AMATEUR FISHCULTURE

BY CHARLES EDWARD WALKER

AUTHOR OF "OLD FLIES IN NEWDRESSES" "SHOOTING ON ASMALL INCOME, " ETC

WESTMINSTERARCHIBALD CONSTABLE & CO LTD2 WHITEHALL GARDENS

1901

Butler & Tanner, The Selwood Printing Works, Frome, and London. 

PREFACE

My aim, in this little book, has been to give information and hintswhich will prove useful to the amateur. Some of the plans and apparatussuggested would not be suitable for fish culture on a large scale, butmy object has been to confine myself entirely to operations on a smallscale. I have to thank the Editor of _Land and Water_ for permission topublish in book form what first appeared as a series of articles. 

CHARLES WALKER. 

Mayfield, Sussex. _March, 1901. _

CONTENTS

 CHAPTER PAGE

 I Introductory 1

 II Stocking Waters with Food 7

 III Suitable Fish and Suitable Waters 14

 IV Trout. Preliminary Hints and Advice 20

 V Trout. Rearing Ponds, Boxes, and Hatching Trays 27

 VI Trout. Management of the Ova and Alevins 34

 VII Trout. Management of the Fry 42

 VIII Trout. The Management of the Fry (_Continued_) 51

 IX Trout. The Friends and Enemies of the Fish Culturist 58

 X Trout. Management, Feeding, and Turning out of Yearlings 67

 XI The Rearing of the Rainbow Trout, American Brook Trout, and Char 72

 XII Salmon and Sea-Trout 81

 XIII Coarse Fish 88

 Appendix 93

 Index 97

CHAPTER I

INTRODUCTORY

Fish culture of a certain kind dates from very early times, but itsscientific development has only come about quite recently. Most peopleknow that in our own country the monks had stew ponds, where they keptfish, principally carp, and also that the Romans kept fish in ponds. Inthe latter case we hear more often of the eel than of other fish. Thebreeding of trout and salmon, and the artificial spawning and hatchingof ova, are, however, an innovation of our own time. 

Much has been discovered about the procreation of fish, and in no casehave scientists worked so hard and discovered more than in the case of_Salmonidæ_. Fish culture, particularly trout culture, has become atrade, and a paying one. To any one who has the least idea of thedifficulties to be overcome in rearing _Salmonidæ_, this fact aloneproves that fish culture must have progressed to a very advanced stageas a science. 

This advance has in very many, if not in the majority of cases, beenmade by the bitter experience gained through failures and mishaps, forthese have led fish culturists to try many different means to preventmischances, or to rectify them if they have happened. Some of the mostserious difficulties experienced by the early fish culturists who bred_Salmonidæ_ can now be almost disregarded, for they hardly exist for themodern fish culturist, with the knowledge he possesses of the experienceof others. 

So much of what has been done in fish culture is generally known tothose who have studied and practised it, that the beginner can nowadayscommence far ahead of the point whence the first fish culturistsstarted. Many of his difficulties have been overcome for him already, and though he will not, of course, meet with the success of the man ofexperience, still he ought with the exercise of an average amount ofintelligence to avoid such failures as would completely disgust him. 

There are many pieces of water containing nothing but coarse fish whichare very suitable for trout of some kind. Ponds, particularly thosewhich have a stream running through them, will, as a rule, support agood head of trout if properly managed. Again a water which containstrout may become more or less depleted, and here it is necessary tosupply the deficiency of trout by some means. The easiest way is, ofcourse, to buy yearling or two-year-old fish from a pisciculturalestablishment, of which there are many in the kingdom, but I know thatthere are many fishermen who would much prefer to rear their own fishfrom the ova, than to buy ready-made fish. Any one who has the time andopportunity to rear his own fish will be amply repaid by the amusementand interest gained, and it should be the cheaper method of stocking orre-stocking a water. 

The same remarks apply to a certain extent to waters which will notsupport trout, or where the owner wants more coarse fish. The stock ofcoarse fish may be improved by fish culture just as much as a stock oftrout. 

