This confines the fish which may happen to be in the race, and none of them can get below. The pan is then lowered to its position, the roller turned, and the eggs taken. When the operation is fin- ished the screen is again lowered, the button turned, and the work is done. If the box is wide, say four feet, it is more convenient to have the pan made in two or three sections, inserted in a light frame, as the eggs can be more easily carried in and poured out of a shorter pan. It is better, perhaps, to make the screen to open in the middle, having hinges at both sides. Then one half will keep the fish in the pond, and the other half the fish in the race, from running into the well. The box can be made of any length from four feet to forty feet, and of any width from two feet to six or eight. If it is made very wide, an additional longi- tudinal support must be provided for the revolving screen. We recommend the following dimensions for speckled-trout races : two feet wide, and from ten to twenty feet long ; or four feet wide, and from twenty to forty feet long. The upper screens may be made in convenient sections, the whole width of the box, and six or eight feet long. The end screens are so made that while a full current is per- mitted to flow over the upper screens, only a gentle current can flow through the under part of the box. This current is meant to be so regulated that when the pan is placed about an inch from the turning-roller, all the small stones which the trout may whip through the upper screen will fall short of the pan j the eggs, being lighter, will be carried by the current into the pan, while a great part of the dirt, etc., which may collect on the under screen will be carried up over the pan and entirely out of the box. The revolving screen may be made of tarred muslin or mosquito-netting. But wire-cloth (of ten or twelve meshes to the inch) keeps much the cleanest, and we are inclined to think it best for the purpose. I make my aprons half wire-cloth and half tarred muslin, furnishing the wire only with cross-bars, and always leaving it uppermost. This apron is fastened around the rollers by a lacing of cord. At the end of the season the water in the pond can be drawn down a foot, and everything taken out PONDS. 35 but the rollers. Give the screens a coat of paint or gas tar, and lay them away in a dry place until the next autumn. A stiff brush may also be placed under the forward roller, so that every time the roller is turned to remove the eggs the screen will be perfectly clean. The box can be so arranged that the rollers also can be re- moved each season ; and this arrangement on various accounts is much the best. This box looks, at first sight, somewhat complicated, but is in reality very simple, and easier to make than to describe. Any one who has the knack of using tools can make one which will answer the purpose perfectly. The cost is very little more than that of the Ainsworth Screens (of the same area) as generally used. The cost for wire being the same in both cases, the lum- ber in the box itself being extra, and also the rollers, hinges, and cog-wheels (or windlass wheel). A few of the advantages of the plan are as follows : Let us compare a double row of forty Ainsworth Screens, each two feet square and occupying a space in the raceway forty feet long and four feet wide, with one of the new spawning boxes of the same dimensions. ist. By the old way it would take two men a good half-day to remove the screens singly, feather off the eggs in a careful man- ner, and return each (double) screen to its proper place. It would take the new spawning box about fifteen minutes to do the same work with one man. 2d. The weight of the gravel which has to be lifted in the old way every time the eggs are removed amounts to many tons in the course of a season. In the new box the gravel is not lifted at all. 3d. By the old way the operator's hands must of necessity be more or less wet during the whole operation. Now, as the trout and salmon spawn during the winter season, when the thermom- eter generally stands below the freezing-point, taking eggs in the old way is not only inconvenient and painful, but often impos- sible. By the new-way the hands are not made wet, and may be kept comfortably gloved. 36 DOMESTICATED TROUT. 4th. By the old way more or less of the eggs are lost by care- less feathering, exposing the eggs to the freezing atmosphere, clumsiness in handling the screens (caused by cold fingers), tipping of the screens, wash of the current, etc., etc. By the new way every egg is saved. 5th. By the old method every fish is driven out of the race when the eggs are taken. Some of them will not return, but will seek a spawning-place in the pond, and many eggs will be unavoidably lost. By the new way the fish are not driven from the race. And as the boxes are always covered during the season, the fish will not even be disturbed. In fact, they may spawn while the eggs are being taken, and yet not a single egg be lost. This Spawning-Box answers for securing the naturally im- pregnated eggs of salmon, salmon trout, speckled brook trout, whitefish, shad, etc. It is recommended by the leading piscicul- turists of the country. Mr. Ainsworth's idea was one of great value, and Mr. Collins's device an excellent modification of it, and I cordially recommend their methods to those who wish to avoid the labor and exposure of taking the eggs artificially. No one who has not had experience in taking spawn by hand can conceive of the amount of labor and hard- ship which this beautiful contrivance saves. There is some difference of opinion as to the question which yields the most eggs, the artificial or the screen method, and the results of some experiments of Mr. F. Mather seem to be adverse to the Ainsworth plan.* I will not express an opinion here on this point, but will say that the saving of exposure by the Collins Roller Box is worth paying a good many eggs for. * See American .Agricultural Annual, 1871, p. 94. PONDS. 37 INLETS AND OUTLETS. 12. The inlets and outlets of your ponds should be ample, and securely "jointed," if I may use the word, to the ponds ; that is, so joined to the side of the pond that no water will ever work its way under or around them. This is so simple and safe a process with the plank system, that the advantages derived from this alone would decide me in favor of the use of plank ponds. The outlet is usually a plank trough, or bulkhead, with a screen to confine the fish, and the inlet is the same, except that one half the floor of the bulkhead is made to project over the pond, and is formed of hard-wood slats, laid longitudinally with the length of the bulkhead, and a quarter or half an inch apart. This is much better than a screen, because, while it answers the same purpose in confining the fish, it lets through all the food from above, and does not get so easily clogged up. When a bulkhead inlet or outlet is made to a com- mon earth pond, great care should be taken to have piling driven down to the hard pan below, and on both sides, for several feet ; and even then in some soils the water will work through it in the course of years. Be sure to make the outlets broad enough to admit a screen of sufficient size to carry off all the water at its highest possible flood height, making large allow- ance, also, for the clogging up of screen. Always have a gate at the inlet which will wholly shut off the water in case of danger. 38 DOMESTICATED TROUT. SCREENS. Screens hold a very responsible position in trout culture. All that separates your thousands of fish from the outer world, where they would be lost to you. is the twentieth-of-an-inch barrier of wire-screen. As far as their voluntary escape is concerned, the wire-screens stand in the place of gates, locks, bolts, and bars. It is obvious how responsible their office is. All screens should be of copper or galvanized iron. Copper is best for fine-mesh screens, galvanized iron for large meshes. Wooden slats answer very well for grown-up trout. In using slats it should be remembered that a fish, by turning on its side, will go through a surprisingly narrow aperture, if it is long enough. A square mesh of iron will hold fish securely, when slats would need to be only half the width of the mesh apart. The wire netting should be fastened on to firm frames, and the frames should fit tight in their place, especially at the bottom. Thousands of fish have been lost by neglecting this simple precaution. There should be eighteen threads to the inch for the very smallest fry, four threads to the inch for year- lings, and two to the inch for two-year-olds. For placing the screens for the young fry, see p. 59. If leaves or other debris coming down the stream make trouble by clogging the outlet screen, you can protect it by building out a board frame, say a PONDS. 39 foot deep, in front of the screen, with about eight inches of its width below the water and four inches above ; this will catch and retain the obstructions float- ing down, and the screen will remain comparatively clean. Where it is practicable, it is a good plan to have all the inlets and outlets of the ponds of the same size, so that the screen of any one will fit all the rest. This secures uniformity of size in the screens, and is often a great convenience when it becomes desirable to move a screen from one pond to another. When there is danger of too much water, have a side channel provided to carry it off. This channel should be considerably lower than the inlet to your pond, should be the channel the stream would naturally seek when shut off from the ponds, and should be very ample. I would have it, for safety's sake, double the capacity of any freshet that was ever known on the stream. For the want of this precaution, trout enough have been lost, within my own knowledge, to make a fortune. It is usually the best plan to leave the natural chan- nel of the brook for the surplus water, and to build your ponds on one side of it, and take off the water supply for them from the brook. This is the way the breeding ponds at the Cold Spring Trout Ponds are arranged, and it is the safest way in time of a freshet. CHAPTER III. BUILDINGS. THE hatching house is the one essential building in fish breeding ; but a thorough trout-breeding es- tablishment should have, besides the hatching house, several other buildings or rooms, as, for instance, a meat-room, carpenter's shop, and ice-house. It is not, of course, necessary to have a separate building for all these, but each one should have at. least a separate room. The reader inquires at once, I suppose, why the hatching house will not answer for all of these pur- poses, except, possibly, the ice-house. The reason is this ; if you engage in hatching on any considerable scale, you will have water running through the house in great quantities, half the year, and perhaps all the year round. The result will be that this house will be the dampest place you ever were in, and everything in it, that moisture can hurt, will be spoiled. Tools will rust, the firewood will not burn, the kindlings will be soaked, your scales, microscopes, matches, pails, pans, and papers, — everything, in fact, will become intolera- bly damp. Then, again, the hatching house, being built for the use of water, should not contain anything that would BUILDINGS. 41 restrict the most perfect freedom in its use. If it is essential to turn a stream of water over some fish, in an unusual place in the house, for a week or so, there should be no such obstacle in the way of it as the danger of exposing tools, or microscopes, or any uten- sils, to too much dampness. Therefore I would have the hatching house, or hatching room, devoted to the water, and have all other considerations so subordinate to this that you can deluge the house with water at any time you like, without doing any harm, and without any feeling of restraint, on account of things in it be- ing injured by the dampness. This is the reason why it is not best to use the hatching room for the other purposes mentioned. The buildings or rooms which I would recommend are, a meat-room, an office, a storeroom and carpen- ter's shop combined in one, and an ice-house. i. The meat-room. You should bear in mind that a stock of ten thousand large trout will consume at least forty pounds of meat a day ; this is over a thou- sand pounds a month. This food must first be cut up, and some sorted out for the young fry and some for the old trout. Then the meat for the large fish must be run through a coarse meat-cutter, and that for the small ones through a finer one, and the meat must be kept thawed out in the winter, and fresh in the sum- mer. This handling of the meat, sometimes a thou- sand pounds in a month, sometimes more, and keep- ing it in the right condition in all seasons, is no small task, and unless it has a separate room devoted 42 DOMESTICATED TROUT. to it becomes an intolerable nuisance, especially in the decomposing heat of summer. I would then, by all means, have the meat-room by itself, and here in this room, and nowhere else, should be kept the two meat-cutters, with their stands, the meat-grater (if you use one) for the young fry, the meat- bench, the pails, pans, and baskets for holding and car- rying the meat, the meat itself, and everything else, in short, that belongs to the commissary department, — in this room, and nowhere else. The most disagreeable feature about trout-breed- ing is the commissariat ; and the more you keep it by itself, and out of sight, and out of the way of every- thing else, the more desirable your place will be, and the better you will like your work. The meat-room, like the other rooms, should have a plank floor, with a trap-door in it, should be well ven- tilated, should have a tank of water in it, supplied by a stream large enough to keep it from freezing in the winter and heating up in the summer, and arranged so that the whole stream can be turned on to the floor when it is cleaned or " swashed," — which should be often, — and whatever other conveniences may be de- sired. The tank is not only to furnish water to keep things clean, but it will be found to be the best place in the summer to keep the meat, and the only place in win- ter. I have tried both the ice-house and the spring water for this purpose, but have found that the spring water answers much the best in practice. 2. The next most important room is the store- BUILDINGS. 43 room and carpenter's shop combined; these can be together as well as not. They are required, because a great amount of lumber, old screens and screen- frames, pails and pans not in use, and a thousand other things, will collect about the place, which you will want to have under cover and in a dry place. Then there is so much little work constantly to be done, — what is called in New England "puttering," — that a carpenter's bench and tools are almost indis- pensable, the more so because what needs to be done must often be done at once, before one can send for a carpenter to come and do it. 3. An office is a very desirable thing about a trout- breeding establishment. It is almost as indispensable, in fact, as the carpenter's bench, unless your house is right on the spot. The office will be your comfortable room, where you can keep a fire, can transact business, make your microscopic examinations, examine the progress of ex- periments, take notes, do your writing, receive orders, and keep your record-books and show-case of speci- mens. Indeed, so many things call for such a room that no establishment is complete without it. 4. An ice-house is absolutely necessary, unless you can depend upon ice, whenever you want it, from out- side sources ; and even then it is desirable. In trans- porting live fish, young or old, you cannot do without ice, except in cold weather, and you may sometimes need it for the meat-house ; you will frequently need ice unexpectedly, and you must have it for shipping your large fish to market. Have an ice-house, then, by all 44 DOMESTICATED TROUT. means, and locate it near the hatching house, and wfcere the fish are packed for market. A building of the size of an ordinary family ice-house will do. 5. Besides these rooms, there are at the Cold Spring Trout Ponds a bird-pen, made of plank, large and dur- able, and a fox-pen, also built of wood and of good size. The bottom of the latter, made of plank, is laid three feet under ground, and is covered with earth to this depth, so that the animals confined may have a good place to burrow in, without being able to escape by burrowing. These pens are desirable, because as you will trap more or less about your place, you will sometimes catch ani- mals and large birds alive, which you may like to keep alive. There is also a roughly built shanty, with a stove in it, near the spawning beds, in which the spawn can be taken in stormy weather, which is also recom- mended. THE HATCHING HOUSE. The hatching house, or hatching room, is, of course, the central point of the whole establishment. Here the swarms of young trout upon which the other departments depend for their supply are brought into being; the greatest care, therefore, should be exercised in having it just right. It should in general be roomy, well lighted, firm, and durable. Such a one, however roughly made, will answer its purpose of hatching as well as a more ex- pensive one ; though if one's means are unrestricted, there is no reason why it should not be a handsome building, and an ornament to the place, like that of Colonel Thompson at Springfield, for instance. BUILDINGS. 45 The size of the hatching house depends on the amount of work to be done in it. A room thirty feet long and eighteen feet wide will have hatching space for one hundred thousand eggs, besides passage-ways between the troughs, or hatching-stands, and con- siderable spare room to keep the gravel-boxes, and to work in. For more eggs you will of course need more room ; but, whatever the amount of business you do, it should be remembered that it is far better to have too much room than too little. I know of few things more dis- agreeable than a cramped hatching house.* The hatching house should be located near the spring or reservoir which supplies it with water ; for the longer the aqueduct which takes the water from the spring to the house, the greater is the risk of the water going wrong. The house should also be placed, if possible, so that the water will enter it several feet above the floor. This will enable the hatching appa- ratus to be elevated to a convenient height for examin- ing the eggs standing or sitting, which is a great ad- vantage ; and I think it is better, on the whole, to incur the risk of a longer aqueduct from the spring, if neces- sary, to obtain this advantage. No fire is required in the hatching room, to keep the water warm.t That keeps warm of itself, and also keeps * Our hatching-house at the Mirimichi Salmon Breeding Works is a hundred feet long. t It is an addition to one's personal comfort to have a stove in the hatching house, though it may not be required to warm the water. 46 DOMESTICATED TROUT. the house comparatively warm. There is often a differ- ence of 30° between the outside air and the interior of the hatching room in extremely cold weather. It is a good plan to build the walls thick, and then the water running through will keep the air not very many degrees from its own temperature. This makes a much more comfortable room to work in. The shape of the hatching house will be determined almost wholly by local considerations. It is becoming quite the custom now to admit the light into the hatching room by large movable sky- lights in the roof; this is optional, however, unless sufficient light cannot be obtained otherwise. I will only add that if the four rooms mentioned — the office, storeroom, meat-room, and hatching room — are included in one building, the first three should be separated from the hatching room by a partition pre- pared with waterproof cement, or other covering, impervious to water. CHAPTER IV. HATCHING APPARATUS. hatching apparatus consists of the supply X reservoir, the aqueducts, the filtering arrange- ments, the distributing spout, and the troughs, or hatching apparatus proper. THE SUPPLY RESERVOIR. The supply reservoir, which hatches the eggs, is the great motive power of the whole establishment. It is this which does the work of replenishing all the other departments of the trout farm. On its steady, unfailing supply everything depends. If it should fail from any cause during the hatching season, the whole year's increase would be lost. It follows, then, from the importance of this agency, that it should be most securely guarded. You should, therefore, in enclosing the reservoir, make your work very firm and secure, especially the lowest parts of it, where there is the most danger. Leave nothing to chance in this work. Take no risk whatever, but guard it from the possibility of breaking away ; and in doing so, do not forget that muskrats and frost will have no more consideration for your hatching reservoir — so important to you — than for any other body of water. 48 DOMESTICATED TROUT. Make it as small as you can without sacrificing water. Cover it from dirt, leaves, and light. Keep it perfectly clean, and never put any fish into it under any temptation ; and finally, unless you are certain that you can make a very sure thing of it yourself, employ an experienced man to construct it for you. HATCHTNG-ROOM AQUEDUCT. One of the most important parts of the whole hatch- ing apparatus is the aqueduct which takes the water from the hatching reservoir to the hatching room. It may be nothing but a simple short pipe or spout, but its office is nevertheless exceedingly responsible. In- deed, it is literally a sine qua non of a hatching establishment to have this aqueduct safe ; for if it fails for a night to fulfil its purpose during the period of incubation, that is the end of that season's opera- tions, and unless you buy more eggs, there will be a gap of one year in your chain of fish broods that never will be filled up. This aqueduct, therefore, ought to be made espe- cially secure. To make it so, i. Build it of ij-inch or 2-inch plank, and fasten it firmly so that frost cannot heave it, and. so that it cannot be dis- placed by any accident whatever. I have known serious loss to result from an aqueduct being simply pushed out of place by the foot. 2. Char the plank. This I consider very important indeed, if you use plank, for you cannot be certain, without charring it, that fungus is not being generated in it. Do not imagine that you are safe from fungus HATCHING APPARATUS. 49 because your hatching boxes themselves are well guarded from it. It may grow in the aqueduct and be borne down by the stream, and before winter is over, you may find, to your dismay, that it has fastened its fatal grasp on your eggs. If so, they are ruined. There is no remedy for fungus which will make healthy fish of the eggs attacked. They may hatch, but the young fish will be good for nothing to raise. Therefore begin at the beginning, and guard your eggs from fungus by charring the aqueduct. 3. As a rule, it is best to have the aqueduct covered, but beware of making the outlet end smaller than the inlet end, for then, if anything gets into the pipe too large to pass through the outlet, it will stop the water, and your eggs will be ruined. I have known great danger and actual loss to come from such a defective aqueduct. In one instance a frog got into the pipe, in another a muskrat, in another a cork ; each of which came very near shutting off the water altogether and doing very great mischief. For further safety, put a coarse, galvanized-iron screen over the end of the aqueduct which receives the water. 4. If you have a small stream, and must convey it a considerable distance, and want to economize any- thing in temperature, you can keep it a little warmer by boxing up the aqueduct itself. But as a general thing it is labor wasted. You will be astonished to see how little any considerable stream changes in temperature in passing through even a long closed spout. At the writer's works at Charlestown, N. H., when 5O DOMESTICATED TROUT. the mercury is 10° below zero, the water at the hatch- ing house loses only two degrees in passing through one hundred and twenty feet of channel. THE FILTERING ARRANGEMENTS. Next to fungus, sediment is the most dangerous enemy to trout eggs, and, like fungus, it is the more to be dreaded because it is invisible ; that is, as it is held naturally in the water. A stream or a spring may look to you as clear as crystal, you may examine most carefully and not find any traces of dust or foreign matter in it, yet the same water in running sixty days over any given spot will very likely deposit enough sediment to kill a million eggs. Some few springs are, I believe, sufficiently free from sediment to be used without filtering, but such springs are exceedingly rare, and are the exceptions. As a rule, all springs and streams, however clear they may appear, will in time deposit a fine layer of dust, or sediment, as it is usually called, which is sufficient to destroy or de- form all the fish embryos that are exposed to it. It is very important, therefore, to have this sediment kept away from the eggs ; and to effect this, the water is conveyed through a very efficient filtering apparatus. This usually consists of a large tank containing a series of flannel screens. These screens consist sim- ply of light wooden frames, with flannel fastened on them, which are made to slide in grooves prepared for the purpose, on the inside of the tank. The flannel should be drawn tight over the frames, and the frames themselves should slide obliquely into HATCHING APPARATUS. the tank at a very considerable angle, say 45°, with the lower end up stream. a Flannel filters. b Hatching-room aqueduct or inlet. c Outlet. The tank should be built very solid, of two-inch plank, charred, and should be bound with iron bands, to prevent spreading. Its size will be governed, of course, by the amount of filtering required, a small or very clean stream needing less than a large or com- paratively turbid one. But be sure of one thing, that the tank is large enough, no matter how large that may be, to arrest all the sediment, beyond all possi- bility of risk. Thousands of eggs have been lost by the filtering tank being inadequate. Better have it twice as large as is necessary, than to incur any risk of not stopping the sediment. At the Cold Spring Trout Ponds there are two tanks for filtering, one containing eighty-one gallons and six filters, the other one hundred and sixty-eight gallons* and seven filters. 52 DOMESTICATED TROUT. I think it is better to have two medium-sized tanks than to have one excessively large one. I should call the first of the two just mentioned a medium-sized one, and the second a large one, as large, perhaps, as should be made. The outlet of the filtering tank should be at least six inches lower than the top of the tank, to guard against the water escaping over the top when the screens clog up. There should be two holes at least an inch in diameter in the bottom of the tank, to let the water off when necessary, and they should be plugged with very long stoppers, which will come nearly to the surface, so that they can be withdrawn without the arm being much immersed in the water. The filters themselves may be made of any kind of strong, coarse flannel. White has the advantage of showing dirt best, and red, Seth Green says, will last the longest ; otherwise, one color will do as well as another. These filters must be watched, and, no matter how often they require it, they must be taken out and cleaned as soon as they are dirty; but in doing this the rear one should be moved as little as possible. If you clean while wet, wash them under water, either with a brush, or a long-handled stick smoothed at the end ; the brush is the quickest method, the stick wears them out less. If you have a chance to dry them, the deposit on them can be easily brushed off with a dry brush. It may be necessary to clean the fil- ters every day. If it is, do not neglect it. The tank is placed, of course, at the outlet of the spring aqueduct, which is usually at the head of the hatching-room, and HATCHING APPARATUS. 53 no water should be allowed to pass over the eggs any length of time, without having first run through this tank. The tank rieed not be covered. THE DISTRIBUTING SPOUT. The next thing in order is the distributing spout, the office of which is simply to receive the water from the filtering tank, and distribute it into the various hatching troughs. It joins the filtering tank, and extends, of course, either way, as far as the hatching troughs reach later- ally, over which it is placed. It is provided with an outlet at the head of each trough, and it will be found a convenience to have all these outlets levelled so as to each draw an equal supply of water when they are open. To secure this, the openings farthest from the inlet screen should be a little lower than the next, and so on, for the water at the inlet will be a little higher than the other end. If built of wood, the distributing spout should be of i^-inch plank, charred, and should be abundantly ample in width and depth for its purpose. There should also be an aqueduct connecting the water supply above the filtering tank with the dis- tributing spout, so that the water can be temporarily turned directly into the distributing spout when it becomes necessary to wash the tanks. The distributing spout often has gravel placed in it for an additional filter. This is a good plan, because the gravel gathers up whatever fine sediment may have run the gantlet of the flannel filters, and any 54 DOMESTICATED TROUT. fine fibre of the flannel itself, which has become de- tached from the screens. But it is a better plan to have a special spout or aqueduct for the gravel filter, be- tween the filtering tank and the distributing spout, and to have the latter free from gravel, on account of the gravel in it being often an inconvenience. The gravel should be coarse enough to let the water pass through it freely, the pieces being of the average size of chest- nuts, or larger. There is usually enough of this coarse gravel sifted out when the fine gravel is being pre- pared for the hatching troughs. If fine gravel is used, it will force the water to flow over it, and thus defeat its purpose. HATCHING TROUGHS, OR HATCHING APPARATUS. The hatching apparatus is of course the central fea- ture of your whole indoor establishment, the part for which, indeed, all the rest is created. This is the foun- tain-head, from which all the other departments of the fish farm are furnished with stock. Here you intrust, for six months, the whole of your year's increase, and it occupies so responsible a place that no pains should be spared to get it right. Indeed, you cannot overrate the importance of having your hatching apparatus without a fault, especially as a single defect or neglect may cost you your whole stock of young fishes, — not merely part, but perhaps the whole. MATERIALS. Various kinds of material have been used for hatch- ing trout eggs, the principal of which are wood, soap- HATCHING APPARATUS. 55 stone, slate, pottery, metal, wood with glass lining, glass grilles, and charcoal, or carbonized wood. I think ex- perience will finally reduce the number in general prac- tice to two, namely, glass grilles and carbonized wood. Wood in its natural state is out of the question, for the fungus that it grows wholly unfits it for hatching. I venture to say that hundreds of thousands of eggs have been destroyed by the fungus coming from wood- en troughs. Metal, whether in the form of screens or anything else, will not do, because the absorbing power of trout eggs is so great, that, if placed in con- tact with it, they will in time absorb enough metallic matter to destroy them.* Slate, pottery, and soapstone answer very well, but are all expensive; and if an expensive article is used, glass grilles, I think, have the preference over everything else. For cleanliness, tidiness, and convenience they are not surpassed by anything. Their expense is their only objection. Charcoal troughs, on the other hand, are equally as effective as grilles, and infinitely more economical. They are also more accessible, more simple, and more durable. In estimating their comparative merits I should say that the glass grilles are the thing for the rich man's experiments, and the carbonized troughs are the thing for business ; I cannot but think that the carbonized troughs will supersede everything else, where trout- * Fourteen trout eggs were placed on a copper-wire screen, in November, 1869, at the Cold Spring Trout Ponds, and in fifty days they had absorbed so much copper that they were of a dark brown tinge, and hard like peas. 56 DOMESTICATED TROUT. breeding is carried on on a large scale, or where dura- bility, economy, or accessibility must be consulted.* The comparative expense of the two methods may be estimated as follows : Glass grilles cost per tray $ 3.50 each, by the quantity.! Allowing 1,250 eggs to each tray,f the apparatus for hatching 100,000 eggs, with glass grilles, costs $ 280. The expense of the patent carbonized troughs, includ- ing cost of right to use them, is less than forty cents a foot, for one hundred square feet. Allowing 1,000 eggs to the square foot, the apparatus for hatching 100,000 eggs, with the carbonized troughs, costs $40, leaving a balance of $ 240 in favor of the carbonized troughs. Besides this, in the country, where most of our trout ponds are and will be, the wood to make the troughs, and also wood to char them with, is always plenti- ful and within reach, and, once prepared and placed, the carbonized troughs will last no one can tell how long. The perfect freedom of charcoal from fungus, and its tendency to purify the water, will, I feel confi- dent, make it a favorite for hatching all eggs that are to be long under water. The carbonized troughs were first experimented with at the writer's salmon-breed- ing establishment on the Mirimichi River, where they worked to perfection. They have since been used at the Cold Spring Trout Ponds, and have given the most complete satisfaction. J * See Appendix IV., p. 306. f See Dr. Slack's Catalogue, p. 4. t The use of charcoal or carbonized wood for hatching fish was patented by the writer, June 20, 1871. HATCHING APPARATUS. 57 They seem to have solved the problem of obtaining a safe, economical, and durable material for hatching trout. I am aware that some of our largest operators have used wood loosely lined with glass, but it costs a good deal to get the glass, and it is also extremely un- safe when the young fry hatch, for they will get under the glass by thousands, and die of suffocation ; and finally it does not answer perfectly, as charcoal does, the purpose for which it is used, namely, to obviate the growth of fungus. I would recommend, therefore, the use of glass grilles if you have the means and think they are better. Use charcoal or charred wood if you do not use grilles. PLACING THE HATCHING TROUGHS. Having decided on the material for the hatching boxes, the next thing is to construct and place them. If you use charcoal or carbonized troughs, you should first send to the Cold Spring Trout Ponds, at Charles- town, N. H., and obtain the right to use them, they being patented, and the directions how to prepare them. As to the size and shape of the hatching boxes or troughs, a great variety of opinion prevails. The fol- lowing suggestions, however, may serve as a guide in making a selection. If you are limited in your supply of water, you should use long and rather narrow troughs, say twenty feet long by eight inches wide, and if you wish, you can have another trough of the same size be- low the first tier, using the same water over again, pro- vided you have a fall between the two troughs of six 58 DOMESTICATED TROUT. or eight inches. This second lower tier of boxes is, however, somewhat objectionable, because whenever the screens of the upper boxes are cleaned, or the water in them for any reason disturbed, the lower ones, in taking the washings from the upper, must suffer. This can be obviated, it is true, by cutting off the water temporarily, but this, again, is not only dangerous, but often inconvenient. It is best, therefore, not to use the water but once in hatching, if you have enough. Still it can be used twice, if necessary, without great injury. If you have plenty of water, I would recommend shorter troughs and more of them. There is no harm in hav- ing them twelve inches wide. I prefer ten or eight inches, however. They should be at least six inches in height in the inside, to guard against their running over, from the screens clogging up, and it is desirable to have them still higher, say eight inches, if you mean to keep the young fry in them any considerable time after they hatch. The troughs should be divided into compartments about one inch deep and fifteen inches long, by nailing charred cleats of the required depth transversely on the bottom of the trough, at regular intervals of fifteen inches. The head of the trough should be placed just under the distribut- ing spout, from which there should be a fall of a few inches ; the trough should be high enough from the floor, if practicable, to be examined by a person stand- ing. The troughs should be inclined, so that the water will make a gentle ripple over the cleats. A grade having a fall of one and one fourth inches to ten feet will do very well, but be sure to have enough slope to HATCHING APPARATUS. 59 make the ripple, otherwise your fish, when hatched, will not be as strong as they might have been. At the lower end of the trough there should be a copper-wire screen of about eighteen or twenty threads to the inch. This screen should be very carefully fitted in, and should be made as tight a fit as human handiwork can make it, otherwise you cannot be sure that the young fry, when first hatched, will not slip through. In order to be perfectly sure to get this screen safe, first exam- ine the place or bed that it fits into, with a strong light, and take care that every bit of sand or gravel is re- moved from it. Then put down the screen, having previously arranged a perfectly tight fit in the side cleats, and hammer it down. This done, sift sand along the bottom and sides of the screen, bank up with gravel to the height of the transverse cleats, and sift sand about the sides again. You are then as safe as you can be with regard to the screen, and with these precautions you will be pretty sure not to lose many fish by this most common of all avenues of escape, — loosely fitting screens. Should any aperture be caused in the future by any spring- ing or shrinking of the wood, or otherwise, calk the opening with flannel without delay. Below this screen should be placed what is called a trap-box, to catch any of the young fry that may escape through the screen above. This trap-box is nothing but a com- mon box with a wire screen, which will let out the water, but hold the fish that come into it. I would have one at the end of every hatching trough. They are a very important safeguard, for they not only save 6O DOMESTICATED TROUT. all the fish that come through the screen, but will al- ways tell you whether any are escaping, and also whether the screens are tight. If you do not provide this safeguard, thousands of fish may escape before you know it. It is a good plan also to have a larger box or reservoir, still farther down, on a similar plan, collecting the water from all the troughs, and arranged so as to detain everything that may have escaped, from any cause, from above ; and I think I may safely say that you will be astonished to find how often the young fry slip past places that you have considered perfectly tight. Having so far prepared the hatching troughs for action, and having tried them by running a stream of water through them, the next thing is LAYING THE GRAVEL. Gravel is used to hatch the eggs upon. This hatching gravel should be the size of half a pea, or less. Coarser gravel will not do, because the eggs will get into the chinks between the stones, and, being out of sight, will die without your knowledge; and when they die, the dead eggs will certainly grow the fatal byssus, which will stretch its long arms out over other eggs above or near it, and destroy them. Coarse gravel is very vexatious on this account. Any clean gravel of the right size, free from rust, rotten stone, and the like, will do, and you will frequently find such gravel nearer than you suppose. It is therefore a good plan to try any high banks near by, before sending a great way for it. You may often find just what you want in a bank right over your HATCHING APPARATUS. 6 1 brook. To prepare the gravel for use, you should have two screens, one to sift out the sand, and another to hold the coarse gravel. The residue which remains in the first and goes through the second screen is what you want for the hatching troughs. Having obtained the right size of gravel, the next thing is to wash it. This should be thoroughly done. Then you can boil it, if you wish, to kill the insect larvae in it ; and I would advise you to do this by all means, for the larvae in unboiled gravel often produce insects that are very destructive to the eggs and young fish. It is not absolutely necessary to use gravel in charcoal troughs, as the eggs will hatch safely on the charcoal bottom. Twenty thousand salmon-eggs were placed directly on the bottom of the charred troughs, at the writer's establishment on the Mirimichi River, by way of experiment, and they did as well as the others hatched on gravel. A thin layer of gravel, however, is recommended. The gravel, if used, should be evenly placed in the troughs to the depth of about half an inch. According to the old method of hatching on wood in its natural condition, the gravel was placed an inch and a half deep, to prevent the fungus from growing up through it ; but in charcoal troughs, where there is no fungus, half an inch in depth, and even less, is sufficient. Be careful to level it off evenly, and leave no holes or depressions, or the eggs will surely collect in them deeper than they ought to. There is always so much use for gravel about trout- breeding works, that it is a good plan to save all kinds, and what has been used once, and not washed, put 62 DOMESTICATED TROUT. away by itself. It is therefore a good plan to have four barrels or large boxes in the hatching house, — one for coarse gravel not clean, and one for fine gravel not clean, one for clean coarse gravel, and one for clean fine gravel. These boxes should be distinctly labelled, so that clean and dirty gravel will not get mixed ; and in course of time this little systematizing of the gravel will be found to be a source of great convenience, and economy also. A bushel of prepared gravel usually costs more than a bushel of grain. When the gravel is laid in the troughs and the water is turned on, they are ready for use, with one exception, viz., — THE COVERS. I am firmly convinced that hatching troughs should be covered. I would not have one without a cover. Trout eggs and salmon fry are stronger and healthier for being hatched in the dark. It is more natural also. The foetus, or embryo, of almost every creature — beast, bird, or fish, everything above insect life — is developed in the dark. The embryo of the trout is no exception to the rule. After the parent trout has deposited its eggs in the bed of the brook, the gravel with which they are covered, the stratum of water above the gravel, and the layer of ice and snow above the water, make it as dark, where the eggs are, as it is in the covered hatching-troughs. Furthermore, the light seems to have a forcing effect on the eggs ; and those that I have seen matured in the light did not contain the dark, thick, firm, HATCHING APPARATUS. 63 vigorous-looking embryos that are sure to develop in the dark. At all events, my experience has been decidedly to the effect that eggs hatched in the dark develop a thicker, firmer, and harder fish than those hatched in the light; and the first three months of feeding proves it. I am sure, at least, that no young trout fry could be hardier or healthier than mine have been through their first six months, and all of mine are hatched in coveted hatching troughs. But even if darkness were not desirable, there is another reason of the utmost importance for having covers on the troughs. It is that you are not certain that your eggs are safe a single night in the open troughs. The enemies of trout eggs are legion. Mice, snakes, lizards, rats, weasels, and you know not what else, may be feeding on the eggs every night if they are not covered. I lost thousands of eggs and alevin trout in this way, before I began to use covers. At the Mirimichi Works, we lost at least twenty thou- sand salmon eggs, in the course of two weeks, by a weasel, before we began to suspect danger. There is no security without covers, at least in ordinary hatching- houses. On the contrary, when the covers are on and down tight, then, and only then, you know you are safe. And this is the only normal condition that any department of a trout-breeding establishment should ever be in. The covers, for convenience' sake, should be made as light as possible. Half-inch pine, and even thinner, answers very well. There should be a piece cut out at the upper end to let in the water, and wire netting 64 DOMESTICATED TROUT. should be tacked over this opening, so that there can be no danger of anything getting in there ; and if the covers do not fit down tight, they should be hooked down, or caught with a spring. When the carpenter puts on the covers, examine them carefully, and see that there are no chinks to admit even a lizard. If there are not, then your hatching boxes are complete in every respect, and, if the previous suggestions have been carried out, will do their work to your perfect satisfaction. USE OF GLASS GRILLES. I have proceeded thus far on the supposition that troughs of carbonized wood or other material are used. For the guidance of those who prefer glass grilles I quote the following remarks upon them from "Harper's Magazine"* and from Dr. Slack's Cata- logue of fish culturist's apparatus. " The Coste Hatching Tray (glass grilles) consists of a trough (made of earthen-ware, glass, or slate) about two feet long, six inches wide, and four inches deep. On the inside, about two and a half inches from the bottom, are small projections, upon which rests a glass grille, a species of gridiron formed of glass tubes placed closely together, the ends being confined in a wooden rack. There is a spout on one side and at the top of the box to run off the surplus water ; at the bottom and below the level of the grille are two other openings, usually stopped, but con- venient to open in order to remove the sediment which from time to time collects. In using these hatching boxes, water can be supplied from a water-cooler through a filter, * Harper's Magazine, November, 1868, pp. 728, 729. HATCHING APPARARUS. 65 and after passing through the box it can be caught and used over again. If water has been laid in the house, a constant stream of fresh water can be kept flowing with less trouble by using a discharge-pipe instead of a receiver. In one such box a thousand eggs — the product of a single trout — may be hatched. It will require no more attention than a globe of gold-fish, far less than an aquarium, afford a far more interesting study than either, and be quite as much of a parlor ornament. " If it is desired to experiment more largely, this box may be duplicated interminably, as has been done by Mr. Coste, in perfecting his apparatus in use at Huningue. No greater supply of water and very little more room is neces- sary for a dozen than for one box on this plan. The ad- vantages of this apparatus are : First, cleanliness, the sedi- ment being easily removed without disturbing the eggs ; secondly, the eggs can at all times be readily examined ; and thirdly, the fry or young fishes can be removed from one box to another with facility, thus leaving room for more eggs in the first boxes. " These trays, invented by M. Coste, Professor of Em- bryology in the College of France, have been used during the past season at my ponds with perfect success, and it is intended in future to hatch all our spawn in them. The boxes are made of the best galvanized sheet-iron, and are coated inside and out with asphalt varnish. The grille is composed of strong glass tubes, firmly fastened in a frame of black walnut. This is so arranged that should any of the tubes become broken they can be readily removed and others substituted. Each box will hatch from one thousand to fifteen hundred eggs. "Prices of Coste Hatching Trays. " Single trays $4.00 One dozen trays 45.00 66 DOMESTICATED TROUT. Fifty or over, at the rate of . . . . $3.50 Extra glass tubes (each) .05 " " " per pound 75 "FLIGHT OF TRAYS WITH STAND. " This is a neat and convenient form when several trays are required. " The stands are made of the best seasoned white-pine, neatly framed together. "Prices* " Flight of five trays and stand .... $21.00 " three " "... 13.50 Stands for five trays 2.50 three " 2.00."* There is another form of grilles used, which has stood the test of experience very well. It consists of very narrow strips of window-glass, laid side by side in the hatching box, an inch or two from the bottom, and closely enough to keep the eggs from falling between them, but wide enough apart to allow the hatched fish to fall through. Each alternate strip is placed about an eighth of an inch lower than the rest. In this depression the eggs lie until hatched, when the young fish fall into the box or trough below. The advantage of this class of grilles over the last form is that they are cheaper. Another advantage is that they can be used in water where too much sediment would collect on tight grilles or in troughs, the sediment being easily washed off the eggs on the * Dr. Slack's Catalogue of fishes, and apparatus used in fish culture, pp. 4, 5. HATCHING APPARATUS. 6/ strips, and sinking down through the apertures out of the way. WIRE-NETTING HATCHING TRAYS. When the foregoing part of this chapter was writ- ten in 1872, wire trays were not used to much extent for hatching the eggs of fish. At the present writing, in 1877, wire trays are very extensively employed, and it seems likely that their use will entirely supersede the old method of hatching on the bottom of the hatching troughs and on glass grilles. The trays in question consist simply of a light wooden frame made perhaps of three-fourths inch stuff, with a wire-netting bottom, or, in the case of deep trays, wire-netting sides also. The trays are made a little narrower than the troughs, and of any convenient length, from a foot to eighteen inches, or two feet. They are coated all over twice with asphaltum varnish, to keep the wood part from grow- ing fungus and the iron part from rusting. They are usually placed on a rack, to raise them an inch or two from the bottom, and the whole bot- tom of the trough covered with them, the end of one adjoining the end of the next, and so on. If desir- able, another tier can be similarly placed on top of these, and another, and another; as many tiers being laid as the water supply and circulation will warrant. They can be used in various other ways, as will be seen further on. The advantages of the tray system are very great, the chief merits about it being that it economizes 68 DOMESTICATED TROUT. space, makes the handling of the eggs simpler and easier, and provides an easy way of getting rid of sediment. These points will .appear as each particu- lar method now in use is taken up in turn. VARIOUS METHODS OF USING HATCHING TRAYS. There may be other ways of employing wire trays for hatching purposes, but those which have come particularly under my observation are six in number, and may be enumerated as follows : — (i) The one-tier method ; (2) the double-tier meth- od ; (3) the Williamson method ; (4) Clark's method ; (5) Holton's method ; (6) the use of deep trays with the Williamson hatching troughs. 1. The one-tier method consists simply in covering the bottom of the common hatching troughs with shallow trays raised about half an inch from the bot- tom, to allow the water to flow under as well as above the eggs, and also to give the sediment that collects a place to settle in, out of the way of the eggs. The water is turned through the trough as usual, and there is nothing else peculiar about the use of the trays be- sides what has just been mentioned. If there is much sediment in the water, this method is a vast improve- ment over the old one of placing the eggs on the bot- tom of the troughs ; for while there is a space under- neath the trays for the sediment to settle in, it can always be kept off the eggs. This plan is usually adopted in trout-hatching establishments where the sediment is very troublesome. It is not patented. 2. The double-tier system consists in placing one HATCHING APPARATUS. 69 tier of trays above another in the hatching troughs. If there is abundance of water, three or four tiers can be safely used. More than this with the ordinary hatching troughs would be inconvenient, as the lower tier would necessarily be so deep in the water. The advantage of this system is that it economizes room, it being obvious that with four sets of trays running the whole length of the trough, one above another, four times as many eggs can be hatched in a trough as could be hatched in one set of trays. This plan has been in use, I think, at the United States Salmon-breeding Es- tablishment in Maine, under the charge of Mr. Charles G. Atkins. It is not pat- ented. 3. Williamson's Method. — This is really a modification of the hatching trough, but as it is intended only to be used with trays, and as it makes an entire change in the tray system, I include it here with the other methods of employing trays. Ac- cording to this plan, the water is forced up through these trays from the bot- tom. This is accomplished, as will be seen in the accompanying diagram, by placing at the lower end of each compartment in the troughs a cleat extending entirely across the trough, and reaching from the bottom almost to the top, and by placing at the upper end a similar cleat reaching 7 " to sit on," has been used in reference to the hatching of bird's eggs by steam, and seems to be equally allowable in this application for the hatching of fish eggs. There is no sitting upon the eggs in either case. 138 DOMESTICATED TROUT. At the end of a few hours, more or less, according to the temperature of the water, the germ of the egg rises to the top in both the fertilized and the unfertilized egg, which look exactly alike. The germ in the un- fertilized egg, however, undergoes no change whatever from this time, while in the fertilized egg a process soon begins which is called by the French embryologists " sillonnement? or furrowing, and by English writers " segmentation." This process begins by the sinking of a deep furrow through the centre of the germ, divid- ing it into two equal parts. This is followed by an- other, bisecting the first, and another and another, until the subdivisions have been continued indefinitely, when the germ again presents nearly the same appearance as at first. While this " sillonnement? or segmenta- tion, is going on, the original disk formed by the germ in the impregnated egg disappears, and cannot be seen at all, thus distinguishing it plainly from the un- impregnated egg, which still presents the germ disk as clearly as ever. Therefore at this period the unim- pregnated eggs can be told from the impregnated ones by the one presenting the distinct germ disk, while the other shows no trace of it. The percentage of impregnated eggs can now be told approximately ; but as the light must be favorable in order to tell which eggs have the germ disk visible and which have not, and as it is not a good plan to handle the eggs too much at this stage, it is perhaps quite as well to be patient and wait till the tissues of the fish are firm enough to allow the egg to be han- dled, and the clearly marked eye-spots leave no doubt HATCHING THE EGGS. 139 as to which eggs are impregnated and which are not, before attempting to decide with much exactness on the percentage of impregnation. As remarked above, a fine dark line near the mid- dle of the impregnated egg will be observed, on close examination, about the end of the first third of the hatching period. Soon the whole form of the fish will become cloudily apparent, and then the black eye- spots will appear, first one and then both. Now is the best time to tell what proportion of the eggs are im- pregnated. You can form some estimate, perhaps, be- fore, by taking out a few in the phial, say ten, and counting the impregnated ones in it. If, for instance, nine are visible, then you infer that ninety per cent are good. But this method is very deceptive, and can- not be relied upon, both because the number is too small to base an estimate on, and also because the specific gravity of the empty ones being a little less than that of the full ones, it sometimes happens that a twirl of the feather will throw the empty ones together in a hole, and the impregnated ones together in another pile, on the mechanical principle which leaves sand, marl, and vegetable matter in a brook in different spots by themselves. In taking out three or four in a phial for examination, you may happen to hit upon one of these piles or the other, and so get a deceptive sample of the eggs in general. The best way to get the ratio of the good to the worthless ones is to take out several hundreds or a thousand after the eye-spots show plainly, and pick out the empty ones. Count both, and add its proper- I4O DOMESTICATED TROUT. tion of previously removed eggs to the number of empty ones, and you get at the proportion of impreg- nated eggs. This, however, only answers for the par- ticular box from which these were taken. To obtain the percentage of the whole season's yield, this opera- tion must be repeated with each box or compartment. It will be well to observe here, also, that it is a good plan, as soon as the impregnated eggs are unmistaka- bly distinguishable from the empty ones, to take them all out into pans, and remove all the empty ones before replacing them in the hatching-boxes. The work of picking over will be done much easier and quicker this way, and it has this great advantage, that it is done once for all, and you are for the rest of the season relieved of the burden of care which the daily necessity of removing the empty ones in- volves. The time required for hatching depends chiefly on the temperature of the water. Seth Green's rule is that at 50° Fahrenheit trout eggs will hatch out in fifty days, and every degree warmer or colder makes five days' difference in time ; warmer water shortening the period, and colder water lengthening it. Green also says, that if the fish are hatched in fifty days, the yolk sac remains thirty more. If in seventy days, the sac remains forty-five days. HATCHING THE EGGS. 14! Mr. Stephen H. Ainsworth's table is as follows : — Average tem- perature of water. No. of days to first formation of trout. No. of days to formation of eyes and red blood. No. of days to hatching. No. of days after hatching to feeding. o 37 43 81 I65 3§i 2Q 64 135 77 39 2o 62 121 4oi 27 54 109 60 4i 21 49 103 42j 19 42 96 43* 17 37 89 46 44 16 34 81 45£ 15 31 73 4&i 48 13 II 29 26 3 50 10 23 47 30 52 8 18 38 54 7 15 3- Appearance as fig. 7. as fig. 12. of spawn as %• 3- Although results somewhat varying from these fig- ures will be obtained in different waters, they may, nevertheless, be regarded as a safe guide in general. I will only add that in my own experience I have found that the yolk sac requires more time for its absorption in proportion to the time of incubation ; I should say quite a third more. As the development of the embryo advances, the care of the eggs will become more and more inter- esting. They will, however, lose their bright crys- talline look, as they lie in the water, and will assume, collectively, a dull brownish hue ; but when exam- ined separately, it will be seen that this does not 142 DOMESTICATED TROUT. arise from any unfavorable change, but from the embryo thickening and darkening in the shell. This development and the filling up of the shell with the embryo proceeds rapidly till about the same time has elapsed that was required for the eye-spots to appear, when the whole figure of the fish, thick and black and fully formed, will be seen, usually lying quiet and motionless, but occasionally stirring with a little spasmodic leap or wriggle. The time of their release is now near at hand, and you may expect to find a newly hatched trout or two in your earlier hatching boxes any day.* An inexperienced person might suppose that all trout eggs will produce fish that are just alike when hatched. But this is very far from the fact. There is just as much difference in a brood of newly hatched trout as there is between the brawniest and puniest of a litter of pigs or brood of chickens. Some will be large, strong, and full of vigor ; others will be small, weak, and inactive. It is a desirable thing to be able to know how to tell a lot of eggs that will produce good fish from a lot that will produce poor fish, and it is very easy to learn. If the embryo in the egg is seen to be dark, firm, thick, clearly defined, * As you will probably want to procure specimens of eggs and fish at different stages of growth, it is a good plan to have a set of homoepathic phials in readiness, and some alcohol. One part alcohol to three parts water is a good preserving mixture at this stage. This* mixture will congeal, but will not expand in congealing sufficiently to burst the bottles. More alcohol with the water will destroy the delicate tissue of the embryo. HATCHING THE EGGS. 143 and heavy-looking, and hatches late, the egg will pro- duce a healthy, hardy, broad-shouldered trout, and a good feeder. If the embryo is seen to be thin, light, transparent, and hatches before its time, it will pro- duce a puny, weakly, thin-bodied fish, and a poor eater, which has not five chances in a hundred of grow- ing up. Do not be anxious to have your eggs hatch early. If they hatch before their time, it is a bad sign. If the embryo remains long in the shell after formingj and hatches late, it is a good sign. One sure con- sequence and indication of the presence of fungus is the premature hatching of the egg, before the embryo has become well hardened within the shell. Beware of eggs that promise to hatch too early, for they are very likely to be fungussy ; and out of a thousand fun- gussy eggs it is an even chance if one embryo lives a year. The microscopic changes in the eggs from day to day are presented in the accompanying drawings by Professor Agassiz. 144 DOMESTICATED TROUT. 125 HATCHING THE EGGS. 145 These plates represent eggs of the Coregonus palaa in differ- ent stages of their growth, as seen under a powerful magnifier. No. 15 represents a spoiled egg. No. 20. The embryo ten days old. No. 33. Front view of embryo eighteen days old. No. 99. An egg two days after impregnation. No. 101. Appearance of first furrow second day after impreg- nation. No. 1 02. An egg showing development of furrows. No. 107. Mulberry form of the embryo. No. 109. Embryonic germ immediately after the disappearance of the furrows. No. 125. Projection of the embryo prepared with acid, 8th day. No. 133. Projection of embryo prepared with acid, iyth day. The letters denote as follows : — a Shelly membrane ; b Yolk ; c Germinal vesicle ; d Yolk globules ; e Oil drops ; f Albumen ; g Yolk membrane ; k Yolk vesicle ; / Head of the em- bryo ; j Yolk cavity ; k Trunk of embryo ; / Tail ; m Dorsal keel ; n Dor- sal furrow ; o Ocular lobes ; / Dorsal cord ; q Vertebral divisions ; r Sheath of dorsal cord ; s Cephalic bow ; t Nuchal bow ; u Trunchal bow ; v Epider- moidal stratum ; x Procencephalon ; y Mesencephalon ; z Epencephalon. As too much caution cannot be observed in trout- culture, I hope the reader will pardon my repeating here the cautions already given : — To keep the covers down carefully ; To change the filters when dirty ; To take out every dead egg once in twenty-four hours ; To use the watering-pot freely, if sediment settles on the eggs ; To guard everywhere against fungus. TRANSPORTATION AND PACKING OF THE EGGS. Transportation of the eggs. No one need have any fear about being able to transport trout eggs safely. 146 DOMESTICATED TROUT. They have been sent to England and California with- out loss, and salmon eggs shipped from England have reached Australia alive. I have sent eggs to Kansas and Europe safely, and one hundred and seventy thou- sand salmon eggs from the writer's Salmon-Breeding Establishment on the Mirimichi came eight miles by private conveyance, one hundred miles by stage, one hundred miles by rail, two hundred miles by steamer, across the city of Boston by wagon, and one hundred and twenty more miles by rail before reaching their destination, where they were found, on opening, to be in good condition. Indeed, when trout and salmon eggs are carefully packed, they are about as safe in the moss which encloses them as they are in the hatching boxes, and the only risk to which they are exposed in transportation is rough handling ; and I have observed that they will stand a good deal of that. A few, say a dozen in a thousand, will perhaps die on the way ; but excepting these, they will, as a rule, arrive at their destination unhurt. Injury to any greater extent is the exception. On the tag or label which accompanies them should always be distinctly written, — That they are fish eggs ; That they should be handled carefully ; That they should be kept in a cool place ; That concussion will kill them ; That they must not be allowed to freeze. Packing the eggs. It is a sort of paradoxical fact that fish eggs do not require much water for hatching, but, relatively, plenty of air. Consequently, when HATCHING THE EGGS. 147 packed in wet moss, the conditions of hatching are supplied, namely, a little moisture and plenty of air. Moss is at the same time so soft that it will not bruise the eggs. Hence, wet moss is just the thing to pack fish eggs in. The moss containing the eggs can be packed in anything which admits air and is not injured by moisture. For packing in large quantities, a basket answers very well. Fish eggs have sometimes been sent in small quantities in a perforated percussion-cap box, and in tin snuff-boxes. If sent by express without an attendant, the basket or box containing them should be packed in a still larger basket or box, containing hay or shavings or sawdust, to soften the force of accidental concussions, and to keep the temperature of the eggs equable. The usual way in practice to pack the trout eggs for transportation, with small quantities, is that adopted by Seth Green, which is to pack them in circular tin boxes, not over three or four inches in depth,* with a * A circular tin box 6 inches in diameter and 4 inches deep is supposed to be able to hold about 5,000 eggs ; but the best way 148 DOMESTICATED TROUT. perforated bottom to let the air in, and to pack the boxes themselves in a tin pail, somewhat larger, and to fill in with sawdust This is a simple, com- pact, and safe way, and is the best now known, unless it is Mr. Wil- mot's method.