In his first year or two, it is very possible that the amateur will notsave very much by being his own pisciculturist. If, however, he iscareful, and works with intelligence, it is quite possible that he maysucceed better than he had hoped and rear a good head of fish at a lesscost than the purchase of yearlings. In any case he will have had agreat deal of pleasure and gained experience as well as reared somefish. 

In the present little volume, I propose to try and deal with fishculture in such a way as to help the amateur who wishes to rear fish tostock his own water. Much of the existing literature of the subjectdeals with it on such a large scale that the amateur is frightened toattempt what is apparently so huge an undertaking. Fish culture may, however, be carried out on a small scale with success, and thoughconsiderable attention is necessary, particularly with young_Salmonidæ_, it is not a task which involves a very great proportion ofthe time of any one undertaking it. It is absolutely necessary, however, that the amateur fish culturist should live on the spot, or have someone who is intelligent and perfectly trustworthy who does. In every casein my experience, trusting the care of young fish to a keeper or servanthas resulted in failure, and in every failure I have seen where the fishhave not been trusted to the care of a servant, the cause has been veryobvious, and could easily have been avoided. 

The rearing of trout is the most important branch of fish culture to theamateur, and fortunately but slight modifications are necessary inrearing other fish. What is good enough for trout is good enough formost fish, therefore I think that I shall be right in describing troutculture at considerable length, and dealing with other fish in asomewhat summary manner. The difference in the management, etc. , ofother fish I shall point out after describing how to rear trout. 

To begin with, the amateur must not suppose that because he puts fishinto a stream or pond he will succeed in stocking that water orincreasing the head of fish. There are many other things to beconsidered. The river, stream, or pond must be of a suitable characterfor the fish, and there must be plenty of food. I am sure that it ismuch more important to consider carefully whether the water is suitable, and contains a proper supply of food, than to consider how the fish areto be obtained, for recourse may always be had to a professional fishculturist--fish of almost any kind and any age can be bought readymade. 

The point I would impress upon the amateur more forcibly than anythingelse, is that he should be sure that there is plenty for his fish to eatin the water, before he thinks of putting them into it. It is for thisreason that I devote my next chapter chiefly to the stocking of waterswith food and to the improvement of the food supply in waters where somefood already exists. 

CHAPTER II

STOCKING WATERS WITH FOOD

It may seem somewhat superfluous to say that fish cannot live in anywater unless that water contains the food supply necessary for them tothrive upon, and yet this is the point most often overlooked in stockingwaters with fish. Small attempts at stocking with creatures suitable forfood, particularly after the fish have been already introduced, are notat all likely to succeed. Such an important matter when treated as asmall afterthought is almost sure to end in failure of the wholebusiness of stocking. 

But a small amount of thought will convince any one that in order thatthere may be a sufficient amount of animal life in a water, there mustbe an adequate vegetable life, for weeds are almost always necessary tothe well-being of the creatures which serve as food for fishes. 

In the case of a pond it is generally fairly easy to introduce a goodstock of suitable weeds. The best method is to let the pond down as lowas possible, and then to plant some weeds round the margin; the water isthen allowed to gradually fill up the pond, and as it rises weeds areplanted round the rising margin of the water. In ponds which cannot beemptied at all, or not sufficiently to carry out this plan, weeds may beplanted in an easy but not quite so effectual a manner. They may beplanted in shallow baskets containing some mud from the bottom of thepond, and then lowered in suitable places from a boat, or bundles of theweed may be tied to stones and dropped into the water in a similarmanner. 

These latter methods are, of course, not so good as actually plantingthe weeds round the advancing margin of the water, for success dependsto a certain extent upon chance. Some of the weeds thus planted are, however, sure to take root and grow. Plants of different kinds, ofcourse, are necessary at different depths and on different kinds ofbottoms, and good kinds are necessary at the margin of the water aswell. I give a list of some suitable plants of each kind at the end ofthis chapter. 

Similar methods are used in planting weeds in rivers and streams tothose used in ponds. If the weeds are planted in baskets, the basketsmust, of course, be weighted when put in a position where the currentcan act upon them. 

Besides vegetation in the water, vegetation on the bank is ofconsiderable importance. I shall deal with this at a later period morefully, as trees and bushes, besides harbouring many insects which serveas food for fish, have also considerable importance in giving cover tothe fish and to the fisherman who is pursuing them. 