* The packing of the eggs in moss should be done as follows : Fill a large pan, a little deeper than the packing-box, with water. Make a bed of moss about half an inch deep on the bottom of the box, and sink the box in the pan of water. The bottom layer should be a single bunch of some kind of the finer common mosses, which are found almost anywhere in the woods. The subsequent lay- ers should be the damp rank moss which grows in swamps, and is known by the name of Sphagnum. Then take the required number of eggs from the is not to have any rule about it. Make your tin boxes to match the size of the pails in which they are packed. * Mr Wilmot's method of packing fish eggs is a very excellent one. His apparatus consists of a cylindrical can of tin, say fifteen inches in diameter, having two walls or sides, one within the other, on the refrigerator principle. The annular space between the two walls is filled with sawdust, to preserve an even tempera- ture within. The cylindrical space enclosed by the inner wall is HATCHING THE EGGS. 149 hatching-troughs,* and pour one layer evenly over the moss.t This can be done with a spoon, or still better, perhaps, as Green suggests, with a ladle, the mouth of the ladle in pouring being made to rest on the rim of the box under water,J so that the eggs will not come to the air at all. One layer of eggs having been placed, put in anoth- er thin layer of moss. This layer, as also the others filled with shallow circular trays about an inch deep, all of the same size, resting one upon another, and of a sufficient diameter to fit nicely to the inner wall of the can. Each one of these shallow trays or pans has a circular hole through the centre to admit a movable iron rod, which runs from the top of the can to the bot- tom of the last pan, to which it is fastened. The eggs are packed in moss in the shallow pans, and each pan as it is packed is strung on to the perpendicular rod, as beads are strung on a string. The first one, of course, going to the bottom of the can, the next resting on it, and so on till the top of the can is reached. The upper end of the rod now serves as a handle, by which all or any number of the pans can be raised at once out of the can, and by unstringing the pans, so to speak, each one with its con- tents can be examined. * Any strainer of convenient shape will do to take out the eggs with. If they are much scattered, first collect them to- gether in a heap with the feather. A skilful person will take them out safely with a large table-spoon. t Theodore Lyman recommends placing each layer of eggs in a fold of mosquito-netting, to keep them from mixing with the moss, and so facilitate the unpacking of them. This is a great improvement. By all means use the mosquito netting. Stationary racks are also sometimes placed above each layer to catch the pressure of the supervening eggs and moss. \ All moving of eggs should be done under water when prac- ticable. DOMESTICATED TROUT. succeeding it, should be carefully picked over, and all grass and roots removed, so as to make as soft and delicate a packing as possible. After the second layer of moss, place another layer of eggs, and so on, alternating till the box is filled, taking care to keep the box and to conduct all the operations under water, for it should be always borne in mind, when fish eggs are moved, that the secret of moving them correctly is to keep the eggs in the water ; where, of course, they ought to be. After the top layer of moss is placed, take the box of moss and eggs out of the pan, and set it where the superfluous water will drip out through the perforated bottom. If the moss settles much with the escape of the water, fill up to the top again with moss. Then, when the cover is soldered on in one or two places, to prevent displacement, it is ready to be packed in the pail of sawdust, the cover to which should be kept in its place by being well wired down. When the label is fastened on, the eggs are ready to be sent off. CHAPTER III. CARE OF ALEVINS * OR TROUT FRY WITH THE YOLK SAC ATTACHED. SOME morning when you go to the hatching boxes with the nippers to look over the eggs, you will see a long, thin, dark object, like a little splinter of wood, lying among the eggs, which you will perhaps attempt to remove with the nippers, wondering how it came there in the night. The first touch of the nippers will show it to be a living creature, and you will experi- ence, if you are a beginner, the exquisite sensation of knowing that your first trout has hatched. Soon others will follow, only one or two to the thousand at first, then more, till the hatching period reaches its culmination, when the eggs will hatch in great quanti- ties daily, after which the number will decline again at very nearly an inverse ratio of progression. A warm rain will accelerate the hatching very much, as it does every other process of trout-life. More, per- * I am aware that this French word, " alevin," means young fry ; but as there is no distinctive English word to designate a fish during the period of the absorption of the yolk sac, and as the word has been employed by at least one English writer (Francis, Fish Culture, p. 99) in the present application, though not, I believe, by American writers, I take the liberty to use it in this treatise to distinguish the trout fry with the yolk sac attached. 152 DOMESTICATED TROUT. haps, will hatch in x>ne day, during a warm rain, than in the three subsequent days. The newly hatched fish are about half an inch in length. The yolk of the egg is still attached to them, from which they are nourished by absorption till it is all gone and they begin to feed. The period of ale- vin life is about two thirds or three fourths the length of the period of incubation. Its duration, like that of the egg period, depends on the temperature of the water, and it often happens, in water of a falling temperature, that the yolk-sac period lasts longer than it took the eggs to hatch. On the contrary, with eggs hatched late in the spring, as in the natural brooks, with a rising tempera- ture, the yolk sac remains on a very short period com- pared with the hatching of the eggs, — probably in some instances not one quarter of the time. During the period while the young fish are breaking the shell, the bottom of the troughs becomes quite un- clean from the collecting of cast-off shells and other causes, and it is a good plan to use the watering-pot freely at this time ; and as soon as' it can be done without injury to the young fish, the bed of the troughs should be covered over with a layer of fresh clean gravel. The alevins lie quite still the greater part of the time at first, sometimes on their sides, sometimes flat on the sac. Occasionally they vary the monotony of this quiet life by aimless sallies of a few inches through the water, apparently in great excitement, but with no particular goal in view. The exertion will soon bring them to CARE OF ALEVINS. 1 53 the ground again quite out of breath, with their little hearts beating very fast, as is not surprising, consider- ing their age, and that they carry about a burden twice the bulk of their bodies proper. They require no watching nor care of any kind for the first few days. They do not try to get away, they do not require to be fed, and if the hatching apparatus is well arranged, and throws a good supply of water over them, very few will die. Indeed, the yolk-sac period is one of the healthiest of the trout's early life. They seem at first to be possessed of no particular instincts, but lie still near the spot where they were born, and do nothing. This, however, lasts only a few days.* They are soon seized, sometimes very sud- * The following notes are taken from the writer's diary, Janu- ary, 1869. The embryos observed, were hatched from salmon eggs brought from the Mirimichi River. They were kept in a warm room, at a temperature that would probably make one day an equivalent of two or three days in the hatching trough at 45°. First day. Eggs hatched to-day. Young fish quite vigorous. Yolk sac plump and full. Body proper, thin, and delicate, and with cloudy outline. Second day. Change very slight. Outline a little more distinct. Body darker. Sac not quite so plump. Third day. Changes of yesterday slightly intensified. Beating of the heart very perceptible. Main artery distinctly seen. Foiirth day. Form of yolk sac decidedly changed. Body firm- er and darker. Eyes very clear. Motion of fins quite per- ceptible. Fifth day. Fish much livelier. A new movement of the tail observed. Sixth day. Yolk sac very considerably changed, and contract- ing towards a point at the lower end. Other blood passages clearly perceptible. 154 DOMESTICATED TROUT. denly, with a singular and irresistible instinct to hide under something. If they do not find anything in the troughs to get beneath, they all try to hide under each other. From this moment they are never at rest day nor night, but, gathering together in large bodies, will seek some dark corner, and pass their whole existence in one incessant and ineffectual struggle to get under each other and out of sight. In this struggle they crowd together in swarms, like bees. I have often seen a solid writhing mass of them, over half an inch deep, which could almost be covered with the hand, and which could not have numbered less than ten thou- sand.* This instinct to hide is so strong that they will dive head first, with all their might, into the gravel, and insinuate themselves into holes and chinks where you would think it impossible for anything to get, and where sometimes they can never get out again. Then woe to the little creatures if there are chinks Seventh day. Bodies acquiring decidedly more solidity. Sac more pointed. Eighth day. Fish decidedly harder, darker, and firmer fleshed. The herding-together instinct shows itself for the first time to- day. * It has been thought by some that this crowding together is hurtful, but I never knew a single fish to be injured by it, though I have sometimes turned more than twenty thousand in together at this stage. Contrary to some authorities, I keep the alevins in shallow water and a strong ripple. If they were in deep water with a slow current, I think there might be danger of injury from excessive crowding. CARE OF ALEVINS. 155 or holes in the hatching troughs where they can so entrap themselves, for they will certainly do it. The instinct is so ceaseless that it seems to drive them on farther and farther, without any thought of turning back. I have seen a thousand at a time white and dead with suffocation under a pane of glass in the hatching trough, whither this instinct had pushed them on and on to this fatal termination. Here arises a serious objection to the use of hatching troughs with uncemented glass linings. The glass prevents the growth of fungus to some extent, it is true, but there is always danger of the alevins getting un- der the glass and becoming suffocated, as in the case just mentioned ; and so invincible is their instinct to do this, that they will constantly try to return under the glass, even when they are just taken out white and almost dead with suffocation. If, however, the reader should happen to use loose glass linings, or any lining or hatching bed of any kind which the young crea- tures can get behind or under, he is here cautioned to examine every day, and see if any are hidden in dan- gerous places, and, if so, to liberate them at once It is true that after the eggs are all hatched the linings can be taken out, but as this is so difficult to do, with- out burying some of the fish under the gravel, and as it also releases the fungus behind the glass upon the young trout, the remedy is almost as bad as the dis- ease ; and besides this, it is no remedy at all for the earlier-hatched alevins, which must necessarily be ex- posed to the danger some time before the glass is ready to be taken out. 156 DOMESTICATED TROUT. And while the patent charcoal troughs can be had, it is not necessary. This irresistible instinct, which drives the alevins past all obstacles to secure a hiding- place, does not seem surprising, when we reflect that it is the only instinct, as well as the only means of self-preservation, which these very clumsy and perfectly helpless creatures have to protect themselves against their myriads of enemies. Up to the time when the first half of the yolk-sac period is passed, there is not much danger of loss, except from the little creatures' getting suffocated as just described, because they remain at or near the spot where they were born, and do not roam about much. But after the first half of this stage is over, a new instinct makes its appearance, and it is accom- panied with a new danger, which is both alarming and insidious. This second instinct of the trout is to fol- low a current of water wherever they can find it; usually, but not always, following the current up stream, and diving into any corners, however small, where their delicate perceptions detect the entrance or exit of a current of water. Then woe to the trout breeder if his troughs are not perfectly tight ! for if there is a loose joint in the box, or a nail-hole or aper- ture under or about the screen where water comes in or out, these little creatures will be sure to find it, and one by one will go through it in thousands, even if the crevice is not much larger than would admit a snow-flake. If a beginner were told how small a crevice a six weeks' trout will go through, and has gone through, he would say it was simply incredible. CARE OF ALEVINS. 157 Great vigilance is now required ; and wherever there is a suspected place, a fine wire screen should be placed below it to catch any that escape. I once noticed a drop or two of water trickling from the head of one of my hatching troughs, and immediately placed a large screen under it. Two days afterwards I found nearly a thousand young trout on the screen, although I did not then, and could never afterwards, discover any hole for them to get through. The wire netting at the regular outlet should also be particularly watched, as the constant cleaning of the screen wears out the wire, and may make a fracture in it before it is suspected. The trout at this age are the incarnation of perver- sity. They will go just the opposite way from which you want to have them, and if there is any place where you do not want them to go, they will be sure to col- lect in it in vast numbers, and when you try to drive them away they will dive their heads into the gravel and stick to the spot with a truly wonderful tenacity ; or if you succeed in forcing them off a little way, they will return with redoubled momentum, and charge again and again, with a persistency which is as sur- prising as it is annoying. As the tissue of their struc- ture is such an exceedingly delicate one that they can- not be pushed forcibly, even with a feather, they would be very difficult to manage if you wished to have them leave any particular spot where they had gathered, were it not for the knowledge of one instinct that they have. This instinct is to avoid agitated water. They have a great dislike to troubled waters, and will usually leave with one accord any spot where the water is 158 DOMESTICATED TROUT. violently disturbed, and if they have had a good stirring up will not generally return to it soon again. Therefore, when you wish to drive them out of a hole or corner, agitate the water violently with a feather, or, better yet, dip up a few cups of water and pour into the corner from a little height above. The effect will be magical. In a few moments the place which it might have taken half an Jiour to clear otherwise will be willingly deserted. Though so very frail at this stage, the alevins will stand the cold wonderfully. I have frozen them sev- eral times so that they were glued tight on to the ice and could not stir, and in most instances it did not seem to hurt them at all. I have taken pains to keep these " frozen thaws " by themselves, where they could be watched for some weeks afterwards. In some in- stances they appeared as well as any trout of their age, and showed no signs of being injured by the freezing. If, however, they are frightened while they are freezing in OF thawing out, they will, in trying to extricate themselves from their icy fetters, tear them- selves so that they will afterwards die. Alevins will also live a long while without change or aeration of the water, if the temperature is low. A hundred young alevins will live a day or two in a gill of water at 34°, incredible as it seems. This is consequently a very favorable time to transport them. As they can stand the cold, you can, by reducing the water to a very low temperature with ice, send them a great distance in small bulk without change or aeration of water. CARE OF ALEVINS. 1 59 The alevins are also very hardy, as respects general causes of sickness or injury in their every-day life. If you have run a good ripple of water over the eggs when hatching, and have kept it up with the young fish after hatching, your loss in the yolk-sac stage will be very slight indeed, sometimes almost nothing. A few will die in the act of emerging from the shell, and some will have what, for want of a better name, might be called the blue swelling* which is fatal ; but with these exceptions you will lose very few indeed from disease during the yolk-sac period. Some will be born with curved spines, or with two heads or two vertebral columns, but they are likely to live until the feeding period. It may be well to add here, that now is the time to collect any monstrosities that you may wish to preserve in spirits, such as double-headed fish, double-bodied fish, and the like. The perfectly formed fish are the most beautiful and most curiously formed in reality; but you will probably want to preserve some of the misshapen freaks of nature, nevertheless, and now is the time to do it. In this instance there is no cruelty in it, as these deformed creatures would all die a lingering death before long, if left to themselves. I never knew any of the misshapen fish to grow up, except those whose spines, after a curve or apparent joint, resume, or nearly resume, the original line of the vertebra. These will sometimes grow up and do well, even where there are two deflections or joints in the back. I sent one of that description to market year before * Green calls it the " dropsy." I6O DOMESTICATED TROUT. last that was three years old, which, from having a dark skin and a crook in his back, my friends had nicknamed the " Black Crook." The alevin stage is, on the whole, the easiest time for the trout breeder of the trout's whole life ; and if everything is right at the outset when the eggs hatch, the alevins will be almost no trouble at all. At this stage there are no eggs to pick over, no mouths to feed, not much care as to the amount of water supply, and none of the anxiety about their lives which comes a little later. This rest in the cares and labors of the trout raiser, however, is only the lull before the storm. No sooner is this stage over, and the trout get well to feeding, than work and danger begin again, as will be seen in the next chapter. CHAPTER IV. REARING THE YOUNG FRY. SECTION I. — PROGRESS OF THE YOUNG FRY, AND GENERAL DIRECTIONS. WE have now come to the most perplexing and the most inscrutable of all the branches of trout raising, namely, growing the young fry. How to hatch the eggs, which would hatch themselves if simply let alone by their enemies, was a problem comparatively easy in its solution, although this was a gr^nd achieve- ment at first, and reflects great credit on those who pioneered it through, the more because it was suc- cess in hatching the eggs that first popularized the art of fish culture and laid the foundations of the present wide-spread interest in it. But to make the young trout live, which have equally delicate and more complex organizations than the eggs, to find them the food which is wholesome for them, while it is wholly artificial, to anticipate wants which are not even known, to discover derangements of organs, when the organs themselves are microscopic, and to avert diseases without a glimpse of their causes, — in short, to make creatures live, so frail that a touch will almost kill them, and that seem to die without a cause, — this was a field of study apparently so obscure and intan- gible that it presented great difficulties. 1 62 DOMESTICATED TROUT. Here the triumphant skill which hatched the eggs successfully was baffled; and it seemed for a time as if the wonderful art which had promised so much was to come to a stand-still at this gulf between the eggs and the yearling trout, a gulf which seemed as if it could not be bridged. Those who made the earliest practical experiments in this country will undoubtedly recall, with me, the anxiety which was at one time felt lest the difficulties of bridging this chasm would prove insurmountable. This task has, happily, now been performed. Rearing young trout is no longer a problematical thing, it is. a fait accompli. The question is not now, Can young trout be raised ? but How many can do it, and under what circum- stances can it be done successfully? As the yolk sac wears off, the dense masses of little alevins begin to separate, and assume a more indi- vidual existence. They seek to avoid, rather than to crowd, one another, and their fins being developed sufficiently, they can now rise and balance them- selves in the water. The awkward, unwieldy body has acquired the graceful, symmetrical form of a fish, and each individual, taking a place for himself, heads vigorously up stream, and soon shows by his move- ments that he is on the lookout for food. I have noticed that it is almost always a matter of anxiety to beginners how they will know when it is time to begin to feed the young fry. This anxiety is wholly unnecessary, because when the trout are ready to feed, they will let you know it plainly enough by taking the food which you offer them. REARING THE YOUNG FRY. 163 You need not give yourself any trouble about the matter, till you see them all up in the water, balancing themselves nicely, and heading bravely against the current. If you now throw in a little food, or any fine particles, indeed, of anything whatever, they will, if they are ready to eat, instantly turn out of line to seize the particles floating by them. If they do this, you may know that it is time to feed them. If they pay no attention to what they see in the water, let them go for that day, and try them again the next, and so on, till they leave their places to snatch it, and from that time feed them reg- ularly every day. Once will be enough the first day, twice the second, and, after that, four times a day for two months. From this time they should be fed two or three times daily until cold weather.* I think the best food for them at first is liver, and curd made from sour milk, mixed in about equal proportions, or, still better, with two parts liver and one part curd. The young fish at this age, as may be supposed, can take only the finest particles of food. The curd, therefore, should be made as fine grained and moist as possible. The liver should also be reduced to the smallest possible particles. This is accomplished in various ways, but the way that I have found the most satisfactory and the most expeditious is to grate the liver on a common tin lemon-grater or cheese-grater. You must be careful to have the holes small enough * Young living perch and suckers would probably make the best possible food for very young trout fry, and could be obtained in vast quantities. See Appendix IX. 164 DOMESTICATED TROUT. at first to admit only very fine particles ; they should not be over one tenth of an inch in diameter. The grater should be placed horizontally on a piece of board or marble slab, and the liver grated on it ; what goes through will for the most part be fine enough for the fish to eat. There are other ways of preparing the liver, I am aware ; but you can prepare as much this way in ten minutes, as by any other method that I know of in half an hour. It was for- merly thought best to feed the liver and curd to the fish through a small fine screen, so that no particles should fall to the bottom and remain unconsumed because of being too large, but since the discovery of the use of earth in absorbing the foul matter col- lecting on the bottom this precaution is unnecessary; still there is no objection to it, except that it is not so simple and makes more work. The method of feeding adopted at the Cold Spring Trout Ponds is to mix the curd and prepared liver on a small paddle, say eighteen inches long and three wide at the blade, with a common case-knife, taking care to pulverize and separate the particles with the knife very thoroughly. The blade is then dipped in the water and the food moistened. It is then mixed and pulverized still more with the flat blade of the knife, very much as a glazier mixes putty, or a painter his paint, on a pallet. When sufficiently moistened and separated, to prevent any adhesion of the parti- cles the paddle is again dipped in the water, and little by little the food is washed off, till the fish have had enough. When you first make your appearance, REARING THE YOUNG FRY. 165 the fish, whether from playfulness or from actual fear, will dart away and try to get out of sight, but the presence of the food in the water will soon attract them again, and they will swarm around it from all quarters. If you have plenty of time and patience, and not too many fish, you can collect them all in one or two places, by waiting for them to come up ; but if you have a great many and need to be expedi- tious, you will probably resort to feeding more rapidly and in several places. You can begin feeding, if you like, with the yolk of eggs, boiled a half-hour and pulverized very fine. This is sometimes more con- venient and accessible, when you have only a few fish, than the liver and curd feed, and some persons con- tinue to use the egg for several months ; but this is not recommended. It is more expensive, it makes the worst possible corruption when it does sink to the bottom and foul the water, and I think it is not so wholesome or nutritious as a mixed meat and curd diet. Liver alone answers very well, but neither egg nor curd alone will do. It would be a great improve- ment, in the way of feeding the young fry, if you could prepare some self-acting contrivance, which would feed out the required amount of food gradually and continually all day, as, for instance, a closed box of fine wire netting, partly filled with food and placed under a fall, in such a way that the water will force out the food, little by little, all day.* The box should * This idea has been carried into execution by Herr Otto Hammerle, an Austrian fish culturist in Vorarlberg, who has in- vented a feeding-machine which is constructed on the principles 1 66 DOMESTICATED TROUT. be made so that it could be taken apart and the net- ting thoroughly washed and cleaned every day, as just mentioned. A cut and description of this invention, which Herr Hammerle has kindly furnished me, are herewith given : — 23orrtd)tung gur $wtterutt$ ber Soretten fimfUidjen gtfd)3itd 911$ Seftfcer eincr gtoar fleineren funjHtd)en goreflengud)t*2lnftalt {jabe id) nid)t fcerfaumt, 2Ritglieb bed beutfdjen $ifd)erei*2$erein$ git tterben, unb tyabe nebenbei bie fcefanntefien 2Berfe biefer Slbtljeilung bet Sanbttnrtlj* fdjaft mit grofiem 3ntereffe gelefen, unb getradjtet auf biefem ©eMete mog*= li^jl Srfa^rungen ju fammeln. (£3 gtng immer fe^r gut unb aufmunternb, Bt^ ici^ jum $apitel ber funfl=« lichen giitterung ber gtfcfye fam; ba blteb id) bann aber aud) immer ftecfen; e« jlellten ftd) re ^inburd) meine 5Wafd)ine mit gro^em S5ort^)eile benu^te, unb fie fur jeben ^tfd);sud)ter fiir unentbefyrtid) ftnbe, tt)iE id) fte fjiermtt gum 5^u^en filler pr allgemeinen ^enntni§ brtngen, 2)ie Stnrtd)tung be3 SWafd)ind)en^ befle^t t 2lu<3 einem 2Bafferrabd)en, l»eld)es5 bie 25orrid)tung tretfct* 9Tu<3 einem ^d'fldjen, tt)eld)e^ ba$ gutter (fein geftadft) aufnimmt* £5a3 ^djld)en tt)irb gu ?»ei XJritttjeilen mit SBaffer angefiittt, ba«5 gutter {jinetn* gegeben unb, wa'^renb ba3 ?Wafd)ind)en im ©ange ift, »on bem im rotirenben SBledjritbjer gleid>ma^ig mit bent SBaffer sermengt. 2)er flanb im $dftd)en fofl n>omogltd) gleid) er^alten bleiben; bte^ n?irb mit bem REARING THE YOUNG FRY. l6/ otherwise it would soon become so foul as to be cB bem $aftdjen angebradjten 9Jfi$r<$en erretcfyt, burd) tt>eld)e3 baS afegefjenbe SSaffer erfe^t n>erben fann. Slupen ant $aftd)en beftnbet ft(^ cine £efcelflap£e, tt>elc^e ft^ bur(i) btc SBettegimg be^ SBafferrabc^en^ »on 3ett gu 3ett ijffnct, unb flte§t baki mit bem SBaifcr etwa^ gutter au^. 2)Zan regulirt ba<3 Deffnen ber Self-working Machine for feeding Trout. 1 68 DOMESTICATED TROUT. injurious. Such a contrivance would save a great tnbem man meljr ober roeniger Staffer auf bad 2Bafferrdbdjen fliefjen lafjt, mit bcm an ber 2Bafferleitung fceftnblicfyen £>af)ne. Urn bad 2lnf)cingett son gultert^ei(d)en am untern £f)eite bed ^aficfjend itnb ber $Iawe ju tterfyuten, roirb burcf) bad angefcradjte Olofjrcfyen mtt SBaJTer bie Sftflufjoffnung bed ^cijidjend fceftdnbig abgefpitlt. 3um 33etrieoe ber gangen gittter^25orric^tung tjl bad 2Bajfer einer circa §toei Md brei Sentimeter weiten 0Io^re not^tg. 2)ad 2ftafer=* ben (am beflen mit ©cfyroeinefett), bamit ed leister Iduft. 2)a3 2)?af^in^en fott n>enn moglic^, unb genug ©efatt »cr^anben tfl, circa breifjig Senttmeter iikr ber Dkrflacfje bed SSafferd bed Safftnd an* ge&radjt roerben. SJort^etlc biefer SSorrtdjtitng: S)ad ^uttermafc^inc^en Ia§t nitr ganj wenig, b. ^. bad not^ige gutter, in fur^en 3eitraumen ben Sifdjctyen gufommen ; bad gutter wirb ba&er »ott* f^anbig serjetyrt, unb baburc^ bie ©efa^r »on SSergiftungen bur^ SSerroefung ber ^utterrefte auf bent ©runbe fe^r bebeutenb »erringert. 3)ad Saffin mu§ nicfyt fo oft gereinigt roerben. SWan erjielt ein raftered unb gleic^ma'§igered 2Bac|)dt^um ber 5ifd)(^ett. 2Benn 3. S3. bad 2ftafdjtndjen afle groei ?Winuten einen S^loffet »off gutter ben ^ifAd^en iufii^rt, fo fann man annetymen, bap jebem, aud) bem fc^rodc^*' flen ^ifdjc^en, ©etegenfyeit getoten ijl, ben hunger gu flillen. 2)ad 2Bafl"er, welded auf bad SBafferrabdjen fdttt unb babitrdj bie 33or^ ric^tung in 33e»egung erfya'lt, jlurjt »on bemfeloen ind 33afftn, roirb bat>et soHfldnbig jert^eitt, fd)roangert ftc^ mit Cuft, unb roirb atfo fiir bie $ifdjd)en sorjugtic^. 2)ad ?Kaf(i)tn^en ifl in $otge be(Jen fcefonberd fiir foldje 3tnflalten, roelc^e nur DueHroaffer tyakn, fe^r gu empfe^Ien. 2)a bie giitterung burc^ biefed SWaf^inc^en fef)r erleic^tert roirb, fo fonnen $ifct)$udjter, roetc^e bie junge S3rut audfefcen rooKen, baffetoe fo lange fo* nufcen, Bid bie ©elegen^eit jum 5ludfe^en paffenb i|l, road mir fefyr »or- t^eil^aft erfc^eint. £)0rnbirn (in 25ora(krg, Dejterrei^), im Sanuar 1876. C)tto REARING THE YOUNG FRY. 169 deal of time and trouble in feeding, and seems to be [TRANSLATION.] Self-working Machine for feeding Trout in Artificial Fish Breed- ing Establishments. As proprietor of a small Trout Breeding Establishment, I have not neglected to become a member of the German Fish Society, and have also read with great interest the celebrated works on this branch of husbandry, and have endeavored to col- lect all the information possible in this direction. All was favorable and encouraging until I came to the com- mencement of the artificial feeding of the fish, but then I came to a standstill. Difficulties placed themselves in my way, and I began to think that I should be obliged to give up the propa- gation of my trout. It was in the winter of 1873 and 1874, as I was preparing myself for the coming spawning season, that I came across the new work, " Domesticated Trout," by Livingston Stone, which again encouraged me to succor my little fish. On p. 153 of his work Mr. Stone writes thus : — " It would be a great improvement in the way of feeding the young fry, if you could prepare some self-acting contrivance which would feed out the required amount of food gradually and continually all day." I tried my best to carry out the ideas of the celebrated Amer- rican fish culturist, and constructed the enclosed photographed feeding machine. Now, after using my machine for two years with great advantage, and finding it for all fish culturists indis- pensable, I wish herewith, for the use of all, to bring it to gen- eral notice. The arrangement of this machine consists of a small water- wheel which works itself. A small box which receives the food (finely chopped) is filled two thirds full with water, the food put in, and while the machine is in motion equally mixed with the water by means of a rotating metallic stirrer. The height of the water should always remain the same if possible. This is accomplished by means of the pipe in the box by which the outflowing water can be arrested. On the outside of the small box is a lever valve, which by I/O DOMESTICATED TROUT. a more natural and wholesome way than to gorge means of the motion of the little water-wheel opens from time to time and some of the food is given out with the water. The opening of the valve is regulated by letting more or less water flow into the water-wheel with the faucet found on the conduit. To guard against the adhesion of the little pieces of food to the under part of the box and the valve, the discharging opening should often be cleaned with water passed through the tube. To work the whole feeding machine a pipe from two to three centimetres in diameter is required. The machine ought to be kept very clean, and should be lubricated from time to time, as all mechanical contrivances should be, in order that it may run more easily. The machine should, if possible, and if there is enough fall of water, be placed about thirty centimetres above the surface of the water in the basin. Advantages of this Machine. The feeding machine allows but little food to come to the fish at short intervals. The food is therefore entirely consumed, and consequently the danger of poisoning by putrefaction of the un- eaten food on the bottom of the basin is very greatly diminished. The basin need not be cleaned very often. A rapid and equally developed growth of the fish is obtained. Since, for example, the little machine conveys to the fish two table-spoonfuls of food every two minutes, it follows that an opportunity is offered even to the weakest fish to appease its hunger. The water which falls on the little water-wheel, and by means of which the machine is kept in motion, tumbles into the basin. Thereby the water is separated and aerated, which is also of great advantage to the fish. Thus it follows that this machine is much to be recommended for those establishments which only have spring water. The fact that feeding is made much easier by this machine, so that fish culturists can use the same until the opportunity comes to let the young fry free, appears to me very advanta- geous. REARING THE YOUNG FRY. I/I them at intervals of three or four hours, and keep them in abstinence the rest of the time. When the young fry have eaten enough is a question not easily settled, although it has been asked very many times. I used to think that they would not eat too much, and I cannot now say that I ever knew of an instance of a death caused directly by over-eating ; and, as a general thing, I still think there is more danger of not feeding enough, than of feeding too much. On the other hand, overfeeding may possibly increase the liability to disease, when the fish are very much crowded. I do not believe that when there is plenty of room and water, they will ever eat enough to hurt themselves ; but when you have many confined in a small space, I would advise the exercise of some caution about overfeeding. The most destructive instance of the ravages of disease in my experience was with the best-fed trout I ever had. The contents of two boxes, twenty thou- sand young fry, were attacked by parasites, which swept them all off in one week. On Monday morn- ing they were the most robust and best-fed trout f had ever seen of their age, and on Saturday night the whole twenty thousand were dead. No others were attacked. I do not know that overfeeding had any- thing to do with the appearance of the parasites. I only mention the coincidence for the benefit of future observers, and would add that I think that over- crowding the fish had much more to do with their death than overfeeding. As a rule then, I repeat, you need not be afraid of the young fry's eating too much. 1/2 DOMESTICATED TROUT. Their digestive organs are wonderfully active, and they will digest * almost as fast as you can feed them, and you will need a good deal of patience to feed till they refuse to eat. I never knew any healthy young fry of mine to decline eating but once, and then I had them fed incessantly for two hours, at the end of which time they gave up beaten. The young fry will repay you well for feeding them well, for there is hardly any creature which shows the effects of good feeding so quickly and strikingly as young trout. They appear sometimes to grow, almost like flies, on ample allowance, and one or two good meals will make a hungry young trout seem to double his bulk, and this is not wholly an illusion either. But although they are not likely to eat too much, they will not only at this age, but at all ages, take too large pieces of food at a time, and will sometimes kill themselves in this way. When you find a trout dead, with his head much swollen laterally, and both eyes forced outwards, you may know that he killed himself by bolting his food. We have said nothing so far in this chapter about removing the young fry from the hatching troughs, and, indeed, this removal is not necessary for a week or two. The young fry will do as well in the hatch- ing troughs, if the water is raised an inch or two, as anywhere else at first, but they must be thinned out very soon after they begin to feed. If you engage in * Bertram compares the digestion of some fishes' stomachs to the action of fire. Harvest of the Sea, p. Lyman says of pickerel, that they are " mere machines for the assimilation of other organisms." Mass. Fisheries, Report, 1871, p. 17. REARING THE YOUNG FRY. 1/3 the business of selling young fry, this thinning out will come naturally in the course of your sales, and will need no special attention ; but if you do not sell them off, you must take out enough from each box or trough to leave only a safe number together. The number which it is safe to leave in a given space you must learn by experience, as so much depends upon the water supply, the character and temperature of the water, and other circumstances, that the number cannot be set with much definiteness for all places. You need not, however, be afraid to keep two hun- dred to the square foot, if they are shaded, till the first of May. By that time they will be ready for their summer quarters. You will notice that the young fry in the troughs, soon after beginning to feed, will seem to divide into two bodies, one consisting of the larger and stronger ones, at the head of the trough just below the fall, and the other consisting of the smaller and weaker ones settling down towards the outlet screen. The division into these two classes will be main- tained with more or less distinctness through the year and afterwards. The cause of the separation is, that some are really weaker and smaller than others, and these will avoid the more violent water and the pres- ence of the larger ones, who would drive them away if they tried to stay with them. This division of the two classes becomes more marked as they get a little older, because the weaker ones are driven back and are obliged to take the food, the water, and the range that is left them by their superiors, who are all the DOMESTICATED TROUT*. time getting the lion's share of everything. The effect, of course, is to increase the contrast more and more every day. This effect can, however, be offset, in some degree, by taking pains to give better care and feed to the lower ones, and this should always be done. Indeed, by feeding the lower ones more than usual, and neglecting the upper ones, you can bring them somewhat together in point of locality, though never in point of size. I think that it is also a good way to take out all the lower division, and put them in an enclosure by themselves. They will never be as large fish as the others, but they will then, at any rate, be freed from the tyranny of the larger ones, and will im- prove correspondingly. You may notice, too, that sometimes some of the lower young fry get against the screens, and perhaps die from the effect of it. There is no need whatever of this. If they get against the screens, it is because they are weak, and you may know that their weakness has come either from their being too much crowded, too little fed, or from being actually sick. The remedy for the first and second is obvious ; and the third case ought not to have occurred; but in all three cases more feeding will bring them up. They are weak, and need to be fed to be made strong again. Therefore, when the little creatures get against the screens, or show a tendency that way, feed them more, and con- tinue doing so till they come up strong again. Do not turn down the water, as is sometimes done, when they are weak and get against the screens, for this only makes them weaker ; but keep the water on, un- REARING THE YOUNG FRY. less it was too violent to begin with, and make the fish come up against it by feeding, which they will do if not sick or too crowded. There is a little trick which should be ' practised on them when they show this tendency to collect too much at the lower screen. It is well known that trout seek the deeper places and darker bottoms of any shallow stream. By taking advantage of this instinct, you can make most of your trout stay where you wish ; so when they collect too far down the trough, fill up the lower end about half an inch or an inch deep for a foot or so from the screen with light-colored sand. This will make the water more shallow here, and the bed of the trough of a lighter shade, and the fish will abandon it at once for deeper and darker places farther up stream. The force of the current is now, of course, increased near the outlet by this change, and an inexperienced person might suppose that if the young fry were collected down near the screen in slow water, they would be carried down much more by swift water. But this is an error. If the fish are not sick, their desire to get out of the shallow, exposed place will make them stem the cur- rent till they find a place above it less objectionable to them. The worst possible thing you can do, if you want to keep the young fry away from the screens, is to make the water slower by deepening it at the screen. It has just the opposite effect from that which is sought. For the first two or three weeks after beginning to feed, — we are now supposing that the young trout 1/ DOMESTICATED TROUT. remain in the hatching troughs, — the appearance of things is very bright. Indeed, there is no more hope- ful time in the trout breeder's year than that when the young fish just get to feeding well. The dangers and hardships of the long winter's hatching are over. He has a fine lot of healthy, thriving trout They feed well, they look well, and do not show a sign of a pos- sibility of their dying. Everything goes on swim- mingly, and unless he is more than human, or less, he will invariably draw the flattering picture to himself of what these thousands of tiny things will be three summers hence, each weighing a half-pound apiece or more. It is certainly an elating prospect. But behold, at the end of about three weeks, an ap- palling change comes over this happy vision. It comes on very unobtrusively in the beginning, and the first sign of it which you discover is merely the gathering of two or three fish in a corner where the water is stiller than the rest. On examination, you observe nothing unusual about them, except that, to use an expressive Dutch-Americanism, they appear " logy/'* avoid the running water, and eat languidly, or per- haps do not eat at all. This seems a very trifling circumstance ; but to an experienced eye it is start- lingly significant, for it is sure to be the forerunner of wholesale disaster. The next day the number of disaffected ones will be increased to a dozen, perhaps, and very likely some of them will be heading down stream. This number will steadily increase. Soon they will begin to drop down dead, by ones and twos * From the Dutch log, dull, stupid. REARING THE YOUNG FRY. I// at first, and then by dozens, then by hundreds, and, unless some remedy is applied, seventy-five per cent will die the next month, and perhaps all j and many of them — we are still supposing that they have remained in the hatching troughs — will have a little round ulcer just on the top of the skull, which, when pricked, will discharge a thin, watery fluid. This is the stage, I take it, where Green's book says of their dying, that the cause is not known, nor the remedy. I must disagree with him. The cause is known, and the remedy is known also. The cause of this mortality is twofold. In the first place, the food which has been given them has to some extent, however carefully it may have been fed out to them, fallen to the bottom, and has formed a thin layer over the gravel, which has now- had time to become putrescent and has fouled the water with its exhalations. In the second place, the diet upon which the fish have been kept, although the best known and very nu- tritious, is deficient in some element indispensable to the health of the trout. It is like the experiment of feeding the dog wholly on olive oil, — the most nutri- tious thing in the world, — but which soon brings on an ulcerating disease that kills him in not many weeks. The remedy for both these causes of disease is the free application of common earth, and it is a certain and effective one. I was led to this discovery somewhat in this way : I found my young fry dying by thousands, as just described, and those that were left losing their appe- tites and avoiding the current. I felt sure that the DOMESTICATED TROUT. fine, thin film of mouldy matter which could be seen on the bottom was fouling the water, and I removed the fish to clean the troughs. This revived them some- what, and they began to eat again, but they lacked their natural vivacity and looked lank and ill-favored. I then began to reflect carefully on the matter, and it occurred to me that their artificial food might be want- ing in some tonic element, indispensable to health, and that liver and curd and nothing else might be to trout what olive oil and nothing else was to the dog. The symptoms certainly indicated it. I might have got no farther, but I noticed that some of the young fry, which by accident happened to be where the mud was occasionally disturbed, did better and appeared thrifty. I also remembered that the wild trout in the natural brooks are never so lively and voracious as just after the streams have been mud- died by a shower. Then it suddenly flashed upon me, that mud or earth, with its multiplicity of constitu- ents, might possibly contain the deficient element At the same time, I remembered the great absorbing power of earth, which might perhaps absorb the foul exhalations from the bottom, at the same time that it supplied the needed tonic. I shared the common prejudice against muddying the water where the trout were ; but the crisis was an imperative one, and I determined to solve the problem. I poured in earth, enough to cover the bottom half an inch, making the water so thick with mud that every fish was obscured with it. I watched anxiously for the water to clear, to see how they came out of it. REARING THE YOUNG FRY. 1 79 The effect was magical. It had revived them all. A change for the better was decidedly noticeable at once. In twenty-four hours the sick ones were nearly them- selves again, and in two days they were all better fish than they ever were before. On another occasion large numbers of my young fry had become sickly and were failing rapidly. They had begun to collect against the screens, and there was evidently a bad time coming very soon. This was on the 5th of March. This time they had been feed- ing only about two weeks. I applied the earth plen- tifully, with the same effect as before. On the yth they were much improved. On the 8th they were all well again and off the screens. Earth or mud is the last thing one would suppose suitable for a fish, so associated in our minds with pure, clean water ; yet it is an indispensable constituent in the diet of young trout, and unless they get it, either naturally or artifi- cially, they will not thrive. I repeat once more, we are supposing the young fry to be in the hatching troughs still, and supplied with water from the spring. Of course, if they are nourished with brook-water, which brings down more or less mud with it, this dis- ease will not break out, and the fish will not require the artificial introduction of earth ; but they must get it in some way, and unless it is already in the water, it must be furnished artificially, or the fish will lan- guish.* I am not prepared to say what kind of earth is the * I have sometimes found the stomach of a wild trout nearly half full of gravel. ISO DOMESTICATED TROUT. best, but I think that the earth from just under a toler- ably rich sod is as good as any, if not better. It is a very good way to put the whole sod in the trough or box. The fish will get off of it what they want, and the presence of the vegetable growth in the water is favorable to their health. Muck I have sometimes thought the best, and it is said to be the most powerful of earth absorbents, but I have also had misgivings that the muck sometimes had something injurious in it. It may be only a fancy, however. At all events, the earth just under a fresh green sod answers the purpose, and is good and whole- some. The application of the earth should be renewed as often as the fish seem to require it, and, indeed, it is best not to wait till they show signs of wanting it, but to give it to them often, and keep sods in all the time ; and whenever you perceive anything in the troughs that is likely to foul the water, throw a handful of earth over it. If you have a pride in keeping a clean gravelly bed to your troughs, you can cover over the earth, after a day or so, with clean gravel, and it will look as well as before ; but you must give them earth again soon. As the spring advances the young fry will continue to grow, and one day's routine in taking care of them will be very much like another through the summer. This does not imply, however, that the work is mo- notonous or dull. On the contrary, it is exceedingly interesting, and the more closely you observe them the more interesting the care of them becomes. You will learn to distinguish individuals from one another, and REARING THE YOUNG FRY. l8l to notice individual peculiarities ; and it will be a source of great pleasure to see them growing daily in strength and stature, and taking on by almost imperceptible degrees the ways and appearance of mature trout. Indeed, you cannot spend an hour or so a week more profitably than by studying the little fellows minutely, with your eyes as close to the surface of the water as you can get. This is the way to study them ; and if you want to obtain an insight into the nature of trout, and have signal success in raising them, this is the thing to do. The young fry in their growth probably will not keep pace with your wishes at first. Still they are really growing rapidly, and if their apparently slow progress makes you impatient, take out one of them any time in the summer and compare it with one of your preserved specimens of a day old. You will be gratified with the contrast, and will see that they have doubled their size many times over, though they had appeared to remain nearly stationary. They are also getting their flesh hard and solid, as you may see by taking out a four weeks' trout on a piece of board or glass and letting it dry, and doing the same again in the summer with a six months' trout. The first speci- men will leave hardly more than an impression of the fish's form, as thin as tissue. The second will show solidity as well as figure. The young fry will continue to grow and require more food until winter sets in. In the mean while they will demand constant watching and care, the nature of which will be described more fully in the 1 82 DOMESTICATED TROUT. next chapter, and also in the one on the diseases of young trout. SECTION II. — WHAT TO DO TO MAKE YOUNG TROUT LIVE. i. Have healthy, well-fed breeders. When a young trout drops down dead during the first few months of his life, a beginner is apt to think that the cause origi- nated the same day or the same week, which is as unphilosophical as to suppose that deaths among the human race, resulting from feeble constitutions or hereditary consumption, were caused by something that happened the day or the week on which the death occurred. To discover and remove the causes of death among young trout, we must go back of the young fish's life, back of the eggs themselves, to the breeders which produced the eggs. This is self-evident, and yet it is often overlooked. In order to have healthy fry, you must have healthy eggs. To secure healthy eggs, you must have healthy, well-fed breeders. The progeny of puny, half-starved, half-suffocated fish cannot be as strong and healthy as those of well-grown, well-fed fish, with plenty of range and water. Therefore, if you want your young trout to live, give your breeders a good supply of water, feed them well and regularly, and keep them in good condition, especially from May to November. Large eggs, on the whole, are better than small ones. They produce larger fish; and, other things being equal, REARING THE YOUNG FRY. 183 the larger fry, it is observed, thrive better than the smaller ones. Now the secret of getting large eggs is not to use large-sized breeders, for a two-pound brook trout pro- duces no larger eggs than a half-pound brook trout, though they are more in number. Large eggs are the result of keeping the breeders in water that warms up in the spring and summer. It is true, if it becomes too warm, say above 70°, it is injurious; but water that stands at 65° in the summer will make larger eggs than water at 55°, and very cold spring water, say at 45°, will always develop small eggs. The rea- son is obvious. We know the rule is throughout the animal kingdom, that warmth, when not extreme, fa- vors growth, and as the temperature of the fish's body corresponds to the temperature of the water,* it naturally results that the eggs developed in the warmth of 65° will be larger than those developed at the cold point of 45°. 2. Develop strong and healthy embryos in the egg. You must not suppose, when you find your trout dy- ing in April and May, that the mortality is necessarily caused by something that has happened since they hatched. The causes may date back half-way through the period of incubation or more. I have seen trout embryos with the eye-spots just appearing, which I knew could not live three months after coming out, although they hatched like other eggs, and seemed like * The temperature of the fish's body follows the temperature of the surrounding water, but keeps a little, perhaps two de- grees, above it. 184 DOMESTICATED TROUT. other trout for weeks. The reason was, that they were sickly and feeble embryos, which had not vitality enough in them to grow up. In order to have strong and healthy trout that will live, you must have strong and healthy embryos to begin with. This is so obvious, that it seems trivial to mention it. Yet I have seen persons treat eggs in such a way that the fish from them could not possibly live to grow up, and wonder three months afterwards what made them die. To insure strong and hardy embryos, the suggestions in the chapter on hatching eggs should be carefully observed. The eggs should not be crowded too much. They should have plenty of water, though not too much, running over them. This water should be in constant circulation. The two kinds of fungus, alga and byssus, should be abso- lutely excluded. All sediment should be kept from the eggs, and, in the writer's opinion, they should be hatched in the dark. If you observe these rules, you will have strong and healthy trout from your eggs, and of these rules I should say that the most important are, to avoid fungus and still water. 3. Provide a suitable place for the young fry when they begin to feed. We remarked that the hatching troughs would do very well for the young trout for the first few weeks after feeding. This is true, if the fish are thinned out sufficiently, and a clean layer of gravel or sand put over the winter hatching bed ; but the hatching troughs are not favorable to growth, and usually are not so convenient for feeding as other places in which the fish might be kept. It is therefore REARING THE YOUNG FRY. 185 desirable to change them before summer, and it is very important to put them in a suitable place when they are changed ; and to effect this the following points should be secured, namely : — The young trout, when removed from the hatching troughs, should be kept, — Where they will feed well. Where they will be safe from their natural enemies. Where nothing can get in and nothing can get out. Where no fungus can come to them. Where the water cannot run oven Where they cannot remain permanently out of sight. Where the water supply cannot be cut off by accident. Where the fish can have new, unused water. Where they can find shade. Where there is plenty of room. The first six points were fully unfolded in the chap- ter on rearing boxes ; so I will here simply refer the reader to that chapter, and pass on to the considera- tion of the remaining points. It is essential that the young fry be kept where there is no possibility of the water supply being cut off, even by the most unexpected accident. It is ^^possibility that you want to guard against, not the probability. My excuse for mentioning so obvious a principle is, that persons are so careless about this very thing. Though they may have expended hundreds of dollars to get their fish where they are, and have taken pains to have everything else safe, they will sometimes leave a faucet or a spout in such a way that it is quite possible for some accident to close the faucet or mis- 1 86 DOMESTICATED TROUT. place the spout, and cut off the whole supply of water from the fish below. I recall now several instances in which most disas- trous results have been so caused. This point is the more important, because the consequences of neglect are so very fatal ; in the hot weather, when the young fry are being raised, two hours without ch'ange of water being often sufficient to kill a whole box or pond full. They should be kept where new, unused water will run over them. This is very important. At first, when they begin to feed, the effete matter coming from them is very slight in quantity, and harmless ; but it rapidly increases with the growth of the fish, and becomes a prolific source of impurity and disease, as can be easily comprehended when it is considered what the amount must be from one thousand to ten thousand fish feeding almost hourly. The water, therefore, that is used for the nursery, should be fresh from the spring or brook, and should not be that which has run over other trout above, un- less the stream has run far enough to purify itself. The place in which they are kept should be well shaded. Sunlight fosters the growth of fungi and con- fervae, and predisposes the young fish to some of the diseases to which they are subject ; and when disease breaks out it makes bad matters worse. The young fry should be therefore guarded against it, as well as the eggs. Shade never killed a trout yet, young or old. Sunlight has killed a great many. It cannot be denied that trout often come out voluntarily into the sun, but they should nevertheless always be placed so REARING THE YOUNG FRY. l8/ that they can take their choice, and not be obliged to stay in the sun because there is no shade. Their place of confinement must not be too much crowded. Be very careful to guard against this, and do it in season. It is very injurious to keep young trout too close together. They will not grow as well. The water breathed over so many times becomes vi- tiated ; the foul matter thrown off by the fish in- creases the evil ; and in time disease will break out among them, and rage all the worse because of the very thing that caused it, namely, the overcrowding. Anything which combines all the points above men- tioned will answer for a nursery for the young fry, wheth- er it is a pond, or trough, or rearing box, or what not. I recommend the use of a rearing box, because it does embrace these points. Anything else that does will answer as well, but it will be a rearing box still, either on a large scale or a small one. It is the com- bination of principles which makes the rearing box, and not its name, or form, or material. It should be added here, that is a good plan to keep water plants* in the nurseries of young fish. I will not say that it is indispensable, but I think it is very important in- deed. Trout consume oxygen, and return carbon. Water- plants consume carbon, and return oxygen. By put- ting plants and fish together, therefore, we avail our- selves of one of nature's great universal agencies in balancing vital forces against each other, and main- * For list of water plants suitable for trout ponds, see Appen- dix III. p. 295. 1 88 DOMESTICATED TROUT. taining the equilibrium on which the continuance of organic life depends.* This is a good a priori reason in itself. Besides this, we have the facts that the plants do in practice improve the water, prevent disease, give shelter to the young fry, and furnish more or less nat- ural food for them. They also absorb much of the feculence of the fish for nutriment, f The larger the young fry grow, the larger the place they can be trusted in ; and it is never desirable to keep them in a smaller place than perfect safety requires ; for the more range they have, other things being equal, the better they will do. Accordingly, as they continue to grow, increase their range, and by the ist of Septem- ber or a little later, when they take their food like old trout, that is, spring for it from their lair and whirl, they can be put into a pond suitable for larger trout, and treated very much as the larger trout are treated. By this time they are much hardier, and less suscep- tible to invisible sources of injury ; they do not stay away alone and get lost, they are better able to take care of themselves ; you can throw them their food very much as you do the larger fish, and they can * Self-preserving aquaria have been contrived by lining the sides and bottom of a tank with the most oxygen-giving water plants, so that the fish (not trout} confined in them have lived without a change of water. I am told by a gentleman who has had experience with Barnum's aquaria, that the fish kept in these self-preserving tanks without change of water thrived better than those in the ordinary tanks which had water running through them all the time. t The introduction of fresh-water snails accomplishes the same end, but snails are destructive to fish eggs and very young fish. REARING THE YOUNG FRY. 189 be trusted in a trout pond proper. The pond, how- ver, must be covered, and the fish must still be pro- tected from rats, minks, snakes, and especially herons and kingfishers, which will destroy great quantities of them, if allowed to. 4. Take good care of the fish. Now, having bred from a healthy stock, and having developed strong, healthy embryos, and having provided a suitable place for the young fry, only one thing more is required for success, and that is to take good care of them. If you take good care of trout, I think there are ninety chances in a hundred that you will raise them. I know that there is a good deal of scepticism (I beg the reader to excuse the digression which follows) about the practicability of keeping young fry alive through the first six months of feeding, and I am aware that some of the best authorities say that a con- siderable percentage will die unavoidably during that time. Mr. Stephen H. Ainsworth, in a letter to the writer, once said that a considerable percentage of the eggs when impregnated were premature, and conse^ quently produced an imperfectly developed fish which could not live. Theodore Lyman, in the Report of the Massachusetts Committee of Fisheries, 1870, says : " All remained remarkably healthy till May, when a certain number were observed to be weakly. It is likely that they were naturally sickly, and, when the yolk sac was gone, they had not enough vitality to feed."* And Seth Green speaks in his book on trout culture as if there were necessarily a great mortality * Massachusetts Fisheries, Report, 1870, p. 33. IQO DOMESTICATED TROUT. among the young fry, and says, " We don't know what is the matter with them, nor how to cure them."* Now I wish at the outset to express distinctly my deference to authorities so high, — indeed, I know of none higher, — but I must, nevertheless, venture to disagree with them if they mean that there is any necessary inherent cause of death in the young fry which cannot be removed. Some will die, say five per cent, though it ought to be less than this, of weak constitutions. They are born into the world so weak- ly constituted that they cannot stand the wear and tear of life, and must die. I admit that there may be perhaps five per cent of these necessary, unavoidable deaths; but that the rest come into being already doomed to premature death, or that young trout have any mysterious or peculiar inherent cause of death in them, any more than young calves, or pigs, or chick- ens, I do not believe. In the present state of infor- mation of the art, young trout fry may be more liable to accidents than other young domesticated creatures, and it may be more difficult to guard against their diseases ; but this is another thing. Careless breed- ing may, and careless hatching certainly will, pro- duce a progeny of young trout of which ninety per cent will die ; but this is also another thing. Careful breeding and hatching will produce trout which are just as likely to live, in my opinion, as the same num- ber of lambs or chickens ; and if the young fry die, it is not because of any mysterious, innate cause peculiar to them because they are trout, but it is because they * Trout Culture, p. 42. REARING THE YOUNG FRY. IQI were killed, deliberately killed, by external causes, just as much as lambs or chickens are killed by storms, or by parasites, or from starvation or poison. It is true that they are killed from ignorance of their wants, and not from wilful neglect, but it is the same thing abstractly, — the cause of death is external and removable, and not innate and necessary. Their wants are peculiar, of course, and more occult and in- tangible than those of pigs and colts, and to a begin- ner it will sometimes seem as if they died without be- ing diseased. But if they were as large as pigs and colts, and could be studied as easily, I do not think their wants would be found to be any more mysteri- ous or peculiar ; and if the causes of disease could be magnified, so as to be observed and studied clearly, I think that no more trout would die when nothing was the matter with them. I am furthermore convinced that study and expe- rience will eventually clear up this subject, notwith- standing the difficulties which surround it, and that at some time it will be known how to raise trout, and make them live, as well as it is known how to raise turkeys and chickens. I believe that there are energy and intelligence enough now interested in the cause to accomplish this end. I take this ground, partly because any other is unphilosophical and uncompli- mentary to the intelligence of those who are study- ing the art, and partly because the facts of experience confirm it. Who that sees the healthy young fry and yearlings and two-year-olds in Dr. Slack's ponds in New Jersey, or at Mr. Dexter's at West Barnstable, 1 92 DOMESTICATED TROUT. or Mr. Furman's on Long Island, can doubt that others can raise them in other places and make them live. The beginner may accept these axioms in raising trout : — 1. No trout dies without a cause. 2. The causes of death are discoverable. 