I think that in the case of a bare water, a year at least should bedevoted to developing a good supply of vegetation. This will generallyproduce a considerable amount of animal life, without any artificialhelp, but judicious help will be sure to accelerate matters to aconsiderable extent. I would, however, advise the amateur not to attemptto introduce a quantity of creatures into his water, until the vegetablelife therein is well established. For instance, though fresh-watersnails are desirable in every trout water, if introduced in largenumbers into a water in which the vegetation is small and not wellestablished, they will eat down the weeds too much and then die off fromdisease caused by want of sufficient nourishment. 

Having established the vegetable life well in a water, and developed itto a considerable extent, the amateur may begin to examine his water, and find out how much animal life exists there, and to stock withcreatures suitable for food, according to what he finds in the water. 

Fresh-water snails are always desirable. In streams, or in ponds withstreams running into them, the fresh-water shrimps (_Gammarus pulex_)should always be tried. It does not do in some waters, but where it doesthrive it increases very rapidly, and forms about the best article offood that can be given to trout. _Corixæ_, which thrive in ponds andsluggish waters, should always be introduced. They increase rapidly, andare taken by most fish, particularly by trout. The amateur should becareful when he introduces these creatures to make sure that he isputting in the right creature. The water-boatman (_Nautonecta glauca_)is a member of the same family, but is no use as food for the fish. Heswims on his back, is longer and narrower than are _Corixæ_, which donot swim on their backs, are smaller, broader, and live much more underwater than the water-boatman. It is generally advisable to avoidwater-beetles, as most of them are more likely to do harm than good, such a number of our water-beetles being carnivorous. They will probablynot harm adult fish, but they will destroy ova and fry. I have known a_Dytiscus marginalis_ kill a trout of nearly a quarter of a pound inweight. 

In order to make sure of not introducing carnivorous water-beetles intoa water, I think it best as a rule not to introduce beetles at all. _Corixæ_ are, however, so like beetles, that many people call thembeetles, and therefore I will give a few points which will make themeasily distinguishable from each other. In beetles, the wing-cases(elytra) meet exactly in the middle line, in _Corixæ_ and otherwater-bugs, the anterior wings, which resemble the elytra of beetles, overlap, which causes the line on the back to curve away to one side atthe lower end. In beetles the wings which lie under the wing-cases arefolded up on themselves, and when spread out are much larger than thewing-cases. The wings are transparent and very delicate. In _Corixæ_ theposterior wings, which lie under the hard and horny anterior wings, area little shorter than the anterior wings; they are not folded up onthemselves and are not so delicate and transparent as the wings of thebeetle. 

Such small creatures as _Daphnia pulex_, _Cyclops quadricornis_ and_Rotifera_ should be introduced into ponds. 

Snails (_Gasteropoda_) may be roughly divided into three classes, according to the shape of their shells: (1) Flat-shaped coils (type_Planorbis corneus_); (2) Oblong-shaped, somewhat like a trumpet (type_Limnæa stagnalis_); and (3) Ear-shaped (type _Limnæa auricularia_). _Limnæa auricularia_ is particularly suitable for deep waters, and _L. Pereger_, whose shell is of type 2, is a most valuable addition to thefood supply in any fish pond. It is one of the commonest of ourfresh-water snails. 

Mussels (_Conchifera_) are another valuable article of food. There are agreat many different kinds, and the larger ones should, as a rule, beavoided. _Sphæriidæ_ and _Pisidia_ are probably the best. 

In many cases it is advisable to attempt the introduction of some flieswhich are not present. There are several cases in which the May-fly hasbeen successfully introduced, and also the Grannom. Small _Ephemeridæ_seem to me preferable to any other flies. 

With regard to suitable plants for comparatively deep water in ponds orlakes, lakewort and stonewort grow on the bottom, and do not, as a rule, attain any considerable height. White and yellow water-lilies also growin fairly deep water; the water-lobelia is also an excellent plant forponds. 

In streams some of the best plants are water-crowfoot, water-starwort, and the great water moss. Anacharis should not be introduced into anywater, either pond or stream, unless it can be kept down easily. It willotherwise become an unmitigated nuisance. 