3. They can, in most instances, be removed. My own experience has invariably been to confirm these principles. I lost in my apprenticeship days as many young fry as any one else ; but with every death, say over five per cent, there appeared a distinct assign- able cause, present or remote, which could be re- moved or avoided next time; and the more I lost the more I became satisfied that the causes of death among the young fry could be discovered and avoided. My later experience has added confirmation to this opinion. And now, since I have used charcoal troughs and tanks altogether, deaths among the young trout have been, among some lots, rare occurrences, and in general have been no more frequent — over the five per cent weak ones — than among the yearlings and breeders. In one charcoal trough, in particular, containing over five thousand, there was, in the season of 1870, less than one per cent of deaths from all causes in three months. It has been the same this year (1871). In one box of a thousand I have not taken out ten dead ones in three months. I attribute this in a great degree to the use of charcoal in hatching, but it con- REARING THE YOUNG FRY. 193 firms the theory just advocated, that the causes of death can be removed. This has been a long digression, I know. I beg the reader to excuse it. I was saying that if you took good care of the young fish, hatched and pro- vided for them as has been suggested, there were ninety chances out of a hundred that you would raise them. This remaining contingency, however, of tak- ing good care of them, is no trifle. It involves constant vigilance and a very faithful attention to all the con- ditions upon which the life and growth of the young trout depend. As any further directions as to the care of them would be a repetition of what has already been written, I will merely advise the beginner to be always on his guard against accidents and dangers ; to visit the fish the first thing in the morning, and the last thing at night ; to carry out Macbeth's resolution, " to make as- surance double sure," even if it seems like taking a "bond of" certainty. And now, hoping that the reader will have the best of luck during this delicate period of the trout's career, let us pass on to the consideration of the unpleasant but important subject of the diseases of young trout. SECTION III. — DISEASES OF TROUT FRY. We are now come to the department of trout cul- ture which is the least known, namely, the diseases to which young trout are subject. This is an almost un- trodden field of study,* where little is known, and * The art of raising horses and other domestic animals has IQ4 DOMESTICATED TROUT. still less recorded. It is important, however, that this department should not be overlooked, partly because no art which has for its object the cultivation of any creature can be considered perfected without a knowledge of its diseases ; and, especially, because the diseases of young trout are often clandestine in their operation and epidemic in their effect, so that, when the ravages of disease break out, they are pecu- liarly widespread and fatal, and rapid in their work. I therefore venture, though with some timidity, to give the reader the little knowledge which I have gathered on the subject from observation of the trout under my care, with the hope that others will follow in the same path, and supplement my scanty notes with more valuable information ; and I wish to say that I claim neither appropriateness in the names of the diseases mentioned in this chapter, nor perfect cor- rectness in the diagnosis. I only give the plain re- sult of my incidental observation, without pretending to great thoroughness or scientific knowledge of the subject. The diseases and causes of death which have come under my notice among young fry are as follows : — 1. Fungus on the egg. 2. Partial suffocation of the embryo. 3. Strangulation of the embryo in hatching. 4. Seth Green's dropsy, or blue swelling. books on their diseases, and we know where to go to find horse" doctors and dog-doctors and the like; but no book has been written on the diseases of young trout, and I suppose there never was in all the world such a thing as a fish-doctor. REARING THE YOUNG FRY. 195 5. Deformity at birth. 6. Fungus on the surface of the body. 7. Constitutional weakness. 8. Emaciation. 9. Starvation. 10. Ulcers on the head. 11. Animal parasites. 12. Fin disease. 13. Black ophthalmia. 14. Irritation of the optic nerve. 15. Inflammation of the gills. 1 6. Black gill fever. 1 7. Fatty degeneration of the vitals. 1 8. Spotted rash. 19. Strangulation by food. 20. Cannibalism, nibbling. 21. Overheating. 22. Suffocation. 23. Paralysis. i. Fungus on the egg. This is the most insidious, the most devastating, and the most obnoxious of all the diseases of young trout, and the first in order of the causes of death. It blights the embryo in the egg. Once present in the water, it spreads unseen over all the eggs, and is sooner or later fatal. The effect of fungus has been already described in the chapter on Hatching the Eggs, p. 127. We mention it here again among diseases of trout fry, because it sometimes does not kill the eggs, but causes them to produce prema- turely a weakly young fish, which usually dies before summer. 196 DOMESTICATED TROUT. For causes, signs, and remedies of fungus, we refer the reader to the chapter on Hatching the Eggs, pp. 127,128. 2. Partial suffocation of the embryo. It sometimes happens that the embryo will be partially suffocated a short time before the egg hatches, so that, although the embryo will be born alive, it will die soon after. The cause of this, of course, is not giving the eggs air enough, either from overcrowding them or not having enough circulation in the water. The remedies are obvious. 3. Strangulation in hatching. Sometimes the em- bryo dies just in the act of hatching. I have attributed it to the strangulation of the embryo by the shell of the egg. It may be from other causes. There is no remedy that I know of, and the instances of death from this cause are not numerous enough with trout to make it a very serious matter.* 4. Seth Green's dropsy, or blue swelling of the yolk sac. This is a very noticeable disorder among the alevin trout, and, being an affection of the yolk sac, is of course confined to them. The sac becomes swollen to three times its usual size. The outer membrane shows very thin and trans- parent, is seen to be filled with a bluish liquid, and, when punctured, discharges a thin, watery fluid. Seth Green's book calls it the dropsy; it affects only a * Mr. Parnaby, of Troutdale Fishery, England, says he has noticed this cause of death particularly in the char (Salmo umbla), and he attributes it to the tough shell of the char egg and the peculiarly round and full form of the yolk sac, which makes it more difficult for the char to liberate itself from the egg than for other fish. REARING THE YOUNG FRY. few fish and is not contagious. I know of no special cause and no remedy. Green says the fish can be sometimes saved by tapping the sac and letting out the dropsical matter; but I doubt it, and think the disease is always fatal. 5. Deformity at birth. Some trout are born with curved spines, spiral spines, double heads, and with bodies more or less imperfect. The proportion of these to the whole is generally small, though the num- ber of deformed spines will be made considerable by careless hatching. Unless the deformity is slight, the fish will not live long after feeding, although a double fish, with two distinct vertebral columns and separate tails, and united only at the sac, will survive for some time. If the deformity is trifling, they sometimes live. I have killed several grown-up trout with somewhat bowed and crooked backs. Careful hatching is the remedy for deformed spines, or rather the preventa- tive. 6. Fungus on the surface of the body. This cause of mortality is distinct from fungus on the egg, as it attaches itself to fish hatched from perfect eggs. The fish usually get the fungus on them when quite young, by rubbing it off the sides of the box or pond in which they are confined. It sometimes floats down with the water and gets in their gills. It is always fatal, and usually very destructive. It cannot be too carefully guarded against. There is no remedy for the disease after it attacks the fish, unless it is salt water.* It can be prevented only by shutting off any possibility of * See Appendix I. 198 DOMESTICATED TROUT. fungus growing in the hatching troughs or coming into the water. This can be done by the use of carbonized troughs and aqueducts throughout. 7. Constitutional weakness. This is an evil which is the necessary lot, we suppose, of a certain propor- tion of all domesticated creatures that are born into the world. This proportion, in the case of domesti- cated trout, can be reduced very much by careful breeding and hatching ; but there is, nevertheless, a limit as with other creatures, beyond which the causes lie too deep and too far back to be controlled. What the limit is with trout is not known. I think Mr. Ainsworth's opinion is, that the percentage of loss from this cause is very large with artificially taken eggs. I think it is much less, and with care in developing strong and healthy embryos need not be over five per cent. The constitutionally weak ones may be distinguished from the rest by being at birth thin, puny, undersized, and looking as if they never, would come to anything. There is no help for them, but the number of them can be much reduced by care in the development of the embryo. 8. Emaciation. Many of the young fry are usually observed to wear away without any visible cause. They do not wholly decline food, but grow thinner and thinner every day, tilfat last they die. This emaciation, although the effect of disease, is classed here among diseases, because the causes are not known. If sufficiently studied, the disorder would probably be found resolvable into some of the other diseases here mentioned. These attenuated fish may REARING THE YOUNG FRY. 1 99 not always die, but I do not think them worth the trouble of raising. The best thing to do with them is to turn them out into a natural brook, and let them shift for themselves. They may come to something there. They never will in the nursery. 9. Starvation. This, Seth Green thinks, is a prolific cause of death among the very young fry, and it does not follow that they will escape because their keeper takes pains to feed them ; for, if confined in ponds of considerable size, they will often wander off where they can find no food, and from shyness and ignorance will not come up to take it when offered. The con- sequence is that they are soon carried against the screens, or drop down dead from exhaustion, forty- eight hours of fasting being enough to reduce very young fry to a state of extreme weakness. I have often thought also, that, when very hungry, they will eat things which do not agree with them, and so hasten their death. The remedy for the danger of starvation is to con- fine the trout where they will take their rations regu- larly and feed them faithfully. Then you will not lose any from this cause. 10. Ulcers on the head. This disease has already been mentioned in the chapter on growing young trout. It usually attacks the fish, if at all, when they are young, and always comes when the water gets foul from decaying food, and when the fish have no earth. Great numbers died of it before the use of earth as a remedy was discovered. As this disease progresses, the fish becomes lank in body, its head 2OO DOMESTICATED TROUT. swells and grows soft, and an ulcer appears on the top of the skull, which discharges a thin, watery fluid when punctured. It is not contagious, but always fatal. The remedy is found in prevention. It is to keep the water pure, and give the trout plenty of earth. ii. Animal parasites -.* This is a very alarming and destructive cause of death among the young fry, and all the more because the parasite attacks the best and fattest and healthiest fish. They come suddenly and unexpectedly, sometimes as early as the ist of May, and first show themselves as a little bunch of whitish jelly-like matter on the back or sides of the fish, in most cases not far from the dorsal fin. At first the fish does not appear to mind it much, and feeds and remains in good condition for a day or two. But soon after he seeks an eddy where the water is still, refuses food, and dies within a week. This dis- ease is fatal, and whether contagious or not, it is cer- tain that whole boxes are attacked at once, and in the instances within my experience every fish was de- stroyed in ten days, none escaped ; it is the most fatal and insidious disorder that I have encountered in raising young fry. The microscope which I used for examination revealed nothing but a gelatinous protuberance on the body of the fish. I have sup- posed it to be the eggs of some water insect floating in the water, but provided with the power of attaching itself to whatever it fell upon, like the eggs of perch * See Appendix I. for account of another class of animal parasites, not discovered when this chapter was written. REARING THE YOUNG FRY. 2OI and other fishes. I have therefore called it an animal parasite, though future observation may prove this to be incorrect At first sight one would take it for the fungus, which is so common among injured fish ; but a little examination shows it to be quite different, affect- ing the fish differently, and, what is the worst feature about it, attacking perfectly healthy, uninjured trout ; the largest and most promising being among the first of its victims. In my experience, the parasites have not, I think, originated always or usually in the en- closure where the fish were, but somewhere above in the stream, where they are generated, and whence they float down to where the fish are which they fasten upon. The fish that are affected cannot be saved, but the spread of the disease may be checked by prompt measures. Therefore, as soon as the presence of this disease is discovered, take out the affected ones and throw them away. Then change all the others to a new place where you can depend upon the water, and lose no time in doing it. 12. Fin disease. At all stages of growth during the first six months, the fins of the young fish may sometimes be observed to be mutilated. Occasionally as many as one fourth of them will be found to be so affected. Sometimes the fins will be simply a little frayed at the edges, at other times the fin will be seen to be nearly gone, and will present a fungussy edge. The affected ones will usually gravitate towards the outlet screens, and will be the weaker and smaller ones of the lot, but occasionally a .large and vigorous 202 DOMESTICATED TROUT. one at the upper end will have a fin or two half gone. This disorder is not always fatal, by any means, for some will recover ; but if either of the pectoral fins are nearly destroyed, or if fungus has set in, the trout will probably die. One cause of this disease is the biting of other fish. Young trout, like cub bears, are irritable in their na- ture, and do not like to have others come too near them, but will snap and bite their companions when they show a disposition to crowd. The result is that their fins frequently get mutilated, and present the appearance just described. They show this irritable- ness especially when they are left unfed for a while and get very hungry, the hunger, perhaps, having a double agency in making them bite at each other. This unnecessary cause of the evil should at least be avoided. When you discover any young trout with injured fins, take them out and put them by themselves, where they have plenty of room, plenty of water, and plenty of food. Some will die, per- haps half. With the others the fins will grow out again, and the trout in a few months be as well as ever. 13. Black ophthalmia. This is a strange disease. You sometimes observe a fish becoming very black and inclined to separate from the rest. He is some- what emaciated, refuses food, and is less easily fright- ened than the others. If you examine his eyes, you will see that the tissue of the pupil is more or less destroyed and his eyesight much injured, which is the cause of his not being frightened at your approach. REARING THE YOUNG FRY. 2O3 The emaciation continues, the blackness of the skin increases ; the fish finally becomes totally blind and dies. I know of no cause or remedy, though I have noticed that more cases occur where the water has become somewhat foul, and once I thought a fish affected with this disorder recovered on being removed into better water, but I do not feel certain of it. The disease attacks young and old alike, and is not conta- gious. 14, Irritation of the optic nerve. Fishes, as is well known, have no eyelids to protect their eyes from excessive light. It is therefore a very serious thing to young fry, that have been used only to the dark, to be suddenly exposed to the glare of the sun ; and it some- times happens that when they are so exposed, and cannot escape from the sunlight, their brains become hurt, they assume most unnatural positions and move- ments, and after darting about frantically, like crazy creatures, for a few moments, they die. I have sup- posed that the unaccustomed light produces an irrita- tion of the optic nerve, and have so named it. 15. Inflammation of the gills. This corresponds to inflammation of the lungs in animals, and it is the re- sult usually of cro'wding too many trout into too small a space, without a sufficient change of water. Their gills or lungs have too much work to do, and this, with breathing over the impure water, produces inflamma- tion. It is a lingering disorder, more in that particular like consumption in higher orders. The affected fish may contrive to live for some time, and eat the same, but will not grow any; they will become attenuated, and 2O4 DOMESTICATED TROUT. finally die. I am inclined to think, however, that the disease is not always fatal, but that a change to puie water and plenty of it will often effect a cure. The ap- plication of earth in this disease seems injurious, rather than beneficial, probably owing to the irritating action of the sandy particles on the inflamed tissues. You can detect the disease before death by looking directly down on the fish from above. In a perfectly healthy fish the gill covers completely cover the gills, and shut down closely over them. In a sick fish the gill covers do not wholly conceal the gills, which are visible through the whole respiration of the fish, and appear swollen and inflamed. After death the fish looks so much like a perfectly healthy fish, that an inexperi- enced person would say there was not a mark of dis- ease upon it. Deaths from this cause are very pro- voking to beginners, for the fish seems to them to die without any cause whatever. 1 6. Black gill fever. There is another disease of the gills, which is more rapid in its action, and to which I have given the above name because it seems to resemble a fever, and because the gills of the fish turn black. I have not had many cases of it myself, but I believe it is usually fatal ; others who have ob- served it think that it is contagious. I know of no remedy. 17. Fatty degeneration of the vitals. Sometimes when you examine a young trout that has died without a visible cause, you will find an abnormal accumulation of fat about the vitals, and nothing in the stomach. This is probably the cause of its death. There is, as REARING THE YOUNG FRY. 20$ is well known, a corresponding disease among higher orders, called fatty degeneration of the heart. Dr. Slack of the Troutdale Ponds speaks of this disease among trout, and says that a constant diet of curd will produce it. 1 8. Spotted rash. I once gave an abundance of water-cresses (Nasturtium officinale) to a lot of young fry that had been kept wholly without vegetable food. In forty-eight hours their bodies were covered with brown spots, and within the next forty-eight hours most of the fish died. I cannot say for a certainty whether it was a rash coming from within, or a parasite coming from without. I have called it spotted rash for want of a better name, and have noted it for future observers. Whatever it is, it is certainly very fatal. 19. Strangulation by food. Trout of all ages will sometimes take too large pieces of food, which they cannot disgorge, and which they cannot swallow, and therefore get choked to death. You will see them in the pond with their eyes protruding, and head very much swollen laterally, and the offending morsel sometimes projecting from the mouth. The situation is usually fatal, but not always ; they will sometimes recover, after having had a frightfully swollen head and eyes ; sometimes you can save them by pulling the piece of food out of their throats. 20. Cannibalism, nibbling. This is a frequent cause of death among the young fry. Trout are cannibals ; they will always eat each other, if they can, when they are hungry ; and this can be taken as a rule, that a trout of any size, if hungry enough, will eat a trout of half its 206 DOMESTICATED TROUT. length. A trout a foot long will eat a trout of six inches, or a trout two inches long will eat a trout an inch long. Cannibalism is something, too, which grows on trout; and after having once tasted flesh of their own kind, they, like human cannibals, prefer it, and, refusing their ordinary food, they will lie in am- buscade in holes and corners, where, feeding on their weaker fellows, they thrive and grow better than the rest. This makes the evil doubly mischievous, be- cause from their new habit of hiding they are less likely to be discovered, and their increased rate of growth is daily putting a greater difference in size be- tween them and their companions, and making them more formidable. Careful sorting is the remedy, to- gether with regular feeding. If these rules are ob- served, there will not be much trouble or loss from the trout eating one another. But there is another form of cannibalism, which, though less repugnant, is more injurious, namely, nibbling. The young fry when they first feed are very voracious, and will nibble at the tails and fins of those in front of them, and, if allowed to get very hungry, will often do a great deal of injury in this way, especially if much crowded. The younger they are, the more they are given to the habit, but they finally outgrow it. The remedy is to give them regu- lar feed and plenty of room. 21. Overheating. This simply means being kept in water that is not cold enough. As summer advances and the weather grows warmer and warmer, the wa- ter in your brook sometimes grows too warm for the trout to live in. If that is your coldest brook the REARING THE YOUNG FRY. 2O/ consequence is inevitable. The trout must die. This cause of death is trying, because you can see the trouble and know what is coming, but cannot help it. If you have colder water, remove the fish to it without delay, and take the first hours of the morning in which to do it, when the water is coolest ; use ice in convey- ing them. If the heat is only exceptional, you can do some good by the use of ice placed in the inlet. I have saved some in that way ; indeed, as long as the ice lasts you are safe, but it wastes very rapidly in run- ning water, and therefore is often unavailable. The dangerous point of temperature lies somewhere be- tween 70° and 85° Fahrenheit. I have known water to be fatal at 72° or 73°, and I have known trout to live in good vigorous water at 78°, but danger is near when the mercury begins to be above 70°. 22. Suffocation. This is simply the result of want of air, from the water having been breathed over too much. The cause and remedy are obvious. I will only say that the colder the water the slower trout breathe. In case of suffocation, the fish should not be given up because it appears to be dead, for suffocated trout are often restored, even after life seems to be entirely extinct. The way to do this is to aerate the water in which they are contained as vigorously as possible. The effect is often very startling, as well as gratifying, in bringing to life fish that appeared dead. In concluding this chapter on the diseases of young fry, I would recommend to the trout-breeder to ex- amine his trout carefully every day, and to be always 208 DOMESTICATED TROUT. on the watch for the appearance of disease, and, when he detects its presence, to act promptly on the maxim in the beginning of Seth Green's work on fish culture, "Never put off till to-morrow what you can do to- day." The progress of disease among young trout is often so rapid, and so epidemic in its character, that you cannot be too vigilant in discovering it, or too prompt in suppressing it. I would add, also, that you must not suppose because none of your fry are dying that no disease is in progress, or that dis- ease has just set in when the fish begin to die. On the contrary, in some instances the disease or offend- ing cause may have been at work for weeks before the first fish actually dies from it. Therefore be vigi- lant and prompt in guarding against the first approach of evil. 23. Paralysis. There is still another disease to which young fry are subject, and I should call it par- alysis if I thought that fish were subject to this dis- order. It attacked one lot, and only one, of my alevin trout. They had been hatched about a month, and the yolk sac was nearly half gone. There were, perhaps, about two thousand in the compartment. Sixty or seventy were attacked. The first time I discovered that anything was wrong was one morning when the water was being agitated with a feather. The well ones immediately headed with all their might against the current as usual, while a few, only fifteen or sixteen at first, were observed to lie perfectly mo- tionless, and to move unresistingly with the current, and finally to collect in a heap in the centre of an REARING THE YOUNG FRY. 2O9 eddy. On examination they appeared to be perfectly lifeless; but they did not — and this is the singular part of it — they did not change color, as dead fry of this age invariably do. The next day, and for two or three days, they continued to look like live fish as they lay still in the water, and to appear like dead fish when more closely examined. After three or four days one or more white spots were seen near the heart, and these finally extended all over the body: but the entire white change did not come on for a number of days, and always began internally and worked outwards. Sixty or seventy were affected in this way. All died ; but the others in the com- partment did not seem to suffer at all, and remained alive and well. SECTION IV. — FILLING ORDERS FOR YOUNG FRY. Filling orders for young fry in the spring is part of the trout-breeder's business, and promises to con- tinue to be, on the principle that people will buy their young fish to save hatching them, as people buy young cabbage-plants and tomatoes to save starting them. A few words about sending off the young fish may be of service to the beginner. The first thing to do in preparing to fill an order for young fry is to arrange temporary boxes to put them into after they are counted. These boxes should have a stream of water running through them, should be provided with an ample screen for an outlet, and should be light and portable, so that they can be lifted, and the fish and water poured from them when 2IO DOMESTICATED TROUT. wanted.* The boxes should be perfectly clean, so that there will be nothing but the fish and the water to pour out. The next thing is to count them. To do this, net out a quantity from the hatching-troughs into a pan of water. Place this pan side by side with a large can or pail of water. Then take a dipper and dip up a few fish from the pan and pass them over to the pail, counting each dipperful as it is passed over. You had, perhaps, better begin with only four or five in the dipper at once, but with practice you will be able to count seven or eight or more at a time as you pass them over. It takes from half an hour to an hour, according to your dexterity, to count a thousand. It is a good plan to score every hundred, so that, if you lose your count, you will not have to go back far to recover it. It is very easy to forget your count, and very provoking to be obliged to count over again two or three thousand because of forgetting the exact num- ber ; but if you score every hundred there is no danger of being driven to this. The temporary box for the night should be in place when you begin to count them, so that the counted fish will not be obliged to stay long in the pail or can. If there is a large num- ber to send off, they should be counted the day before, and placed in the boxes, fed well, and covered over for the night. They will then be in good condition to start the next day, which is a very important point. * In transferring young fry from one receptacle to another, it is easier and safer to pour them over, water and all, than to net them out. If the fry are very thick, it is sometimes best to transfer part of them with the net, and pour over the rest. REARING OF THE YOUNG FRY. 211 In the morning feed them again, and when it is time to start, transfer them to the tank or can which is to carry them. For small quantities, say 1,000 or 2,000, I use a twelve-gallon tin can. For larger quantities, say 5,000 or more, I take a seventy-gallon tank, a drawing of which may be seen in the Massachusetts Report of the Fishery Commissioners for 1868, Plate III. Fig. 6. The tank has a pump attached ; but this is not worked when small fish are carried. I use also a hundred- gallon tank for moving still larger quantities. The tank for carrying fish, when filled with water, is very heavy, and should have four iron handles on Conical Tank for the Transportion of Young Fry. 212 DOMESTICATED TROUT. the sides to facilitate moving. It must not be made too large round, or it will not go into the door of the Conical Tank for the Transportation of Young Fry. express-car, which would be found to be a very seri- ous difficulty. The best form that I have found for a tank for trav- elling with live fish is the conical one given in the accompanying plates. The advantage of the conical shape is, that the water, on being agitated by the mo- tion of the car or vehicle in which it is carried, aerates itself by spurting up the sides of the cone and falling back into the tank, in consequence of which the tank becomes, when in transit, a self aerator. The tanks are sometimes made of wood and some- times of tin. The measurement of three different sizes used at the Cold Spring Trout Ponds are as follows : — I. Height 48 inches. Diameter of bottom . . . . 29^ " Diameter of opening . . . .17 " Diameter of top . . . . 9 " . REARING OF THE YOUNG FRY. 213 2. Height 38^ inches. Diameter of bottom . . *.- . » „. 25 " Diameter of opening .... 14^ " Diameter of top . . » . 4 " 3. Height 30^ " Diameter of bottom . . . . 19 " Diameter of opening . . . . n " Diameter of top * 4 " A A, C C. Tank. A, B, A. Lid to tank. A A. Junction of tank with lid. In travelling long distances, I take, besides the tank,* a water-pail, a bag of ice, tin dipper or bellows, and a sponge. The ice will be all needed before night, if the weather is warm. The pail is a convenience in various ways, the dipper or bellows t is for aerating the water, and the sponge is for the floor of the car, if the water slops over. Be careful to have plenty of help when you load into the car, and also at every change of cars, for, different from other merchandise, an upset is often a total loss.$ Keep the temperature of the water very low all day with ice, — using large pieces when standing still, and small pieces when in motion, as the large pieces are then apt to bruise and kill the fish. Do not change the water en route, but give it a thorough aeration once in half an hour. The aerating will be sure to keep * The Troutdale Transit Tank is recommended as an excel- lent thing to carry live fish in. See Dr. Slack's Catalogue of fish culturists' apparatus. A common flour-barrel, well soaked, with floats on the top of the water to prevent slopping, is a very good impromptu affair for carrying live fish. t A common hand fire-bellows is as good an extempore aerat- ing machine as can be found. | See Appendix II., on Journeys with Live Fish. 0* THB 214 DOMESTICATED TROUT. them alive, while there is always a risk of killing them by using water with which you are not acquainted. It is best, I think, to accompany the fish all the way, and see them safely in the hands of those to whom they are consigned, though, where there is no change of cars to the end of the route, I sometimes leave them the last fifty miles, with a small fee, in the hands of the express messenger. Alevins require less air than older fish, and no food, consequently more can be taken in less water than when older, and the risk of loss is correspondingly less, making the alevin stage the best time for trans- portation. But, as you cannot sell all your fish at the alevin stage, you will probably have occasion to trans- port the young fry at various ages. This is always practicable ; only it should be remembered that the older they are the more water they require. A thousand alevins can be carried in a gallon of water, kept very cold. At the age of three months I allow a gallon of water for each two hundred feeding fry. In brief, then, when you transport young fry, count them the day before, start them in good condition, go with them, keep the water very cold with ice, do not change it, aerate it regularly, and do not upset the tank, and you will find the fish will do almost as well on a journey of twelve or twenty-four hours as if they were at home in the stream. I have carried ten thou- sand young fry, four months old, all day in hot weather, from 5 A. M. to 6 P. M., in fifty gallons of water, without change, and with a loss of only seven fish out of the ten thousand. See Appendix, on Journeys with Live Fish. CHAPTER V. GROWING THE LARGE TROUT. SECTION I. — TROUT IN GENERAL. Scientific Description of the Salmo Fontinalis. By David Humphreys Storer* SALMO FONTINALIS. Common Trout. Mitch- ill, Trans. Lit. & Phil. Soc. of N. Y., I. p. 435. Salmo nigrescens. Black Trout. Raf., Ichth. Ohien., P- 43- Red-spotted Trout. Doughty, Cabinet of Nat. Hist., I. p. 145, PI- 13- Salmo fontinalis. Rich, Fauna Boreal. Americ., III. p. 176, PI. 83, fig. i., PI. 87, fig. 2, head. Salmo fontinalis. Common Brook Trout. Storer's Report, p. 1 06. Salmo fontinalis. Speckled Trout. Kirtland's Report, pp. 169- 194. Salmo fontinalis. Brook Trout. Thompson, Hist, of Vermont, p. 141. Salmo fontinalis. Brook Trout. Dekay's Report, p. 235, PI. 37, fig. 120. Baione fontinalis. Spotted Troutlet. Dekay's Report, p. 244, PI. 20, fig. 58. * A History of the Fishes of Massachusetts, by David Hum- phreys Storer, 1867, pp. 322, 323, 326. 2l6 DOMESTICATED TROUT. Salmo fontinalis. Brook Trout. Ayres, Bost. Journ. Nat. Hist., IV. p. 273. Salmo fontinalis. Common Brook Trout. Kirtland, Bost. Journ. Nat. Hist, IV. p. 305. Salmo fontinalis. Common Brook Trout. Storer, Mem. Amer. Acad., new series, II. p. 444. Salmo fontinalis. Common Brook Trout. Synopsis, p. 192 j Cuv. & Val., Nat. Hist, de Pois., XXI. p. 266. COLOR. — The upper part of the body is of a pale brown, mottled with darker undulating, reticulated markings ; the sides lighter, with a great number of circular yellow spots, varying in their size from a small point to a line or more in diameter, and many of them having in the centre a bright red spot ; sometimes, the yellow color surrounding them having partially disap- peared, they seem distinct from the circular spots, or are surrounded by a dull bluish halo ; these red spots differ exceedingly in number in different specimens, in some three or four only are observable, and those are situated below the lateral line ; in others, twenty or more are seen, scattered above and below the lateral line indiscriminately, presenting a beautiful appear- ance. The body beneath is white, yellowish-white, slightly or dark fuliginous. Head above darker than the back of the fish. Gill-covers golden, and fuligi- nous. The dorsal fin is yellow with irregular trans- verse black bands. The first ray of the pectorals and ventrals is white, the second dark-colored, the remain- der of the fin is red. The first ray of the anal fin is white, the remainder generally red. The caudal fin is of a dirty reddish -brown, mottled with black spots. GROWING THE LARGE TROUT. 