Marginal plants are a very important consideration, and plenty of themshould be grown. Water-celery and water-cress are perhaps the bestfood-producing marginal plants that can be grown. Bullrushes andbrooklime are also good, but the bullrushes must be plantedjudiciously. 

CHAPTER III

SUITABLE FISH AND SUITABLE WATERS

Having stocked his water with suitable vegetation and food, the nextmatter which should engage the attention of the amateur, is what fish hehad better introduce. He should, where there is a fair chance ofsuccess, introduce a trout of some sort, as they give better sport thancoarse fish. 

The introduction of salmon into a river is not likely to be attempted bythe amateur, but the head of salmon frequenting a river is undoubtedlyaffected in the most marvellous manner by artificial means. In Canadaand the United States this is particularly remarkable, but theoperations are conducted on a gigantic scale. 

In the case of a stream or river where brown trout already exist, orhave recently existed, in fair numbers, re-stock with these fish, forthey can hardly be bettered in our waters. There are, however, somesluggish rivers where brown trout do not thrive when they areintroduced. In such rivers and in many ponds in the South of England Ibelieve that no better fish exists than the rainbow trout. I sayparticularly in the south, because I do not think that the rainbow troutwill ever really thrive and breed in cold waters. I have at other timesgiven numerous examples which go to show that the rainbow will onlythrive in warm waters. [1] I will therefore only quote the case of NewZealand. The rainbow trout was introduced into both islands, but whileit thrived amazingly in the warm waters of the North Island, it hasproved a comparative failure in the cold waters of the South Island. 

[1] _The Rainbow Trout. _ Lawrence & Bullen, London. 

While the common or brown trout (_Salmo fario_) and the rainbow trout(_Salmo irideus_) are, in my opinion, to be strongly encouraged in thewaters suitable to their respective qualities, the American brook trout(_Salvelinus fontinalis_) does not seem to have met with the approval ofmost of the authorities on pisciculture in this country. My experienceof this fish is not sufficient for my holding any very strong views withregard to its suitability to British waters. In one case I know that itwas a great success for two seasons, but I have not had any opportunityof following it up in this particular instance. In another case it was adecided failure. I am sure that it should not be introduced into streamswhere brown trout thrive, and I am doubtful of its ever succeeding inwaters which are suitable to the rainbow trout. 

Of all the trout, the rainbow is the hardiest, and the one with whichthe amateur pisciculturist is most likely to be successful. It is alsothe fish most likely to supply a want felt by very many fishermen, agood sporting fish in waters where the common trout will not thrive. 

In large and deep ponds with a good stream, or in lakes, char may betried with a prospect of success. They require cold waters, and I havenever heard of their being successfully introduced in the South ofEngland. They are a more difficult fish to rear than trout. 

Grayling have many violent opponents, but I am inclined to think thatthey do but little if any harm in a trout stream, and they supplyexcellent fishing during part of the close season for trout. They seemto thrive best in chalk streams, but there are no doubt many waterswhich would carry a good head of grayling which at present contain onlytrout. They probably do much less harm than most of the coarse fishconstantly found in trout streams. The great crime attributed to them isthat they eat the spawn of the trout, but I am inclined to think thatthe harm they do in this way is much over estimated. They spawn at adifferent time and would not be likely to frequent the spawning placesat the same time as the trout. I have no doubt that an infinitelygreater proportion of trout ova are eaten by the trout themselves thanby grayling in rivers which contain both fish. Chalk streams and thoserivers with gravelly bottoms and with alternate shallows and pools seemto be the most suited to the grayling. 

Among coarse fish the rudd is one of the best from the fly-fisher'spoint of view. It takes the fly readily, is very prolific and very easyto introduce. It thrives remarkably well in ponds which contain a goodsupply of food. Its fry serve as excellent food for other fish, particularly trout, but I have known cases where it increased rapidly ina pond at the expense of the trout. It can, however, be kept under byjudicious netting. 