2 I/ DESCRIPTION. — Body elongated, compressed. The length of the head is about equal to one fifth the length of the fish ; the top of the head is flattened ; the snout is obtuse. The eyes are large and circular. The distance between the eyes is equal to one fifth the length of the head. The jaws are equal in length ; the gape of the mouth is large ; the teeth are sharp and recurved ; the teeth on the tongue are larger than those of the jaws ; there are teeth also on the palatines and romer. The scales are very small ; those on the lateral line, which pursues a straight course, are larger than those on the rest of the body. The quadrangular dorsal fin is situated upon the anterior half of the body; the adipose fin is quite small, and near the tail. The pectorals arise in front of the posterior angle of the operculum ; their length is equal to one quarter of their height. The fan-shaped ventrals commence opposite the middle of the dorsal fin ; when unexpanded, their ex- tremities together form a sharp point. The anal fin arises in front of the adipose fin, and is higher than it is long. The caudal fin is deeply emarginated. The fin-rays are as follows : D. n, P. 13, V. 8, A. n, C. 19. Length, eight to twenty inches. Labrador : H. S. Storer. Maine, Massachusetts : Storer. Connecticut : Linsley, Ayres. Vermont : Thompson. New York : Mitchill, Dekay. Pennsyl- vania: Dekay. Ohio: Kirtland. Lake Huron : Rich- ardson. 2l8 DOMESTICATED TROUT. GENERAL REMARKS ABOUT TROUT. The trout has always stood at the head of the fresh- water game fishes in the popular estimation. The fickle public may change its favorite some time for a more admired successor, but up to this time the trout has distanced all rivals. This honorable place he has gained and held, not by accident, but by merit. He deserves to rank by himself //-.$•/, for where has the trout his equal ? There may be fish of nearly as fine flesh as the trout, but they have a repulsive coat, like the pout ; or a coarse appearance, like the bass ; or a disagreeable one, like the mascalonge ; or are full of bones, like the shad ; or have no game in them, like the mullet ; or fail somewhere to match the excellent points of the trout. There is not one of them that for perfect faultlessness can compare with the trout. This is his special peculiarity. He is faultless. He surpasses all other fish in grace of form, in beauty of coloring, in gentleness of expression, in fascina- tion of manner, in gameness of spirit, in sweetness and firmness of flesh, and in general personal attrac- tiveness, and to excellence in these points he also combines faultlessness in all others. Hence it is that he is the favorite among fishes, and deserves to be so. Trout are peculiarly suited to domestication, being very hardy, easily tamed, conveniently confined, satis- fied with plain food, well adapted to artificial breed- ing, prolific enough to increase rapidly, and having a sufficiently high value as live game, or as a table lux- GROWING THE LARGE TROUT. 219 ury, to make it worth while to raise them. I will not attempt any exhaustive description of these beautiful fish here, as they are so well known, and have been so thoroughly described in books on angling and on fish in general, but will confine myself to the few general remarks which follow. The vision of the trout is incredibly sensitive to motion and to colors, but not to distinctions of form. As to their sensitiveness to motion, it may be safely said that a company of soldiers standing motionless on the bank of a trout brook would not frighten the trout in it so much as the moving shadow of one of them across the water. Their sensitiveness to colors is seen every week at the ponds where trout are domesticated, especially when their keeper changes a dark coat for a light one, or leaves it off altogether. The appearance of the un- accustomed light coat or white shirt will often frighten well-tamed trout into a panic. Trout do not appear to see their food at any great distance in clear water, — I should say not over a rod, and in roily water but a very short distance, some- times not a foot. Trout can see somewhat in the night, but I think not in as dark nights as some writ- ers have stated. If the sky be clear, they will de- tect an object on the surface of the water, projected against the sky, better than in the water, projected against the banks. A moving light above the water in the night will frighten trout ; a stationary light in the water will attract them, and apparently stupefy them, for they are easily captured while staring at it 22O DOMESTICATED TROUT. The eye of the trout has very convex lenses, and is not provided with lids or any other shield whatever from the light. This makes bright sunlight sometimes fatal to young trout which have passed their embryo period in the dark. The eyes are situated above the line of the widest part of the head, and are a little protuberant, thus enabling them to see above, before, behind, and around, but not below them. Hence they cannot feed off the bottom, except at random. They will dart at a piece of food on the bottom, hit or miss, if they have seen it fall ; but you can see that they feel for it with their mouths, rather than catch it with their eye, and their movements are also then very bungling compared with their swift, certain aim at any- thing above them in the water. They will sometimes poke the food off the bottom with their noses high enough to see it, and then they will take it as well as ever. The peculiar position of the eyes of the trout has been sometimes overlooked in the controversy of fish- ing down stream versus fishing up stream. But it is, nevertheless, not true, as advanced in the argument against fishing up stream, that the angler must neces- sarily throw his line over the fish's head to attract his notice to the bait, and so be liable to frighten him ; for the trout can see the bait if above and consider- ably behind him, and will whirl and take it so placed, if disposed. Opinions are divided about the sense of hearing in trout. I think that there never was a controversy in the world in which assertions on the subject were GROWING THE LARGE TROUT. 221 more positively made on the one side, or more flatly denied on the other. Scott says, very decidedly, in his Fishing in American Waters,* "Fishes hear; of this I feel quite sure," and quotes instances of fish coming to be fed at the sound of a bell. Seth Green says, in his Trout Culture,! that trout cannot hear, and that " they will not stir a fraction of an inch at the sound of a gun fired one foot above their heads." I will not say that trout cannot hear ; but this I will say with the greatest positiveness, for I have tested it repeatedly, that they are not frightened at noises, how- ever loud, nor do they pay the slightest attention to them. You may place your mouth directly over the trout in a pond, and if they do not see you, you may scream with all your might, or ring a bell as loud as you please, and the trout will not move a fin to show that they are either frightened or attracted, or that they have in any way noticed it. You may even fire a revolver, or, as Green says, a gun, very near them, and if they do not see the flash or feel the concussion they will not notice it any more than if they were stone-deaf. $ * Fishing in American Waters, p. 38. t Trout Culture, p. 58. J Although trout do not hear they are exceedingly sensitive to concussions. The following description of the ear of a fish is given by J. V. C. Smith : " Fishes have no external ear, nor is there any visible opening, except in the skate. But there have been so many quarrels between anatomists on the subject that all the skates in the ocean would not pay for the paper which has been wasted about a little hole in their head. Therefore, we shall be careful about getting into the ring. Fishes have just so 222 DOMESTICATED TROUT. On the other hand, if you are in the habit of calling the trout with a bell to be fed, and have found that they come at the ringing of it, go to the pond some day at feeding time with the tongue taken out of the bell, and shake it as usual. The trout will come to be fed exactly the same, though not a sound is made. The nerves of smell in trout are large, and the sense of smell is probably well developed. Hence the use of fragrant oils and strongly scented bait in fishing for trout. HABITAT. Brook trout abound chiefly in cold, swift-running gravelly brooks ; but they thrive in all pure cold wa- ters which contain sufficient air. Hence brook trout are found in many ponds and lakes, which apparent contradiction of terms has frequently led to confusion among those unfamiliar with fishing. I may be, there- fore, excused for saying, by way of explanation, that the name " brook trout " is not confined to trout caught in brooks, but applies to all of the varieties of Salmo fontinalis, whether found in brooks, ponds, lakes, or rivers. Their range is very extensive, covering a wide belt from one end of our continent to the other. In phrenological language, their locality is very large, which gives them a strong attachment to places. In much acoustic apparatus as constituted the central portion of the ear in man, viz., the vestibule and semicircular canals, but the whole is boxed up in the solid bones of the skull, so that sound propagated through the water gives a vibrating motion or tremor to the whole body, and which, agitating the auditory nerve, pro- duces the sensation of hearing." GROWING THE LARGE TROUT. 223 brooks, certain individuals will take up particular holes or rapids for their abode, and occupy them for months, and sometimes, I am inclined to think, for years. In lakes and ponds, the shoals of trout have, like perch and other fish, particular resting-places, where they stay regularly. This is one reason why a person acquainted with their haunts will go out and catch a string of trout, while others, with better tackle and equal skill, will fish a whole day for them in vain. The largest trout in brooks are found in the deep wide pools in the warmer waters. The smallest ones are found in the cold, narrow mountain rivulets near their source. The largest brook trout of all are found in large lakes, where range, space, feed, warmth of water, and perhaps inherited tendencies, all combine to pro- duce a large race. Trout, like other fishes, have small brains compared with the higher animals, and are very slightly sensi- tive to pain. They have a rapid digestion, which, though not equal to that of a pickerel,* and some warm-water fishes, makes them susceptible to very quick growth indeed under favorable circumstances. Trout have this peculiarity also, that they vary from one another in their personal appearance to an endless degree. No two trout are alike. Every trout has its individual markings, as much as human beings, which distin- * Most fish have a rapid digestion. Bertram compares the digestion of some to the action of fire. Harvest of the Sea, p. 4. 224 DOMESTICATED TROUT. guish it from all other trout. A mullet caught in a lake looks like all the other mullets of the lake, so with the white-fish and others ; but each trout has its individual marks which distinguish it from all others. The trout also of different brooks and lakes all differ from one another, so that the streams in which they are caught can frequently be told by the looks of the fish. Their different localities in the same stream also affect their appearance. Over a light gravelly bot- tom the trout grow light-complexioned, and they vary through all shades of complexion, from this to the dark slimy trout, almost as black as a bull-head, which is caught in shady places over black, muddy bottoms. And what is still more remarkable, trout have the chameleon gift of almost instantly changing their tint within certain limits.* They do not, strictly speaking, change their color, because a black trout will remain a black trout and a silvery trout will remain a silvery trout wherever you expose them; but a complete change comes over their whole complexion, so to speak, as if the light to which they are subjected were diffused through them, so that, in passing from a dark, muddy bed over light gravel, they will in less than a minute take the general hue of the gravel, and vice versa in passing from gravel to mud.f The natural food of trout is very various. They are carnivorous from choice, though omnivorous in * The black bas* and some other fish have the same power to some extent. t This change takes place, not in the scales, but in the skin underlying the scales. GROWING THE LARGE TROUT. 22$ emergency. Their food, when wild, consists chiefly of water insects, smaller fish, larvae, fish eggs, crusta- cea, and the flies and insects which fall from the air into the water, — all of them together forming an astonishingly extensive variety. They also eat each other, and there are some individuals which adopt cannibal habits altogether, and remain hidden, like spiders, in dark holes and corners, and only emerge to devour their like. The quality of their food affects the growth and ap- pearance of trout, and it is even thought that the dif- ference in the color of their meat is sometimes caused by certain kinds of feed ; the fresh-water gammari or pulex being supposed especially favorable to the pro- duction of red-meated trout. There are different theo- ries about it, however. It is certainly true that their growth depends very much upon the nature of their food. Francis, in his Fish Culture, mentions the following experiment, of which he says he once heard.* " Equal numbers of trout were confined for a certain time by gratings to their several portions of the same stream. The fish in one of the divisions were fed en- tirely on flies, in another upon minnows, and in the third upon worms. At the end of a certain period, those which had been fed on flies were the heaviest and in the best condition, those fed on minnows oc- cupied the second place, while those fed on worms were in much the worst order of the three." f * Francis on Fish Culture, p. 113. t The result of these experiments should be received cau- 226 DOMESTICATED TROUT. The age to which trout live is not known. Seth Green says that twelve years is probably about the average age, and that they are in their prime between the age of three years and ten years. I am inclined to think that they live to a greater age than this. Other kinds of fish in parks in the Old World are known to have attained enormous ages,* and to have been equalled only in their longevity by the human race before the flood. Why should the trout be so short-lived ? Mr. Lancaster, of Oxford, in a memoir published last year, says that fish have great tenacity of life, and mentions a carp that reached the age of 150 years, and a pike, 19 feet long, that lived in a fish- pond in Germany 267 years. f He says whales are believed to live one or two centuries. The size to which brook trout may grow is very un- certain, and when we come to the question of the size of those that have been actually caught we are on mythical ground. The trouble is, as Green mentions, that many of the " fish stories " which are told are so tiously, as it is doubtful whether all the other modifying condi- tions were so exactly alike that the results were wholly due to the difference of food. For illustration, a considerable difference in temperature, or in the quantity of food, would affect the condition of the fish more than the difference in the nature of the food. * Pike and carp in artificial ponds have been repeatedly found with gold rings in their fins, and other kinds of labels, on which were found dates that proved conclusively that one hundred years had elapsed since the inscription was made. — J. V. C. SMITH, JVat. His. Mass. Fishes, p. 57. t The greatest wonder about such a fish, if he were in this country, would be that had he escaped the poachers so long. GROWING THE LARGE TROUT. 22/ incredible * that they throw discredit on even well-au- thenticated cases. t I am fortunate enough, however, through the kindness of George Shepard Page, Presi- dent of the Oquossoc Angling Association, and B. F. Bowles, Esq., a member of the same Association, to cite three instances of unquestionable authenticity, of trout (Salmo fontinalis) actually caught, which weighed between 9 and 10 pounds. They are as follows. In September, 1867, Mr. Geo. S. Page caught at the outlet of Rangeley Lake, Franklin Co., Maine, two male trout, one weighing 10 pounds, the other 9! pounds. In June, 1871, Theo. L. Page, Esq., caught a trout in Mooseluc Maguntic Lake, in the same county, weigh- ing 9! pounds. These are the largest brook trout in regard to which I have succeeded in obtaining well- attested statistics, after making inquiries in various di- rections } and I think it is safe to venture the assertion that these trout, if not the largest individuals ever caught in this country, are representatives of the largest type of the Salmo fontinalis in the United States. \ The weight of trout is very deceptive. There * A famous fish-story teller once said that he cut a hole through the ice at Lake Erie, not more than two inches across, with his pocket-knife, and presently pulled out a mascalonge that weighed a hundred pounds. On being asked how he drew so large a fish through so small a hole, he replied that he had not thought of that. t Trout Culture, p. 45. \ The following letter gives a fuller account of the large trout caught by Mr. Page : — 10 WARREN STREET, NEW YORK, August 14, 1871. LIVINGSTON STONE, ESQ. DEAR SIR : In reply to yours of the 5th instant, making in- quiries with regard to brook trout, I have much pleasure in men- 228 DOMESTICATED TROUT. is no safe test but the scales. The length is no guide, for his depth and breadth will often in a short trout more than compensate in weight for what is lacking in length, and then again a lean trout in poor condition sometimes actually does not weigh more than half what he would when fat and in his best condition. This is a great difference, it is true, but it is a fact. It is said by medical authorities that a man cannot lose over three eighths of his weight and live. It is not so with a trout ; he can lose full fifty per cent and live. SECTION II. — THE COMMISSARY DEPARTMENT. The question of food for trout is a very important one, and I think, as a general thing, a very simple one tioning three, caught in September, 1867, by the subscriber at the outlet of Rangeley Lake, Franklin County, Maine, — this lake being the head-waters of the Androscoggin River : — One 10 Ibs. male, One 9! Ibs. do., One 8£ Ibs. female. The first and last were transported alive in a box of water, aerated by an air-pump, to my pond in Stanley, Morris County, N. J., but afterwards died in consequence of too high a tempera- ture in the water. The first weighed ten (10) Ibs. by steelyard within a half-hour after death. It is now in a glass case in my office in New York. The 93 Ibs. trout was sent to General Grant. Two of the trout from these waters I have sent to Professor Agassiz, in 1863 and in 1867, and in a personal interview he pro- nounced them real Brook Trout (Salmo fontinalis). Faithfully yours, GEO. SHEPARD PAGE, Pres't Oquossoc Ang. Ass. GROWING THE LARGE TROUT. 22Q too, though some printed remarks on the subject have made it appear complicated. The one correct thing to feed trout on,* as a rule, is the heart, liver, and lungs of animals killed for market. These combine the three desired points of trout food. They are cheap, accessible, and nutritious. They are cheap, averaging in the country about three cents a pound. It is true that liver in thickly settled places costs ten cents per pound, and if you should feed the trout entirely on liver in those places it would be very expensive feeding. But the lungs are quite as good food for trout as liver, and better in some respects. The lungs can be bought in any community for two cents a pound. Sheep's and lambs' plucks can also be bought for the same. As a general thing, in the more thickly settled places the lungs and sheep's plucks are cheaper than in the country, because of the greater number of animals killed in such localities. While food can be bought at these figures, trout can be profit- ably raised at half the present market-prices. This kind of food is accessible. Wherever there is a community of any size, cattle and sheep are killed for its support, and wherever these are killed the plucks may be procured. This class of food can al- ways be obtained also at the great cattle markets, like * Since writing the above a new kind of food has been used with great success at the Cold Spring Trout Ponds, viz., English Dog Biscuit. It can be obtained of Mr. Francis O. de Luce, 18 South William Street, New York. It costs ten cents a pound, and has many advantages over meat, particularly in being cleaner and in not spoiling quickly, as meat does. I recommend its use to all trout raisers. 23O DOMESTICATED TROUT. Brighton and Cambridge in Massachusetts, where it can be bought so low, that, with a hundred miles' ex- press-charges added, it will not cost over the average price in the country of three cents a pound. This food is nutritious. The plucks of animals, be- ing solid fresh meat, are the most nutritious food in the world for trout, and cannot be objectionable in this respect. This food, I should say, then, should form the chief reliance of the trout-grower. To prepare it for the fish, run it raw through a common sausage-grinder, and it is then ready to feed to them. Various other things can be used for food, and the best among these are : — 1. Other kinds of meat. 2. Live minnows. 3. Fish-flesh ground up. 4. Sour-milk curd. 5. Worms ancf insects. 1. Other kinds of meat. Trout, being carnivorous, will always thrive on meat. Therefore, any kind of meat, whether raw or boiled, which is cheap enough and convenient enough, makes suitable food for them. Horse-flesh,* young calves, and scant sheep would an- swer for trout-food, and are also cheap. 2. Live minnows. These unquestionably form a very desirable article of food for trout, and should be given them when they can be afforded. They are natu- ral food, and at the same time furnish a wholesome change from the usual meat diet. In some favorable * Paris lived on horse-flesh ; why should not trout ? GROWING THE LARGE TROUT. 23! places they can be obtained in vast quantities, and are the cheapest food that can be had. These are excep- tional localities, it is true ; but in almost all brooks they can be collected in considerable quantities by shutting off the stream above, and netting them out of the little pools in which they are trapped by the receding water. The use of live minnows in large ponds has been objected to on the ground that minnows, living on the same insects and other food as the trout, rob the trout of what they would otherwise get themselves. This objection has some weight, it is true, in itself; but it is more than offset by the value of the min- nows to the trout. The minnows more than com- pensate in themselves to the trout for what they eat. I would give the trout all the minnows I could get. There is another objection which deserves more consideration, and this is that in amateur trout ponds, where large and small trout are kept together without sorting, the habit of feeding on minnows may encour- age the bad habit, in the trout, of feeding on each other. In this case I would take a day or two for the work, and sort the fish thoroughly, and then let them have the minnows ; but if this cannot be done, per- haps the objection against the minnows holds good. 3. Fish-flesh ground up. This is undoubtedly good food for trout, and in some districts fish are so plenty that it is the cheapest and most accessible food. For instance, on the Mirimichi River, where smelts are used to manure the land, or on the Missisquoi, where a large sturgeon can be bought for a dollar, and perch for 232 DOMESTICATED TROUT. nothing, these or other fish, killed and run through a mill such as is used for grinding mackerel bait, would answer quite as well as meat. Trout like meat best, but thrive well on fish food. 4. Sour-milk curd. This makes very good food for trout, though they do not like it as well as meat. It is easily prepared by pouring boiling water on bonny-clabber and straining out the whey. What re- mains in the strainer is the curd. When milk is plenty, this food is very accessible, and also not ex- pensive, and makes a very good occasional substitute for meat ; but an exclusive diet of curd is thought to be unhealthful. 5. Worms and insects. These, of course, with all other natural food, are good for the trout. Give them all you can get, which, after all, will not be much, com- pared with the rest of their food, if you have many trout. You can, however, breed maggots for them in considerable numbers by hanging the meat over the ponds and letting the flies work in it. This is called a maggot factory, and, though a good food-producer, especially for yearlings, is to my mind very objection- able about a domestic trout pond. If you have, a pond at a distance which you seldom visit, a maggot factory will do very well ; but where you go every day, it is a nuisance. If you do use one anywhere, contrive to cover the meat with a box. This softens the objec- tionableness of it somewhat. A few words more should be added here about the care and preparation of the meat, where trout breeding is practised on a large scale. At a trout breeding GROWING THE LARGE TROUT. 233 establishment in full operation there are three distinct sets of fish, the young fry, the yearlings, and the large trout, and there should be a dog. These three sets of trout require three different preparations of -meat. For the young fry the liver is used, and is prepared by grating it on a cheese-grater, as described in the chap- ter on young fry. For the yearlings the heart is used, and is cut up in a meat-cutter, which will cut it finer than the sausage-grinder. For the large trout the meat that is left is run through the sausage-grinder, except the coarser parts, which are given to the dog. The heart is used for the yearlings, simply because it will cut up better in the cutter.* Starret's American Chopping Machine. When, therefore, the meat is brought to the ponds, it is first sorted ; the liver is cut off and laid aside for * The cutter used at the Cold Spring Trout Ponds is Star- ret's American Chopping Machine, and the sausage-grinder is Perry's Patent No. 4. Both answer their purpose very weiL 234 DOMESTICATED TROUT. the young fish, the best part of the heart is cut off for the yearlings, the coarser pieces are saved for the dog, and the rest is run through the grinder for the large fish. This systematizes the whole thing, and disposes of all the meat. In the spring and fall you will have no trouble in keeping the meat ; but in the summer and winter it is different. The meat freezes solid in winter, and spoils quickly in summer, and in the exceedingly hot weather it is sometimes very troublesome. Your great protec- tion against these evils lies in the spring water. Keep the meat in the cold spring water, and it will not spoil in the summer within a reasonable time, nor freeze in the winter. It is true that remaining under water does not improve its quality ; but the other advantages are more than sufficient, at extreme temperatures, to offset this objection. Do not feed spoiled meat to the fish. If you ever have any on hand, bury it in some place set apart for that purpose.* The trout feed differently at different seasons of the year. In the spring, when the water begins to warm up, they are most voracious, and will eat a larger daily allowance for their weight than at any other part of the year. During the first half of the summer their appetite does not diminish much, except when the wa- ter gets heated. When this occurs, they do not care so much for food. Mr. Ainsworth found that his trout in New York stopped eating at 70°. Mine continue to take food up to 75°. Above that they are more or * This place at the Cold Spring Trout Ponds has been nick- named the "Potter's Field." GROWING THE LARGE TROUT. 235 less indifferent to it. As the spawning season ap- proaches, the trout care less and less for food, and just at their spawning time, and a week or two previous, they avoid it, and go without eating entirely. When their spawning is over they eat again, and are quite ravenous on warm days, and where the temperature of the water does not alter much they feed well all winter ; but in brooks or ponds where the water cools with the season their appetite falls off, and when the water drops to 36°, or less, they either scarcely notice the food or take it very languidly. At this degree of cold they are in a torpid condition, and there is about as much difference between their spring and elasticity at this time and in the summer, as there is between the movements of a mud-turtle and a Scotch terrier after rats. On mild days in winter when the sun warms the water, or after a warm rain, they will wake up from their lethargy and eat as they do in summer. These are the times when they will indulge their cannibal instincts if they are not fed, and you should be prompt on such days to anticipate their unusual appetite with proper food. Trout feed differently at different times in the day. In the winter the favorable time is the warmest part of the day. In summer they take their food best about sundown ; they are very lively then both in the spring and summer, and will leap out of the water and lash the surface with their tails in a way that is very exhilarating to see. When the keeper approaches to feed them, they will come towards him, or will collect in their accustomed 236 DOMESTICATED TROUT. place of eating, if they have not been disturbed ; but if they have been molested they will fly about in all directions, stir up the gravel, reject their food, and act as if they were crazy. This is a bad sign, and when you see it you may know that it means that they have been molested and frightened during the night, prob- ably by minks, herons, or men. Once a day is sufficiently often to feed the large trout. They will keep fat and grow rapidly on one feed a day; but I think they would grow somewhat better if fed oftener and less at a time. There is not much danger of their eating too much. Feed till they decline the food, then stop. They will sometimes take too large pieces, and so choke themselves to death, and they will perhaps eat enough in the excitement of feeding time to feel uncomfortably afterwards ; but they are usually not gluttons enough to gorge them- selves to a fatal repletion. Experience will teach the trout grower how much to feed daily to a given number of trout. This quantity varies with the season, the quality, the quantity, and temperature of the water, and other circumstances, and cannot be stated definitely. Green says five pounds of meat a day for a thousand three-year-olds, three pounds for a thousand two-year-olds. I should say this would be an average feed through the year, but in summer my two-year-olds and three-year-olds eat much more. I think it is safe to say that under favorable circumstances large trout of any age will eat one fiftieth of their weight in the summer, that one per cent of their weight a day will keep them in good GROWING THE LARGE TROUT. 237 condition through the year, and that they would do very well on half that allowance. I have also ob- served that with two-year-olds and three-year-olds five pounds of meat food is an equivalent for one pound of trout growth. SECTION III. — How TO SECURE THE LARGE TROUT AGAINST LOSS. There is no domesticated creature in the world that can be kept with so little loss as large trout, if care- fully protected. Indeed, the loss is almost nothing. The large trout keep healthy and vigorous at all sea- sons, and very rarely die if properly cared for ; though if they are carelessly exposed they will waste away like dew before the sun. If you observe the following di- rections, many of which are only repetitions of what has been previously said, I think your trout will be safe : — 1. Guard against freshets. 2. Avoid overstocking. 3. Guard against heated water. 4. Handle carefully. 5. Keep the trout well sorted. 6. Never let the water get foul. 7. Protect from natural enemies. 8. Protect from poachers. i. Guard against freshets. So much has been said under this head in the chapter on suitable water, that we will merely refer the reader to that chapter, saying, en passant, that the danger from this source cannot be overestimated, and that the losses, when they do oc- cur, are usually overwhelming. 238 DOMESTICATED TROUT. 2. Avoid overstocking. There is no indiscretion in the world so easy for a trout breeder to fall into as overstocking his ponds when he has many fish and not much water*; but I need not say it is a fatal mistake. There is usually a very dry hot time in the summer, which, if not a fiery furnace, is, at least, a watery fur- nace for the trout to pass through ; and it is often hard in the fall, winter, or spring, when the deceitful water is cold, and there is plenty of it, to realize what the inexorable exactions of this ordeal will be ; and al- most without knowing it the trout breeder will some- times get more trout into his stream than it will carry through the summer. Therefore the beginner cannot too carefully impress on his mind the simple truism that no stream can be relied on for more than what it will do in the hottest and dryest day of the hottest and dryest season of the year, and this principle should be acted upon. If, however, you ever happen to have on hand more than you know you can sum- mer in your stream, there is a very simple way to get over the difficulty, and one which I have often re- sorted to, namely, to turn some of the trout out to pasture through the dry time. I mean by this to carry them off to some neighboring brook where you have provided a temporary enclosure for them through the dangerous crisis ; this is not a difficult matter, and if you want the spawn from them in the fall it is expedient to do it, taking the precaution to remove them on cool mornings when the transporta- tion and handling will not be likely to hurt them. * See remarks on water supply and droughts, pp. 11-12. GROWING THE LARGE TROUT. 239 If you have too many on hand in the spring, and have no means of pasturing them, then kill and sell them for what you can get while they are in good con- dition ; it is better than to have them die of the heat. If you know of no one that wants them, then pack them in ice, and consign them to some good firm in Fulton Fish Market, New York City, to sell on com- mission. Fresh brook trout are always in demand there. But if the dry time comes suddenly, and you are caught with too many trout on hand and a short supply of water, you have two remedies. One is to use ice ; if you are not in a very bad predicament, a moderate quantity of ice, used three hours a day, — the hot interval between i p. M. and 4 p. M. being the worst time for the water, — will often save them. The other remedy is to reservoir part of the water in the stream above the trout during the cool of the night, and let it on by degrees in the hottest part of the day; this will answer to some extent, when the days only are hot. But if the heat and drought are extreme and long continued, and nights and days are both hot, then neither ice nor reserves of water will save your trout in an overstocked pond, and you must lose them. I will merely add that a plethoric condition of the fish, and an uncleanly pond, increase very much the dangers of the dry season. 3. Guard against heated water. This point is some- what related to the last, inasmuch as the water is usu- ally the hottest at the dryest time, and the warmer it is the less stock it will keep. But there is also danger of the water heating up enough to kill the fish, even 24O DOMESTICATED TROUT. when there is plenty of it and the season is not par- ticularly dry. This point has also been discussed on page 12, to which the reader is referred. I will re- peat here that the extreme limit of danger is variable, depending upon the quantity, quality, and rapidity of the water, and also upon the degree of exposure to the sun, and the condition of the fish. The trout exhibited by the writer at the Mechanics' Fair, at Boston, in 1869, appeared easy with a medium supply of water at 68°. At 70° they were a little dis- tressed, at 73° much distressed, and breathing at the rate of 100 times a minute. Mr. Stephen H. Ainsworth, in a letter to the writer, says that 68° is the highest temperature that his trout do well in, at 70° they stop eating, at 75° begin to die, at 80° die faster, and at 90° all die. Seth Green's book says that trout will die at 68°.* This may be the case in New York, but it is not so in New England. Trout in our vigorous swift running water will sometimes live through 75°. Still I consider 75° very dangerous, and anything over 70° unsafe. There is no remedy for the water heating up, except artificial cooling. If you have ice enough, you can do something in that direction in a small stream as long as the ice lasts ; but it is a forlorn hope. However, if you find the water heating to a fatal extent, and think it worth while to try to save them with ice, first diminish their rations or stop them altogether, make the current as swift as possible, and then do what you can with ice. You will probably save some, if the heated term does not last too long. But if your brook * Trout Culture, p. 52. GROWING THE LARGE TROUT. 24! heats up so as to require the application of ice, in any but very exceptional instances I should say select another place for your operations. Ice may save the fish, but it is paying too dear for the whistle, and it is coming a little too near danger to be desirable. 4. Handle the fish carefully. Handle the fish care- fully when you have occasion to handle them at all, which will not be often, except in sorting, in moving from one pond to another, and in spawning. It makes a great difference in handling and carrying trout whether it is hot or cold weather. In winter you can do almost anything with them, short of using actual violence, without killing them ; but in very hot weather in summer, when they are fat and the water is warm, they actually seem to die before they are hurt. Rough handling is very often the cause of death ; but it is a very unnecessary and inexcusable cause. All the handling that needs to be done can, ninety-nine times in a hundred, be done without hurting the fish. The suggestions given in the chapter on spawning trout will perhaps be a sufficient guide on this point. I would by all means dissect at least one fish, and find where the vitals lie, and just how the viscera are packed together inside. You will find you can, by practice, squeeze a fish very hard, if you know where the vitals are, without killing it. Always be careful not to scrape off the slime from the skin, for where the slime is off fungus will grow, and the result is death. 5. Keep your trout well sorted. I know that it is often said, " Feed your trout well, and they will not eat 242 DOMESTICATED TROUT. each other." Perhaps they will not, but it is not pru- dent to trust them. It is a risk, to say the least of it, to keep fish of different sizes in a herd together, and, being a risk, it ought to be avoided on principle. If any one doubts whether actual mischief is done by it, let him put five hundred trout of different sizes in a pond for a year, and take them out at the end of that time and count them over again. I think he will be convinced. This is something that some trout growers are altogether too careless about. They would not think of keeping foxes and fowls together, even if the foxes were well fed, yet they run equal risk with their trout, and think nothing of it. I have seen more than one trout pond where it was only a question of time about one half of the fish going down the throats of the other half. The fact is, trout are by nature incurable cannibals, and they will always gratify their natural in- stincts, to some extent at least, and will sometimes carry them to a very destructive length.* My advice is, where you have different-sized trout confined, to draw off your pond, or, if you cannot draw * I once had some full-grown trout, of the peculiarly large va- riety found in Monadnoc Lake, confined in a small pond, and one autumn had occasion to remove them, and put in a number of small brook trout The pond was a covered one, and the fish were not particularly examined through the winter. In the spring, when the cover was removed, it was found that more than one half of the brook trout had disappeared. A thorough search of the pond revealed a large and very fat Monadnoc trout hidden in a dark hole, where he had been overlooked in the removal of the others. He had eaten at least one hundred two or three ounce trout during the winter. GROWING THE LARGE TROUT. 243 it off, sweep out all the fish with a sweep seine, and sort them thoroughly at stated intervals. In sorting, it is well to remember that there is six times as much mischief from having one large one with six small ones than six large ones with one small one, because the one large one will eat up all the small ones, while the whole of the other six can eat only the small one. The most dangerous times, when the trout are not kept sorted, are just after a rain in the spring or summer, and when the weather suddenly moderates in the win- ter. In the first case the disturbed water prevents their taking their regular feed, and they get very hun- gry in consequence, and in the other case the warm winter days sharpen their appetites. In either case, if you do not anticipate the cravings of their instincts with your food, the smaller trout will pay the penalty of their lives. It makes no difference with the large ones whether they can wholly swallow those they kill or not. They seize them by the middle, whirl them round as herons do, and swallow them head down. If they cannot swallow the whole fish at first, they will begin digesting the end that is down, and swallow the rest as it comes along. I will also suggest the following precaution here, though it is a little out of place. If you have two ponds on the same brook, one below the other, with large fish in one and small fish in the other, make it doubly sure that none of the large ones can by any possibility escape into the pond of smaller ones. Do not be satisfied with leaving things so that you think this cannot happen, but make it impossible by any 244 DOMESTICATED TROUT. mishap short of an earthquake, for the possible conse- quences cannot be exaggerated ; and what makes it all the worse is that, should a large trout get among the small ones, and adopt cannibal habits, he would keep himself completely hidden, — such is the habit of can- nibal fish, — and you might not discover him till his ravages had been very disastrous. Fix your ponds, therefore, so that no freshet, or clogging up of the screens, or other contingency, can make it possible for the large ones to jump over, creep under, or in any other way get into the pond of small ones. 6. Never let the water get foul. The source of foul- ness in the water, whenever it occurs, is, of course, the feed which falls to the bottom of the pond and the effete matter coming from the fish. If these accumu- late in any great quantity, danger is imminent. The fish are, so to speak, on the edge of a precipice, and the first warm day may bring great loss. There is but one remedy for a foul pond, except re- moving the fish and digging it out anew, and that is the use of earth. This remedy, though the only one, is a sure one. Earth, as is now well known, is a won- derful absorbent of foul gases. Therefore, when the bed of your pond gets foul, and it is not convenient to clean it out, throw in a layer of three inches, or, if very foul, of six inches of common earth. This will make the pond as sweet and clean as it ever was, and the fish, too, will be better for it. Do not be afraid of muddying the water. Muddy water never killed a trout yet, though thousands have died for the want of it. GROWING THE LARGE TROUT. 245 Beginners are here cautioned against drawing down the pond, when it gets foul, in order to remove the fish, for this is the very surest thing to make matters worse. The water becomes thick with the offending matter, when the pond is drawn off, and it will cer- tainly sicken the fish and check their growth, if it does not kill them outright. It is not so dangerous with large trout as with young fry, thousands of which have been killed by this practice ; but it is bad enough with fish of any size, and never ought to be resorted to. It is a good plan to keep a few moderate-sized suckers or mullets (Catostomi) — mullets are the hand- somer fish — in your ponds for scavengers. They do good service at this work, they are perfectly harmless, and will clean the bottom of the pond of whatever food escapes the mouths of the trout. Every trout pond, I think, should contain one or more of them. 7. Protect from natural enemies. The natural ene- mies of large trout in New England are herons, fish hawks, and minks. Kingfishers are also very destruc- tive to yearlings, and will kill two-year-olds, if they do not eat them. Snakes also prey on yearlings, and will sometimes swallow a two-year-old ; but these two latter enemies are chiefly formidable to yearlings. The best protection against the birds is to cover the pond. A plain rack, made of inch-strips of pine, laid about two inches apart, answers very well for this pur- pose. The birds will not go through the slats for the fish. The rafts which are put on the pond to shade it are some protection against birds, especially king- fishers ; but herons will stand on the rafts themselves, 246 DOMESTICATED TROUT. and with their long necks reach the incautious trout in their hiding-places underneath. Herons have very capacious throats, a passion for fish, and a rapid diges- tion. They are consequently very much to be dreaded. They do their mischief evenings and mornings, but mostly in the early morning ; and as they are not very wary birds, you can usually shoot them, if you get up early enough. They are waders, also, and, having very long feet, they are easily caught alive, by setting traps in the mud where their foot-tracks have been discovered. I once caught a large blue heron so, with five two-year-old trout in his throat. If you get one alive, and are at all incredulous about their trout- destroying capacity, keep him till he is hungry, and then give him a panful of live minnows to eat. He will soon show what herons can do in stowing away fish, and will remove, I think, all scepticism from your mind henceforth about the destructiveriess of herons among trout. The kingfishers are easily shot. They generally come early in the morning, or about three hours before sundown ; but, if not molested, they will stay around all day, and increase in numbers very fast. Approach them with a gun, if you can. If you are not able to get within gunshot, lie in wait for them near one of their favorite perches about the ponds, and they will usually soon come within gunshot of their own accord. You can also trap them, by erecting a tall pole over the pond, and, setting a steel trap or bird-trap on the top of it ; it will not be long before the kingfisher will alight on the pole to watch for his prey, and will be caught. The same trick answers for GROWING THE LARGE TROUT. 247 hawks. Minks are not so easy to manage. The best chance is to trap them on their way to the ponds in the fall, as that is the time when they make their way up the brooks. Green's method of trapping minks, which is the best I know of, is as follows : " Make a box eighteen inches long by six inches broad and deep, leaving one end open. Set a com- mon game-trap (such as is used for catching muskrats) in the open end of the box, in such a position that when the jaws are closed they will be in a line with the length of the trap. If it is set crossways it will be apt to throw the mink out, instead of catching it. Put the bait in the further end of the box (a piece of meat or a dead fish will answer for bait), set the trap, and cover it over with a large leaf. Now there is only one way for the mink to get at the bait, which is by walk- ing over the trap." You will be very likely to catch the mink in this way, though you will probably get a few house cats first. When minks begin to infest your waters, you will see the advantage of plank ponds over earth ponds ; for in plank ponds the minks can- not hide permanently, but must come and go every time they make a meal off the fish. On the contrary, in the earth ponds they will find some old muskrat- hole or other place where they will probably take up winter quarters ; and when the ground is frozen solid for a foot or two below the surface it will be found very hard to dislodge them. It is almost im- possible to trap them then, for two reasons. In the first place, as they have a subterranean passage to their daily food they seldom appear above ground, 248 DOMESTICATED TROUT. where they can be caught or shot ; and, secondly, hav- ing plenty of the food which they like best, namely, live trout, you have nothing better to tempt them into a trap with. Your only chance is this. Place a dry plank on the north side of the pond, so that one end rests in the water and the other slants some ways up the bank. Put a steel trap on the plank, near the lower end, and fasten it so that the mink, if caught, will throw it into the water. Minks like to sun them- selves in the winter, and though your intrenched ene- my will not be baited into a trap, he will sometimes step into one in trying to get to a dry spot in the sun. If minks are so troublesome as to warrant the outlay, enclose the pond on all sides and on the top so tightly that a mink cannot get in ; then you are safe. There is no way to manage the snakes but to kill them ; but they are not so very destructive to large trout ; and, if you keep off all other enemies, I do not think you will suffer much from snakes. POACHERS. I know the prevailing opinion is now that there is not much danger from poachers. I wish to lift up my voice against this delusion. Your trout in an exposed pond are just about as safe as your money would be in it ; indeed, in some respects, not so safe, for there are people who will steal trout who would not steal money. Yet persons will lock up their money in vaults in banks, and then not feel safe, and will leave a hun- dred or a thousand dollars' worth of trout in an un- protected pond and think there is not much risk. It GROWING THE LARGE TROUT, 249 is a great mistake. I would throw every barrier I possibly could between my trout and trout-thieves, and would make my ponds just as secure from poacher raids as the value of their contents will warrant Poachers are of three classes. First, the regular thief. He steals the trout the same as he steals his firewood and poultry, because he prefers to get his living that way. He comes regularly, but, with a thief's caution, by the least suspected path, and usually takes just enough each time not to have them missed. A year's steady work at it, however, will leave its marks on your trout stock, you may depend. Possibly the role will be changed some time, and all your trout be taken off in one night and shipped to market and sold. It is of no use to say that the law will keep this kind off. The law has no effect on them. They make a business of breaking the .law, and if it does not keep them from other property it will not keep them from trout. The second class of poachers are those who steal the fish partly for the lark of it, and partly because they want the fish, and have not enough principle to care whether it is right or wrong. The law restrains these somewhat, and makes their visits scarcer, but does not keep them off entirely. The third class are those who have principle enough not to steal other things, but seem to have such a passion for trout fishing that a stocked trout pond is a temptation they cannot resist. I will only say of these, that the sight of their names in print would be a start- ling revelation of what otherwise respectable persons can be sometimes tempted into doing. 25O DOMESTICATED TROUT. With these three classes of poachers about, your trout are never secure. So I would say, make the safety of your ponds just as near a certainty as you can. Do not trust to people's being too honest, or too indo- lent, or too unenterprising to take your trout, for there are dishonesty, cunning, and enterprise enough in the world to steal them twenty times over, and it is more than likely that these qualities exist in the very neighborhood of your ponds. The true plan is to put temptation out of the way of all by interposing impassable barriers between the trout and the thieves ; and as a guide to what may be done, I will give a brief description of the safeguards employed at the Cold Spring Trout Ponds. There is, first, an admis- sion-fee to the grounds, and visitors are required to register their names. This has a good effect in vari- ous ways. It keeps the crowd unfamiliar with the temptation, which is a good deal ; for persons who have never seen the trout in the daytime are much less likely to come for them at night than those who have seen them often. Poachers might say of trout what Pope said of vice, — When " seen too oft, familiar with its face, We first endure, then pity, then embrace." An admittance fee also makes the number of visi- tors so small that any suspicious persons taking obser- vations for a midnight raid are likely to be noticed. At all events, it makes you feel safer than if there were people around your ponds all day that you did not know anything about. Finally, if a fee is objec- tionable to your taste, you need not take it any oftener GROWING THE LARGE TROUT. than you like. Giving notice that one is charged will answer the purpose. Secondly, a copy of the statute in regard to poach- ing is placed where all can read it. This has a good effect, for a quiet contemplation of six months' im- prisonment, as the penalty is in New Hampshire, or $ 100 fine, as it is in some other places, is a serious damper on the ardor of at least some minds possessed of poaching proclivities. Thirdly, a tight board fence eight feet high (and it should be higher), closely spiked at the top, surrounds the ponds of large trout. This, it is true, will not prevent a resolute thief from climbing over and getting the fish, if he has made up his mind that he will have them, but it nevertheless reduces the number very much of the dangerous ones, and limits them to the very enterprising only. There are a hundred poachers who will steal up and throw their lines into an open pond, where there is one who will bring a ladder and scale a spiked fence and descend on the other side, where he does not know how many spring guns, or bull- dogs, or what not, there may be inside to receive him. A spiked enclosure lessens the chances of loss by poaching very much. Fourthly, there is at the Cold Spring Trout Ponds a dog whose ferocity I have never seen surpassed except in a chained tiger (one of Van Amburgh's) at a menagerie I once visited, and who is as stanch and as incorruptible as he is ferocious. This dog " Jack " is the last thing in the world a poacher would like to encounter in a spiked enclosure, and adds very 252 DOMESTICATED TROUT. much, I think, to the safety of the fish. He is cer- tainly a terror to all who know him. It is true a watch- dog can be shot or poisoned, and so be got out of the "Jack" way ; but he is at least another barrier to danger, and as long as he lives, at all events, he is a protection. There are other safeguards inside of the fence which are disclosed only to the poachers themselves, but which make the way of the transgressor exceedingly perilous. I would add here that the racks which are put over the ponds to keep off the birds are also a protection against a line being thrown over the fence among the trout. But for all the protection of these GROWING THE LARGE TROUT. 253 • safeguards there is one better than all, and that is to have your dwelling-house or your keeper's house either over or close to the ponds. Then with a dog that will give the alarm at the approach of danger you may consider your trout as near safe as the nature of the case permits. SECTION IV. — ADULT TROUT. — How TO GROW TROUT TO A VERY LARGE SlZE, AND RAPIDLY. Trout show their keeping as well as any other crea- ture, and more than most. I have seen a trout that was reasonably believed to be but two years old that weighed a pound, and I have seen one of the same age that barely turned the scales at half an ounce. The larger one had been in a warm stream which swarmed with blood-suckers, than which there is no more growing food in the world for trout. The other happened to be confined in a small enclosure of very cold water, almost destitute of food. These instances show what a difference unlike conditions will make in the growth of a trout. You can grow them at an almost incredible rate, or you can dwarf them to an almost incredible degree. If you want to dwarf trout, keep them in cold sun- less water, in close confinement, and with little food, and you will do it. If you want to grow them fast and large, observe the following directions : — = i. Give them plenty of water. Of two similar lots of trout confined in the same amount of space and kept on the same amount of food, those which have the largest supply of water will grow the best. 254 DOMESTICATED TROUT. 2. Give them plenty of food. Trout will not grow in exact proportion to the food which is given them, because their growth is modified by so many other conditions ; but you may be sure of this, that the more you feed them, and the more often, under any conditions, the better they will grow. 3. Keep them where the water warms up in the summer, say to 65° or nearly 70°. You cannot grow trout fast or large in very cold water. Feed them and care for them the best you can, they must, neverthe- less, have comparatively warm water ; and in such water, with plenty of food, range, and space, their rate of growth is simply wonderful. 4. Give them range. If you want to grow your trout very large, you must give them range. I say if you want to grow them very large. Range is not neces- sary, by any means, to the average growth of trout, for they will grow to a very good size in small places, and it is also generally incompatible with trout growing as a business to give them great range ; but, if you want to raise the very largest trout, you must give them the very largest range. Trout will not grow beyond a cer- tain size in confinement. They will stop or nearly stop growing when they have reached a certain limit. Range also influences the rate of growth. Large ponds grow trout faster, as a rule, than small ponds. Put ten trout into a pool three feet square, and ten others in a pond three rods square, and those in the pond will grow very much faster than those in the pool, on the same food. In a pond of three acres they would grow faster yet. GROWING THE LARGE TROUT. 255 5. Give them plenty of space. I mean by space the amount of cubic feet of room to each fish in a pond. This, of course, is not synonymous with range. As, for instance, a thousand head of cattle in a pasture would have as much range as ten head, but ten head confined in it alone would have a hundred times the space. Space is something which cannot be afforded by trout growers generally, but it is necessary to the very large and rapid growth of trout. Put one thou- sand trout in a pond twenty feet square, and ten trout in another pond of the same size, and keep both lots on the same food, and you will be astonished to see how much the growth of the smaller lot exceeds that of the larger lot. Much space is not necessary to keep trout alive in and doing well, but it is neverthe- less indispensable to very large growth. The suggestions of this chapter are intended more for amateurs and those who wish to experiment on raising very large trout than for those who make a busi- ness of trout raising ; for though the raising of very large trout is a desirable thing always, it is not often consistent with the best economy, — smaller trout and more of them, with perfect security, being a more profit- able end to seek. SECTION V. — DAILY CARE OF THE LARGE TROUT. The mere daily care of the large trout is almost nothing, if the arrangements for keeping them are right to begin with. I know of no domesticated crea- ture which requires so little daily care. With the ex- ception of feeding them once a day, and keeping the 256 DOMESTICATED TROUT. inlets and outlets clear, you need not bestow a thought on them for weeks. They do not require daily groom- ing like a horse, or daily milking like a cow, or careful housing in winter like sheep, or watching like poultry. If you have made the ponds safe from the changes of weather and the attacks of enemies, the trout will be, summer and winter, their own keepers, with your as- sistance once a day in giving them their food, and twice a year in sorting them. They can even be kept without eating for several days without the injurious results which would follow similar neglect with other domesticated creatures. There is also seldom or never any sickness among large trout kept in suitable waters. This is a very striking feature of trout growing, and a very favorable one. It is astonishing how many you can keep in a pond of good water the year round without danger of sickness or loss by death. Fowls confined in numbers get sick and die. Disease breaks out and spreads among large flocks of sheep and herds of cattle when confined, but you can keep thousands of trout in a very small enclosure of good water in per- fect health all the year round. Indeed, there is no other creature above the grade of insects, except other fish, that you can keep in such large numbers and in so small a space with so little risk of disease and death. This is one of the most remarkable points about growing the large trout, and reduces the labor of taking care of them to a minimum. To be sure, the general work connected with keeping the large trout is very considerable, such as taking the eggs, prepar- ing the spawning-beds, and the like; but the mere daily care of the fish themselves is very trifling. GROWING THE LARGE TROUT. 257 SECTION VI. — MARKETING THE LARGE TROUT. Marketing the trout is a simple process. You take a pail, some small pieces of ice, a little food, and a hard-wood stick about a foot long, or a piece of iron, to kill the trout with, and go to the pond. Place a large tub near where you are going to take out the fish, fill it half full of water, throw a little food into the pond, and, when the fish come for it, take out a netful, and empty them into the tub. Sort out what fish you want to kill, and throw back the rest, then, lifting the fish up one by one with the left hand, strike a sharp blow on the top of the skull with the instrument in the right. This will kill them at once, which is an impor- tant point gained. Put the dead ones immediately with the ice in the pail, and take them to the scales to weigh them. Having noted down their weight, pack them in a box of pounded ice and sawdust, nail up the box, label it, and send it to the express-office. In filling a twenty-pound order, this can be done so quickly that the trout can be on their way within half an hour after you go to the ponds for them, and they need not have been exposed to the air (without ice) three minutes in all. Killed and packed in this way, they will open twenty-four hours afterwards as fresh and hard as when they were taken out of the ponds, and will be a great deal harder than trout caught by fishermen in the wild brooks the same morning. The proprietor of the Parker House at Boston, to whom I have furnished trout for several years, said that the Cold Spring Trout, which were killed and packed in 258 DOMESTICATED TROUT. this way, came the best of any they had ever had in the house. Yet his house is one hundred and twenty miles from the ponds. The best time to kill fish for the table is, as a rule, that season of the year which is the antipodes of the spawning season. The best time, therefore, to begin to market trout is in the spring, just after their spring appetite comes on. They are then hard and plump, and in first-rate condition. From then till July they do very well to market. After that they steadily de- teriorate. As the spawning season approaches, their flesh weighs less compared with their size. They gain very much in weight between April ist and July ist, sometimes fifty per cent and .over, which makes it desirable on that account to hold them till July. On the other hand, the prices are best at the beginning of the season, and fall very considerably by July. My trout, sent to Fulton Market, New York, and sold on commission, April i, 1871, brought $ 1.25 per pound. Before the month was out the price had fallen to 90 cents. The question as to the age at which it is most profit- able to market trout is an important one. .1 think that it is the spring of the fourth or fifth year. It cannot be earlier than this, for the trout get some of their best, if not their very best, growth the third year, and to kill them before they are three years old would cut off nearly all the increase from them. There are also reasons why they are most profitably killed before they are older than four years. The ratio of their growth to the cost of keeping has then GROWING THE LARGE TROUT. 259 reached its maximum, at least in small artificial ponds, and is on the wane. Every year after that they are kept also increases the general risk. They are at this age of the best marketable size, — very large trout not being as salable as pound-trout or less. This question, however, of the most profitable age to market the fish varies with circumstances, and it is one which every trout breeder will doubtless best settle for himself, though the above suggestions may perhaps, in some measure, serve as a guide. The New York market is the best market in the country for first-class trout, as it is for game of every description. The Boston market falls very much be- low it, and most of the smaller cities are very poor places indeed to which to send trout for sale in the public markets. CHAPTER VI. CONCLUDING CHAPTER. SECTION I. — THE WORK IN GENERAL AT A TROUT- BREEDING ESTABLISHMENT. THE work at a trout-breeding establishment varies with the season of the year. In the summer, when the work is the lightest, it is a routine nearly as fol- lows. You go to the ponds in the morning, examine the streams,* and clean the screens. You then take the meat as the butcher has left it, sort it for the different sizes of fish, grate the liver for the young fry, chop the heart in the cutter for the yearlings, run the rest through the sausage-grinder for the large trout, and give the refuse to the dog. You next take the feeder and feed the fry, and examine them thoroughly ; then the yearlings, then the large fish. You then feed the * I would like here to caution beginners, when going the rounds for the purpose of seeing if everything is right, never to take anything for granted, but, on the contrary, to look over the works with the expectation of finding something wrong. Though you may have left everything perfectly safe, as you supposed, the day before, a dozen things may have occurred during the night to make trouble. I could mention numberless instances where losses have occurred from the keeper taking for granted that everything was right, and consequently overlooking something that was wrong. CONCLUDING CHAPTER. 