The dace is another fish which gives sport to the fly-fisherman. It willnot thrive in ponds. In some rivers, however, where trout--brown trout, at any rate--will not thrive, the dace does very well. In the case ofthe Sussex Ouse this is most remarkable. Little more than ten years agothere were no dace in that river, now it swarms with them. Theirpresence is attributed to the fact that some dace, brought there aslive-baits for pike, escaped destruction and established the presentstock. Sluggish and muddy rivers seem to produce the best dace. Chubb, which also possess many points to recommend them to the fisherman, willalso do well in such rivers. 

To those who enjoy bottom fishing and possess a pond, even a small one, I can recommend no fish more highly than the king-carp. It is a muchbolder-feeding and gamer fish than the common carp, and is just as easyto introduce. While dealing with carp I may mention that the goldfish, when introduced into a suitable pond, grows to a very large size. I havecaught them over a pound in weight. 

The perch is a very prolific fish, and will thrive in ponds with a verysmall stream running into them, and in sluggish rivers. Other coarsefish are as a rule easy to introduce into a water. Though perch fry formexcellent food for trout, perch, and of course pike, should be kept outof a trout water. 

The suitability of a water depends to a great extent (as to its capacityof supporting a healthy stock of fish) upon its having plenty ofsuitable vegetation upon the banks. Therefore if the banks are bare ofvegetation, willows and alders, as being quick growing and easilyestablished trees, should be freely planted upon the banks. Thisfortunately is very easily done, for willow and alder sticks cut and putinto the ground in the spring are pretty sure to do well. It is needlessto say that the moister spots should be chosen for the willows, thoughthey will do well in suitable soil in comparatively dry places. Besidesgiving shade and shelter to the fish, which is always an importantconsideration, a considerable quantity of food is bred upon trees andshrubs at the water side. I have found as many as eighteen caterpillarsin the stomach of a trout which I caught under an overhanging oak tree. 

CHAPTER IV

TROUT. PRELIMINARY HINTS AND ADVICE

The amateur who is beginning trout culture had better by all means buyeyed ova from a fish cultural establishment. There are many of these inthe British Isles, and nowadays eyed ova are packed and sent safely allover the country. The artificial spawning of trout is not an undertakingin which the beginner is likely to achieve great success, and thereforeI should advise him to avoid relying upon it when he commences hisoperations as a fish culturist. 

Collecting the ova of wild trout is also an operation of somedifficulty, and lays the beginner open to much more disappointment thanif he deals with eyed ova purchased from a reliable establishment. Instead of having to watch and care for the ova through a critical anddangerous period, he receives them shortly before the young fish hatchout, when the ova are not in the most delicate stage. 

It is of the greatest importance that everything should be ready for theova long before they are expected, as hurry and new apparatus are likelyto cause failure. Any concrete and varnished or enamelled woodworkshould be exposed to the action of a current of water for at least fiveor six weeks before they are brought into actual use. 

The choice of a suitable spot in which to make his hatchery is a seriouspoint for the consideration of the amateur. A spring is the best watersupply as a rule, for the water is usually of a fairly even temperature, and does not require filtering, but water from a stream where trout areknown to live is quite safe. A few years ago it would have beennecessary for any one wishing to take up fish culture, to erect abuilding in which to place his hatchery if he intended to hatch anynumber of eggs, in order to guard against frosts. At the present time, the eyed ova of even the brown trout (_Salmo fario_) can be obtainedsufficiently late to be safe against a frost severe enough to cause anydamage, and as the rainbow trout (_Salmo irideus_) spawns in Februaryand March, the amateur is, at the time he receives the eyed ova, quitesafe from frost. 

The best method to pursue is to make long narrow ponds, with a currentrunning through them, and to hatch the eggs out in trays and boxessuspended in these ponds. When the young fish hatch out, the trays whichcontained the ova can be removed, and the young fish kept in the boxes. Later on the young fish can be released from the boxes into the ponds. Ishall subsequently describe how these ponds, trays, and boxes should bemade. 