26 I young fry again, and if in spring water, give them earth twice a week. Set things in order, observe the progress of your experiments if you have any, see that everything is left right, and then, if no accident has happened, your work is done for the morning. In the afternoon you feed the young fry again twice and the yearlings once, leave things right for the night, and the work is done for the day, if it is a fair day. If it is a rainy day, the streams and screens will need more watching and care, and there will perhaps be1 gates and flash-boards to alter. You will also during the summer probably have some improvements to make, and some changing and sorting of the young fry, if you have many. As the spawning season approaches, there will be, among other things, in addition to the routine work, the spawning races to clear out and bed with clean gravel, the hatching troughs to clean out and prepare for use, new flannel filters to make, moss to get in for packing the eggs, traps to set, and special precautions to take against the fall freshets. After the spawning season begins, there will be the feeding, the spawning the fish, the laying down of the eggs, orders to fill, and the daily examination of the eggs. If you secure a good impregnation this latter job will not be much, but if you have poor luck im- pregnating, it will be a great burden all through the winter, increasing every day till long after the fish be- gin to hatch. After the hatching commences, and the empty eggs are all picked out, there is a lull in the work till the new fry begin to feed. It is then very 262 DOMESTICATED TROUT. cold. The old trout will need to be fed but three or four times a week, the yearlings not much oftener, the young fry only once or twice a day, and there will now be no more bad eggs to pick out. Thus the work is very much lessened ; but it is the lull before the storm, if this expression may be used, for soon the young fry begin to feed, and their thousands or hundreds of thousands of mouths must be fed five or six times a day. The shells of the hatched eggs, now be- ing constantly shed by the young fish, clog up the screens, and make incessant watching of them neces- sary. Very likely the frost and muskrats are making trou- ble with the ponds or aqueducts outside, and altogether this is usually made a very busy time, the burden of which is not at all lessened by the shortness of the days and the excessive cold. As the spring advances the young fry are thinned out by sales, they require to be fed less often, the fry of last year have become year- lings, the days lengthen, the weather grows warmer, and the work becomes easier and pleasanter, until the sales of the young fry are over. The balance of them are soon turned into their nurseries, rearing-boxes, or ponds, and the labor is reduced again to the mere rou- tine of the summer. The cares of a trout-breeding establishment in full operation are very considerable most of the time, and few beginners will be wholly able to free themselves from consequent anxiety ; but this is more than bal- anced a hundred times over by the constant interest and ever-increasing enthusiasm which the beautiful CONCLUDING CHAPTER. 263 creatures inspire at every stage of their growth. There is no time when they are not beautiful and intensely interesting, and it is not exaggerating to say that at some particular periods, as, for instance, the spawn- ing season, the first appearance of the embryo in the egg, and the hatching of the egg, afford to a lover of nature a most pleasurable excitement, which would seem to be satisfying even to those who think that it takes a good deal of excitement to satisfy them. On the whole, I should say that the work of a trout farm is attended with considerable care, and at first with some anxiety, but also with a corresponding in- terest and enjoyment, and not without a very consider- able degree of pleasurable excitement at times. THE PECUNIARY ASPECT OF TROUT CULTURE. One of the chief inquiries at the present time in re- gard to trout culture is whether it can be made a prof- itable business. In reply to this inquiry I have no hesitation in saying that I think trout breeding can be made profitable anywhere in the settled portions of this country where there is plenty of suitable water ; but to be very profitable it must be on a large scale. It will not pay great profits to raise a thousand trout a year, but a handsome income will be made from raising ten thousand a year. I find that the cost of growing trout is very small indeed, and that the returns are very large indeed. It costs no more to keep a thousand trout each, of the three different sizes, springlings, yearlings, and 264 DOMESTICATED TROUT. two-year-olds, than it does in the country to keep a horse, and what would keep a pair of horses at a sta- ble in the city would enable a man to turn out five thousand pound of trout a year. The current expenses of a trout-breeding establish- ment consist of three classes, viz. : i. The rent of the place or the interest on the original outlay, plus the wear and tear, which together should be reckoned at 12%. 2. The care of the fish, which is not much for a small stock of trout, and grows (comparatively) less the more fish you have. 3. The cost of feed, which is very small, amounting, perhaps, to 3 cents a pound. All which items of expense do not make the full- grown trout cost over 15 or 20 cents a pound, if suc- cessfully raised. On the other hand, trout bring from 50 cents a pound to $ 1.25, 75 cents being, I should say, a fair average, at the present time, in the neighborhood of Boston and New York. Here we see a large margin for profit, and I think it is a fair one, when a man raises his trout successfully. It all depends on this, of course. If he cannot keep his trout alive and secure, he cannot expect to make anything at the business. I should say the following estimate approximated the truth : — If you have first-rate water facilities, and should hatch 20,000 young fry and raise them all to be four years old on food at 3 cents a pound, they would cost you, after you began to market the fish, not over 18 cents a pound. If you raise half, all your expenses CONCLUDING CHAPTER. 265 being the same, with the exception of food, they will cost about 24 cents a pound. If you raise one fourth, they will cost somewhere near 36 cents a pound. If you raise one eighth, about 54 cents a pound. If you raise less than this, they will cease to pay a profit. To assist the beginner in estimating his expected ex- penses and returns, I will give the following maxims : — a. Under favorable circumstances, five pounds of meat food may be considered an equivalent for one pound of trout growth with two-year-olds and three- year-olds. b. For any given quantity of two or three year olds one per cent of their weight may be regarded as an adequate average daily ration the year round. c. Two and three year olds will double their weight annually, and can be made to do so in the six months from May to September, by extra care and feeding. d. Good food for grown-up trout, namely, lungs and plucks of slaughtered animals, can be purchased any- where for two or three cents a pound. The cost of the actual food of the young fry the first six months is inappreciable. For further information see chapter on food. e. First-class trout bring $ i.oo a pound in Fulton Market in April, and can be forced, almost any time, when in season, at 50 cents. f. Freshly killed trout, well packed in ice and saw- dust, will stand a direct journey in the summer, by rail, of five hundred miles, without injury. Mr. Stephen H. Ainsworth's estimate of profits, published five years ago (1866), is as follows: — 266 DOMESTICATED TROUT. Cost of buildings and fixtures $ 6,000 5,000 parents for spawn, at 50 cents . . . 2,500 Three men's labor for four years, at $300 per year 3,600 Cost of food for 1,000,000 trout for 4 years . . 20,000 " " " " 3 years . . 10,000 " " " " 2 years . . 4,000 " " " " i year . . 1,000 Total $47,100 Now for their value. The million of four-year-olds will aver- age a pound each, and are worth at least twenty-five cents per pound in the pond, which makes the 1,000,000 4-year-olds worth .... $250,000 " 3-year-olds, £ pound each . . 175,000 " 2-year-olds, £ pound each . . . 87,000 " i -year-olds, 7 oz. each . . . 30,000 The worth of all trouble at the end of four years Deduct the price of growing .... Profit $ 495.000 As these figures stand, they cannot serve as a guide to fish-breeders at present, for no one begins to carry on the business on this immense scale. But suppose we divide the figures by 50, which brings the scale within reach, we then have a profit of $ 10,000 on an establishment turning out 20,000 four-year-old trout annually. This, I believe, would be not far from the truth but for one item, which Mr. Ainsworth did not take in, but which closely follows every business like an evil genius, namely, risk. What this fluctuating item ought to be in the above calculation, I will not attempt to say, but I am afraid that at the time the estimate was made it was more than enough to swal- low up the profits. It has been growing less and less CONCLUDING CHAPTER. 26/ every year, as trout growing has become better under- stood, and I believe the time is near at hand when Mr. Ainsworth's figures may be realized on a reduced scale, with not more than 50% deducted from the profits to cover the items of risk. It may occur to some to inquire what makes the item of risk so large. I will reply that it is because the business is new, and but little understood, the subject-matter is of a peculiarly hazardous sort, and, perhaps more than all, fish-breeders will not take pains to insure the security which is absolutely necessary to success, and which has been dwelt upon so emphati- cally in earlier portions of this treatise. These things have made the risk very great, and account for the very significant fact, that, in the five years since Mr. Ainsworth's table was published, no one has made a fortune by raising trout for the table, or even to my knowledge derived any very extraordinary income from this source alone. I think, however, the next five years will tell a dif- ferent story, and I am very much mistaken if some of the trout ponds now under way do not yield within that time some very handsome returns from their mar- keted trout. Thus far we have considered the business of trout growing in only one of its branches of profit, namely, raising marketable trout. There are, as is well known, two other sources of revenue : — 1. The sale of spawn. 2. The sale of young stock. The first branch can hardly be considered a legiti- 268 DOMESTICATED TROUT. mate branch on which to base permanent returns, be- cause the sale of spawn is limited to establishments that are just commencing operations. This trade is a large one now, because so many establishments are starting ; but these will soon furnish their own spawn and be- come sellers instead of buyers, and when the prospec- tive fish-breeding operations of the country are all under way there will be a great supply of eggs with a very disproportionate demand. Indeed, the prospect is that the spawn trade will not be a permanent one of any great value, and therefore cannot be regarded, in its present state at least, as a legitimate ground for basing permanent expectations. It is not so, however, with the trade in young fry and yearlings for stocking other waters. It is a uni- versal custom now with owners of small gardens to buy their young cabbages and tomatoes, and other vegetables, of the large producers, because it is cheaper than to start them themselves. Farmers also buy their pigs, instead of breeding them, from the same cause. Now it is only reasonable to expect the same rule to prevail in fish raising, as it certainly does at present. Many persons who have ponds and streams, and want to keep them stocked, will prefer, and will find it cheaper, to buy their young stock every year than to work all winter at hatching the eggs. The trade in young stock, therefore, looks as if it would be permanent, and appears to be a legitimate source from which to expect an income in trout-raising. This forms at present a very considerable item in the business. Young fry are in great demand in New CONCLUDING CHAPTER. 269 England* at $25 a thousand, and yearlings at $100 a thousand. Many thousands of them could be sold at this day for these, and even at an advance on these prices, if the fish could be had. The supply this year (1871) has not nearly kept up with the de- mand. We here find in the sale of young stock quite an addition to the sources of the trout grower's income, and I am informed by those who are operating near the large cities that a very considerable revenue could be obtained at their places by charging an admission- fee to visitors. There is also money to be made by buying and fat- tening trout for the market, when you can buy them cheap enough. Good thriving trout less than four years old will double their weight in a year, and some- times much more. Therefore, if you put a thousand pounds of them in a pond, securely protected, they will * The price-list of Cold Spring Trout Ponds for 1871 is as follows : — Trout Spawn, warranted live and healthy, per thousand $ 10.00 Young Trout, one inch long, first thousand . . . 30.00 Each additional thousand 25.00 Yearling Trout, four or five inches long, per thousand 100.00 Trout for the Table, dead weight, per pound . . . i.oo Salmon Spawn, warranted live and healthy, per thousand 50.00 Each additional thousand 25.00 Young Salmon, first thousand 100.00 Each additional thousand 50.00 Young Black Bass, first thousand 50.00 Each additional thousand 25.00 This is a fair statement of prices current. Some dealers charge more, some charge less. 2/O DOMESTICATED TROUT. in a year become two thousand pounds, and the feed in the mean time will not cost over one hundred and fifty dollars. That is to say, the increase will cost you not over fifteen cents a pound. When these various sources of income are taken into account, in connection with the wide margins for profit, it is obvious that successful operations cannot but pay well. I would say, however, in conclusion, that I do not wish to hold out false inducements to persons to go into the business with the hope of mak- ing great fortunes. The item of risk is a very serious one yet, and small operators cannot expect to make more than a fair living. With many it will not pay at all, while it is reserved only for the very successful, and for those who have the few great water facilities of the country, to make the great fortunes. SECTION II. — RECAPITULATION. WATER. Cautions to be observed in selecting Water for Trout Breeding. Beware of, 1. Insufficient water. 2. Freshets. 3. Water that heats in the summer. 4. Water intrinsically unsuitable. PONDS. Points to be secured in building Ponds. 1. Excavate, rather than dam up. 2. Build compactly. CONCLUDING CHAPTER. 2/1 3. Build small ponds for business. 4. Be able to draw off the water. 5. Avoid hiding-places. 6. Protect ponds thoroughly. BUILDINGS. A full set of buildings or rooms consists of, 1. Hatching apartment. 2. Meat apartment. 3. Store-room and carpenter's shop. 4. Office. 5. Ice-house. THE HATCHING APPARATUS. The hatching apparatus consists of, 1. Supply reservoir. 2. Aqueduct. 3. System of filters. 4. Hatching apparatus proper. THE NURSERY. The points to be secured about the nursery are, 1. A fall of water. 2. A current. 3. Protection from suction against the screens. 4. Security from overflow. 5. Absence of fixed hiding-places. 6. Compactness. 7. Protection against natural enemies. 8. Perfectly tight compartments. 2/2 DOMESTICATED TROUT. TAKING THE EGGS. The directions for taking the eggs are, 1. Use eggs that flow easily, and no others. 2. Use ripe milt, and no other. 3. Make quick work. 4. Stir well while stripping. 5. Allow time for eggs to separate. 6. Rinse thoroughly. HATCHING THE EGGS. Dangers. Remedies. Fungus. Carbonized wood. Sediment. Flannel filters. Living enemies. Covers. Byssus. Daily examination. ALEVINS. Dangerous Instincts* 1. To hide. 2. To pursue a current of water. THE YOUNG FRY. Directions. 1 . Have healthy well-fed breeders. 2. Develop strong and healthy embryos in the egg- 3. Provide suitable place for young fry. 4. Take good care of them. CONCLUDING CHAPTER. 2/3 LARGE TROUT. Precautions. Guard against, 1. Freshets. 2. Overstocking. 3. Heated water. 4. Careless handling. 5. Cannibalism. 6. Fouled water. 7. Natural enemies. 8. Poachers. HOW TO GROW VERY LARGE TROUT. Give them, 1. Plenty of water. 2. Plenty of food. 3. (Relatively) warm water. 4. Wide range. 5. Ample space. APPENDIX. APPENDIX I. A NEW DISCOVERY. — CURE FOR FUNGUS. SALT A CURE FOR MICROSCOPIC PARASITES ON TROUT. IN the spring of 1872 I began some microscopic exami- nations of the parasites on large and small trout, which led to the discovery of a cure for what has hitherto been thought to be incurable disorder. It is well known that when trout become injured or un- healthy a fungoid growth appears in blotches over the sur- face of their backs, usually terminating in fatal results in a few days. It has hitherto been supposed, I believe, that the fungus eats into the tissues of the fish, and destroys it. The mi- croscope revealed, however, that it was not the fungus that penetrated into the fish, but a multitude of microscopic worms of the shape and appearance given on page 278. The worms are never found in the upper parts of the fun- gus, but just below at the roots, or where the fungus joins on to the surface of the skin. Here between the roots of the fungus and the body of the fish are found hundreds of these creatures incessantly in motion and apparently eat- ing vigorously. They are about -fa of an inch in length and ^iir of an inch in diameter, and are provided with a mouth at one extremity and at the other with about twenty claw-like appendages for fastening on to the fish on which they feed. They are continually eating into the tissues of the fish, and the twenty tentacles enable them to fasten on so tightly that the fish cannot shake them off. These para- sites appear to live on the flesh of the fish, and the fungus 278 DOMESTICATED TROUT. to live on the digested matter into which they trans- form it Parasites which attack Large Trout, a Tentacles for fastening to the fish ; b Mouth. This discovery led to some experiments in search of a remedy, and it was found that a strong solution of salt de- stroyed the parasites. Experiments were then made of immersing trout in salt water, and it was found to be per- fectly harmless, if not too long continued. A method was thus found of killing the parasites without killing the fish, which fact was confirmed by actually taking a trout cov- ered with fungus and immersing him in a salt bath for a moment or two, and afterwards keeping him by himself for several days. The fungus peeled off, the parasites APPENDIX I. 2/9 were killed, the bare spots healed over, and the trout got well. Others were tried; some died and some lived. a Microscopic parasites which attack trout fry ; b Water insects supposed to be destructive to trout eggs. From all which circumstances we may, I think, draw the following conclusions : That it is the worm, and not the 28O DOMESTICATED TROUT. fungus, which eats into and kills the fish ; and that the fish can be cured, when not too much weakened, by immersion in a strong solution of salt.* A similar series of experiments led to the discovery that salt is also a cure for the parasites on young fish. These parasites are smaller than those which infest the large fish.f They have a circular form with a diameter of about -g*j of an inch. They are extremely thin, and progress by a rotatory movement. They sometimes swarm in immense numbers upon the young fish that are attacked by them. They do not cause a fungoid growth, as the larger ones do in the larger fish, but the young trout affected with them appear outwardly as clean and well as ever. If the para- sites are not removed, however, the trout will lose their strength and drift down toward the screen, on which they will probably be finally caught and die.£ Salt destroys the parasites, and does not injure the young fry. It is, therefore, a remedy for the parasites. Hundreds of ex- periments which I tried of putting the affected young trout in salt water had the same result, which was to kill the parasites and restore the fish. I will also add in this connection that the salt bath seems to improve the young fish in other ways than by killing the parasites, and one lot of young fry in particular, confined in a small box, which I cured in this way, and to which I gave a pint of salt every day, appeared better than * I used a table-spoonful of salt to a pint of water, and kept the fish in it till he went over on his back, and then took him out and put him instantly into cold running water. t I have sometimes found the larger parasites in small num- bers on the small trout, but have never found the circular para- site on large trout. J This furnishes one explanation of what so many trout breeders have remarked, that their young fry seemed to die when they appeared perfectly healthy. APPENDIX I. 28l any other young fish that I had. I have accordingly come to the conclusion that salt is beneficial to the young fish, and that large quantities can be used to advantage in the nurseries of the young fry, not only for the purpose of im- mersion, but to furnish an essential element in which the water has become deficient. All spring water, it is said, contains a modicum of salt. Perhaps this slight trace of salt is essential to the health of the fish. If so, then salt ought to be supplied artificially when trout are kept in a spring stream where the supply of salt is insufficient. APPENDIX II. JOURNEYS OF LIVE FISH AND EGGS. T) ELOW will be found a brief account of some journeys U with live fish, which may serve as a guide to begin- ners. 1. In May, 1868, I sent 15,000 trout fry to New York City and various intermediate points, in care of Mr. Frank H. Osgood. They left the ponds about 6 A. M., and were carried in ten twelve-gallon tin cans about two thirds full of water. The temperature was kept low and even with ice. The last of the lot did not reach their destination till eleven o'clock the next morning. The water was not changed, but was kept well aerated during the journey. Very few died. Mem. : New tin answers very well to transport fish in, but after it has been standing a long time it should be carefully scoured, as it gathers an oxide which seems to be partly soluble in water, and, at all events, is poisonous to the fish. The young salmon for the Dela- ware River were lost this spring from a similar cause. 2. The same season I sent by express two lots, of 500 trout fry each, to Providence, R. I., about 120 miles, with- out an attendant. They all died on the way. A lot of 500 bass fry sent by express to Framingham, Mass., about loo miles, with two changes of cars, met the same fate. Mem. : It is not safe usually to send live fish without an attendant, at least a part of the way. 3. In the fall of 1868 Mr. Osgood took several yearling trout to the New England Agricultural Fair at New Haven, 157 miles, and exhibited them for several days APPENDIX II. 283 in a tank, occasionally changing the water. They bore the journey and exhibition admirably and without loss, receiving a well-deserved diploma. 4. In the fall of the same year we caught live salmon in a stake net on the Mirimichi River, confined them for a while in a pen made in the river, conveyed them from the pen eleven miles, closely packed in a creel, and put them into a pond. At first many of them became covered with fungus and died, but as the water grew colder the trans- portation injured them less and less, and late in the fall they suffered very little from handling. 5. In December, 1868, in very cold weather, nearly 200,000 salmon spawn, the eye-spots then becoming visible, were packed, at the salmon establishment on the Mirimi- chi, in moss in baskets, and the baskets in large boxes, and taken 100 miles on a sled, 100 miles by rail, 250 miles by steamer, and 220 miles more by rail. They arrived at the Cold Spring Trout Ponds in good condition. 6. The same winter salmon spawn and trout spawn packed in moss were sent to Mr. Frank T. Buckland, H. B. M. Commissioner of Fisheries. The trout spawn arrived in England in first-rate condition, and also that portion of the salmon eggs which did not hatch on the way, but it was so late in the season that some of the embryos hatched and perished. 7. In the spring of 1869, 3,000 salmon fry were sent in two twelve-gallon cans to the South Side Sportsmen's Club, Long Island, in care of an attendant. The water was kept cold with ice, and the salmon did well till about 10 P. M., when they were on the New York steamer, and had been sixteen hours on their journey. At this time the water was partly changed, and water from the boat was used. Nearly 2,000 died immediately, the rest reaching their des- tination safely. 8. Another lot of 2,000, to make up this loss, was sent 284 DOMESTICATED TROUT. soon afterwards, in a similar way, but the water was not changed during the journey, though ice was used freely. They all reached their destination safely, after a journey of about thirty hours. Mem. : It is much safer to keep the fish in water that you are acquainted with than to use that with which you are not acquainted. 9. In the spring of 1869 I had three lots of Lake Cham- plain and Missisquoi River fish transported to Charlestown, N. H., consisting of Black Bass (Grystes fasciatus) ; Glass-eyed Pike (Luciopercd] ; Red-fin Mullets (Catosto- mus) ; White-tailed Mullets (Catostomus) ; Lake Cham- plain Shad, Whitefish (Coregonus) ; Suckers (Catosto- mus) : Mascalonge (Esox, gill-covers bare) ; Pickerel (Esox, gill-covers sealed); Hornpouts, Bull-heads (Pi- melodus) ; Yellow Perch (Perca flavescens} ; Sheep's Head, Drumfish (Amblodori). Their journey was a long and severe one. They were first taken in a seine, and confined in a pound a day or two, then transferred to a hundred-gallon wooden tank, and conveyed ten miles in a row-boat to the village of S wanton, Vt., thence to the railroad station by wagon, thence to St. Albans by rail, where they waited several hours for the connecting train. They then travelled 152 miles by rail to Charlestown, where they were received in a wagon and driven to the Ponds. Ice was used plentifully on the way, probably too much, they being warm-water fish, and the water was more or less aerated. The result was very different with different fish. There were about forty fish in the tank each time, all full grown, and averaging two pounds apiece. All the shad (whitefish) died almost immediately, most of the sheep's- heads died early also, and almost all the glass-eyed pike. The mullets, perch, suckers, hornpouts, and pickerel lived. Most of the black bass lived. The survivors are still at the Cold Spring Trout Ponds, and are doing well. Mem. : Ice should be used cautiously with warm-water fish. The APPENDIX II. 285 Lake Champlain shad (whitefish) cannot be transported in the spring. 10. In September, 1869, ten large trout, hatched at Charlestown, and measuring nearly a foot in length, were taken for exhibition at the Mechanics' Fair in Boston. They survived the journey very well, although they were kept two days and one night in a tank of forty gallons of water. They were ultimately placed in a glass tank in the rotunda of Quincy Hall, where an arrangement had been made to run a constant stream of water over them. The temperature of the water varied from 65° to 73°, but was kept down somewhat with ice. The trout lived about ten days when they all died. A second lot was sent for, which survived the remaining two weeks of the exhibition. They received a silver medal and the diploma of the Associa- tion. 11. In May, of 1870, I transported 1,000 yearling trout to North Brookfield, 109 miles, three changes o'f cars, twelve hours' journey. They were taken in a tank and two barrels, with about eighty gallons of water, which was kept very cold, and well aerated. Forty-one died on the journey. 12. On the 2oth of May, the same year, one very hot day, I carried 10,000- trout fry to Bristol, Conn., 138 miles, twelve hours, with three changes of cars. They were car- ried in six twelve-gallon cans, with about fifty gallons of water. Only seven died on the way. 13. In the fall of 1870 I carried 20,000 trout spawn, just taken, in a pail of water, seven miles in a wagon, with- out loss. 14. In the spring of 1871 I sent 10,000 trout fry to Nor- way, Me., 1 20 miles by rail, 100 by boat, and 40 miles more by rail. The journey took twenty-eight and a half hours. They were carried in a tank, in forty to fifty gal- lons of water, and plenty of ice. There was a loss of about 500, many of which had been bruised by the ice. 286 DOMESTICATED TROUT. 15. In the same spring I took 500 yearlings and 12 large trout, very fat, in the same tank, in forty gallons of water, to Webster, Mass., no miles, in thirteen hours, with three changes of cars. All seemed in first-rate con- dition, with the exception of half a dozen yearlings, which appeared to have been bruised. Mem. /In travel- ling by rail with fish, it is better to have one large tank than several smaller ones, provided you do not carry over about fifty gallons of water. More than this makes it too heavy to be handled safely in the hurry of railway travel. 1 6. On the 2oth of November, 1871, 10,000 trout eggs were packed in sphagnum moss in a common wooden box about a foot square, at Charlestown, N. H. They went from Charlestown to Boston, 120 miles by rail, on the same day. They remained in Boston over night, and the next morn- ing were put on board the ocean steamer which sailed that day. They had a long passage of eighteen days to Liver- pool, and a considerable journey by rail afterwards from Liverpool to Keswick. At the end of the journey two thirds were found in good condition, although some hatched on the way and died, and the byssus generated by these, and by some of the eggs that were killed during the first part of the trip, made great havoc in places. APPENDIX III. ODDS AND ENDS. /"CONTAINING tables of spawn in various fishes ; the ^— ' seasons when fish spawn ; the months when fish are in good condition ; of water plants suitable for fish ponds ; the months when it is illegal to catch trout in the various States ; also trout breeding outfit, tricks for managing domesticated fish, tricks for managing the enemies of fish, etc. NUMBER OF SPAWN IN DIFFERENT FISH. Buckland's Table.* Species. Weight of fish. Trout t I lb. Jack 4 Ibs. Perch £ lb. Roach | lb. Smelt 2 oz. Lumpfish 2 Ibs. Brill 4 Ibs. Sole i lb. Herring \ lb. Mackerel i lb. Turbot 8 Ibs. Cod 20 Ibs. Total number of eggs. 1, 008 42,840 20,592 480,480 36,652 116,640 239,775 134,466 19,840 86,120 385,200 4,872,000 * Buckland's Fish Hatching, p. 13. t It will be seen by this table that in point of yearly increase trout appear at a disadvantage ; but when their superior quality is remembered, one is reminded of the reply of the lioness to the fox, in the fable, when reproached for bringing forth but one off- spring at a birth. The lioness answered, " Unum sed leonem." 23d Fable, Vulpes et Lecena, 288 DOMESTICATED TROUT. Atkins's Table.* • Species. Weight offish. Number of eggs. Yellow Perch 3^ oz. 9i943 River Smelt 2 oz. 25,141 Fresh-water Smelt 10 oz. 80,000 Whitefish (Coregonus) 2 Ibs. 25,076 Schoodic Salmon (average) £ Ib. about 600 Sebago Salmon (full count) 2 Ibs. 10 oz. 2,368 Number of Spawn in other Fish not mentioned in the above Tables. Species. Weight of fish. Number of eggs. Herring 5! oz. 265,650 Flounder 1,000,000 Mullet — 13,000,000 Tench 383,250 Bream 137,800 Carp 66 Ibs. 342,140 Sturgeon 200 Ibs. 7,000,000 Pike 272,160 The following table gives the number of salmon eggs taken at the writer's establishment at Mirimichi in 1868. The fish averaged in weight about nine pounds, and were found to yield, like salmon everywhere else, a very uniform average of 1,000 eggs to the pound, when all the eggs were saved. October 15, 1868, 80,000 eggs from 8 salmon. • 16, « 55,000 « a 5 «( < 17, « 81,500 « n 12 fC i 20, M 8,000 « t€ 2 <« partly spawned. i 21, « 53.000 « t< 8 «« i 23, H 5,000 K « I «( ' 24, « 18,000 M H 3 (( * Maine Fisheries, Report, 1869, p. 24. APPENDIX III. 289 October 26, 1868, 21,000 eggs from 4 salmon.* " 29, " 10,600 " " 2 " The following table is a portion of Seth Green's report to the New York Commissioner of Fisheries of the shad spawning on the Hudson in 1870, showing the number of spawn in shad. Extracts from Report of Shad Fisheries in the Hudson in the State of New York, iS/o.f May 26, caught 20 shad at night, 2 ripe fish, 70,000 spawn. " 27, caught 12 shad, I ripe fish, took 40,000 spawn. " 30, fished at night, got 23 shad, 9 ripe fish, 260,000 spawn. " 31, caught 74 shad, 8 ripe fish, took 210,000 spawn. June i, caught 35 shad, 4 ripe fish, took 100,000 spawn. " 2, caught 108 shad, 6 ripe fish, took 150,000 spawn. " 3, caught 90 shad, 12 ripe fish, took 250,000 spawn. " 4, caught 133 shad, 7 ripe fish, took 165,000 spawn. " II, caught 86 shad, 7 ripe fish, took 165,000 spawn. " 12, caught 70 shad, 1 1 ripe fish, took 240,000 spawn. " 13, caught 39 shad, 6 ripe fish, took 120.000 spawn. " 14, caught 32 shad, 2 ripe fish, took 55,000 spawn. The following is the record of the trout spawning during the month of October, 1870, of one pond at the Cold Spring Trout Ponds. The trout averaged about half a pound in weight. Number of eggs. Number of fish. October 12 1,000 2 "15 600 i 1 8 2,400 3 " 19 2,400 4 * It should be observed that the salmon in the river finished spawning by the 24th of October, and that the eggs taken after that time were from the fish captured in the artificial ponds. t New York Citizen, October 15, 1870. 2QO DOMESTICATED TROUT. Number of eggs. Number of fish. October 20 2,500 3 21 2,500 4 " 22 1,800 3 23 1,800 3 " 24 1,200 3 25 2,300 4 26 4,150 8 " 27 4,600 10 28 5,400 ii " 29 2,200 4 " 30 4,200 10 « 31 7,400 13 The following table shows the time of spawning in the latitude of Northern New England of some of our more common American migratory and fresh-water fishes. Migratory Fishes. Smelt ( Osmerus viridescens) April. Shad (Alosa prestabilis) May and June. Alewife (Alosa tyrannus) May and June. Menhaden (Alosa Menhaden) May and June. Striped Bass (Rocctts linealus, Gill, Labrax lineatus, Cuv.) July- Salmon (Salmo salar) October. Fresh-water Fishes. Perch Pike (Lucioperca) Last of April. Pickerel (Esox reticulatus) Last of April and first of May. Yellow Perch (Perca flaviscens) April and May. White Perch (Merone americana) June. Roach (Pomotis appendix) May. Sunfish (Pomotis vulgaris, Cuv.) May. Sucker (Catostomus) May. Rock Bass (Centrarchus