The rearing ponds should be made, if possible, at a fall in the level ofthe water supply, so that they may be easily emptied. This is animportant point which is frequently overlooked by amateurs. There shouldbe an outlet on a level with the bottom of the pond, and if the waterescapes through a pipe, that pipe should incline downwards. This, in aseries of ponds, of course necessitates the ponds being at differentlevels, but the water is thus under much better control than if theoutlet is at a higher level, and the ponds are easily emptied. Pondsmay, however, be worked successfully with the outlet in mid-water, oreven near the surface, though this does not ensure such a certainty ofchange of water throughout the pond. It is not, however, always possibleto obtain such a difference in level between the supply and waste. Insuch cases the ponds should be made shallower near the outlet. 

A popular idea seems to be that a gravel bottom is necessary for thewell-being of trout; this is quite a mistake. Personally, I believe thata good earth bottom is best in a rearing pond, and even in a pond linedwith concrete I should always put a layer of mould, preferably turfmould, at the bottom. With the use of this mould during the subsequentoperations in rearing trout I shall deal later on. 

The size of the ponds, of course, depends upon the number of trout to bereared. It is better to have several medium sized ponds than one largeone, as then accident or disease occurring in a pond will only affect aportion of the stock of fish. Mr. J. J. Armistead in _An Angler'sParadise, and How to Obtain It_, says: "A pond sixty feet long, fourfeet wide, and about three feet deep, will hold ten or fifteen thousandfry at first, and give them plenty of room to grow, but by the end ofJuly the number should be reduced to five thousand, which may be lefttill October, when they should again be thinned out, or, better still, put into larger pond. "

I should advise the amateur who is dealing with only a few thousand fishto work on a smaller scale in these proportions, and to make thesechanges gradually, and yet more gradually as the season advances. Thatis to say, work with a third of the number of fry in ponds half the sizeand move some fish several times before the end of July. As Octoberapproaches, make changes of smaller numbers of fish more frequently. 

Late in the autumn is, in my opinion, the best time to put the youngfish into the water they are to inhabit permanently. It must be amistake to rear them artificially longer than is necessary, and by theend of November they should be fairly capable of looking afterthemselves. 

Trout, which are artificially reared on chopped meat and other softfoods, suffer from a lack of development in the stomach walls, and also, probably, in the rest of their digestive apparatus. The first case I sawof the stomach of an artificially reared trout was a two-year-oldtrout, upon which Dr. C. S. Patterson performed an autopsy. The stomachwalls were as thin as a sheet of tissue paper. At the time I believed, and, if I remember rightly, he also thought that this was due toatrophy, but I am inclined to think that this idea was only partiallycorrect. The stomach walls of the autumn yearling trout, which isartificially reared on soft food, do not show any marked abnormality inthe way of thinness; but as the trout's age increases, so does thethickness of the stomach wall decrease in proportion to its size. Thisleads me to believe that the development of the stomach wall, at anyrate, and probably also of the glands secreting the gastric juice andthe digestive apparatus generally, gradually ceases when at about theage of eight or nine months if the trout is fed upon soft food. Probably, also, a certain amount of atrophy and dilatation of thestomach wall is produced. If my observations are correct, so also is theconclusion that a trout which cannot digest hard food, of which a greatpart of his natural food consists, will not have a really fair chancewhen turned out. Therefore, I say, turn out your trout in November, unless you can feed them on such food as shrimps, snails, bivalves and_Corixæ_; and if you stock with "ready made" fish, stock with yearlingsin the late autumn. 

The turning out of his fish in November will also allow the amateurplenty of time to prepare his ponds and apparatus for next year'soperations. If the ponds are made on a stream, probably the very bestplace that can be chosen is where there is a fairly sharp bend in thestream just below a fall. An artificial fall can often be made where thebanks are high by damming up the stream several feet. Care must betaken, however, to avoid any risk of the ponds being flooded. 

CHAPTER V

TROUT. REARING PONDS, BOXES, AND HATCHING TRAYS

Having decided upon a suitable spot, the amateur must now proceed tomake his ponds. Whether he derive his water supply from a spring or froma stream, the amateur had better bring it into his ponds through a pipe. A three-inch pipe will be large enough for a pond thirty feet long, three feet wide, and two feet deep at the deepest part. It is a goodthing for the water to fall, some inches at any rate, through the airbefore it reaches the pond, and in a series of ponds with only onesupply, the water should flow through an open trough with stones andother impediments in it, between the ponds. The ponds may be linedentirely with brickwork faced with cement, and in this case the sidesshould be made perpendicular. The cement should, however, be exposedfreely to the action of the running water for a couple of months atleast before any ova or fry are introduced. 

Another plan, and a simpler and less expensive one, is to face only theends of the ponds with brick and cement work, carrying the brickworkinto the earth on each side, as shown in Fig. 1. In this case the sidesof the ponds should be slightly sloped as shown in Figs. 2 and 3. It isadvisable if possible to make the outlet at the level of the bottom ofthe pond, if the pond is lined with cement, but if the pond is onlycemented at the ends, it is better to have one in mid-water or even nearthe surface. As I have said before however, an outlet should be made atthe level lowest part of the bottom, so as to facilitate the emptying ofthe pond. The pond should however be made shallower at the lower end. Fig. 2 shows a section of the upper end, and Fig. 3 of the lower end ofsuch a pond. 

[Illustration: Fig. 1. ]

[Illustration: Fig. 2. ]

[Illustration: Fig. 3. ]

The open trough between ponds in a series should be at least three yardsin length, but it is better if not straight. Stones and gravel should beput in these troughs in order to make the water as rough as possible, and if some fresh-water shrimps can be introduced so much the better. 

If the water is taken from a stream, a leaf screen must be placed atsome distance in front of the inlet. This may be made of a hurdlefastened to strong stakes sunk into the bed of the stream. The openingof the inlet should be at least double the size of the sectional area ofthe pipe through which the water is carried to the ponds, and should besome distance, a couple of feet if possible, below the surface of thewater. It is a good thing to put a wire cage over the inlet, and underthis a perforated zinc screen is necessary. The inlet from the streamshould be so placed that it is easy to get at and clean. The best formof covering for the inlet into the pond I have seen, is a zinc cylinder, the base of which fits over the end of the inlet pipe. The part of thiscylinder, which projects 18 inches beyond the pipe, is perforated, as isalso the flat end. This can easily be taken off and cleaned, and breaksup the water, making it fall into the pond like a shower bath, causingconsiderable aeration. 

The inlet from the stream should have a trap with which the water may beshut off, as also should the outlet from the pond. When the cylinder onthe inlet into the pond is taken off for a minute or so to be cleanedout, both these traps must be closed. This lessens the chance of anycreatures likely to do harm getting in during the cleaning. Theperforated zinc screen at the inlet from the stream will probably stopany such creatures, but too great care cannot be exercised, and it isalways best to be on the safe side. 

Movable covers of netting over the ponds are most certainly advisable, particularly if the rearing ponds are in an unfrequented spot near astream. On one occasion I caught four kingfishers during a period ofthree weeks, all of which had in some way got under some herring net, which was pegged out carefully over a rearing pond containing trout fry. I never found out how they got in, but once in they were unable toescape. 

Ponds such as I have described are of course for the fry when they havereached a certain size, and have already begun to feed well. Otherappliances are necessary for hatching out the ova and for the young fishwhen first hatched. A very good apparatus may be made from a champagnecase. This should have large square holes sawn through each end, leavingenough wood to ensure strength and solidity to the box. The box shouldthen have two coats of asphalt varnish, and the square apertures coveredwith fine perforated zinc. A still better box may be made at a smallcost. This consists of a box with a wooden bottom and perforated zincsides which are supported by a stout wooden frame. 

Beyond these boxes all that are required are some perforated zinchatching trays. These should be 1-1/2 inches deep. They are very easilymade, and the ova hatch out well in them. Though ova sometimes hatch outvery successfully even when piled up in two or three layers, it is saferto have them in a single layer. The trays should be suspended in theboxes, and the boxes in the ponds close to the inlets, so that a goodcurrent of water may flow through them. The bottom of the boxes shouldbe covered with a thick layer of gravel, but the trays are to be usedwithout gravel. It is advisable to have as much grass as possible roundthe ponds, and such trees as willows and alders should also be plantedround them. Willows and alder sticks planted in the early part of theyear come into leaf in the same spring, and afford shade to the youngfish in the summer. Some suitable weeds should also be grown in therearing ponds. Water-cress, water-celery, water-lobelia, starwort, andwater-milfoil, are all good. They should be arranged, however, so as toprevent as much as possible the little fish finding hiding places, andit is for this reason also that I have recommended slightly slopingbanks when the sides of the ponds are not made of cement. The weedsshould be planted some time before the little fish are turned out ofthe boxes. 

Finally, I must caution my readers again on one or two points before Ileave the subject of the hatching trays, rearing boxes, and ponds. Enamel, varnish, or charr all woodwork thoroughly, leaving no speck ofwood bare and no crack open. Let the water run through and over all yourponds and apparatus for as long as possible before you beginoperations. 

CHAPTER VI

TROUT. MANAGEMENT OF THE OVA AND ALEVINS

Everything should now be ready for the reception of the ova. The rearingboxes are resting upon stones placed at the bottom of the ponds, withthe edges some six inches above the level of the water, and moored tothe sides to prevent their being moved by the current. The hatchingtrays are suspended in the rearing boxes, or placed upon movable restsin the boxes, with their edges just above the level of the water. 

Notice is usually sent a day or two before the ova are despatched fromfish cultural establishments, so the amateur has no excuse for not beingabsolutely ready for their reception. They are packed in various ways, and nowadays suffer but little in the transit. The ova should always becarefully washed before they are placed in the hatching trays. Mr. Armistead, in _A Handy Guide to Fish Culture_, says:--"If just turnedout of a packing case there may be small pieces of moss or othermaterial amongst them. In any case a wash will do them no harm, and theprocess is a very simple one. Take a pail, half-filled with ova, andthen fill up with water, and with a small lading-can lift some of thewater out, and pour it back again, so as to cause a downward current, which will agitate the ova. Their specific gravity being greater thanthat of water, they immediately retire again to the bottom of the pail, and by at once pouring off as much water as is practicable, any floatingparticles of moss, etc. , may be carried off. Should any be left, theprocess should be repeated, and it may even be necessary to repeat itseveral times. When all is right take a ladle, or small vessel of somekind, say a good-sized tea-cup, and gently ladle out the eggs, and placethem roughly on the grills, where they may be roughly spread by means ofa feather. "

To these instructions I would add some for the amateur, who willprobably deal with a comparatively small number of ova. The ova shouldbe washed in some large vessel full of water in the manner abovedescribed. When the water is quite clear, and the ova clean, they may becaught in mid-water as they are sinking either in the hatching trays orin a cup. If caught in a cup they should be transferred with great careto the hatching trays, and spread out in a single and somewhat sparelayer. They must on no account be poured into the trays from a height. While under water well-eyed ova will stand a good deal of gentletumbling about, but if dropped into the water from even a little heightthe concussion is likely to kill them. 

Mr. Armistead recommends glass grills rather than trays such as I havedescribed, but I have found the trays work very well, and they are verysimple and clean. Glass grills are, however, very excellent, though theynecessitate a somewhat greater initial outlay than do the perforatedzinc trays. 

A German fish culturist has recently recommended keeping a stock offresh-water shrimps (_Gammarus pulex_) in the hatching trays and rearingboxes. He says that the shrimps eat only the dead ova, and never touchthe living ones. They also eat any vegetable or animal _débris_. I havenever tried the experiment myself, and so cannot speak from experience. 

Dead ova should be always removed at once, and the hatching trays shouldbe gone over carefully once or twice a day to see if any are present inthem. Dead ova are easily recognized from the fact that they becomeopaque and white. They are best removed with a glass tube. The thumb isplaced over one end of the tube, and the other end brought directly overthe dead ovum. When the thumb is removed from the end of the tube heldin the hand the water will rush up into the tube, carrying with it thedead ovum. The thumb is then replaced over the end of the tube, which islifted from the water with the ovum retained in it. This tube may alsobe used for removing any extraneous bodies which may get into the traysor boxes. 

A form of fungus known as _Byssus_ grows upon dead ova, and it isprincipally for this reason that they must be removed. Livingstone Stonesays of _Byssus_:--"With trout eggs in water at 40° or 50° Fahrenheit, it generally appears within forty-eight hours after the egg turns white, and often sooner, and the warmer the water the quicker it comes. It isnever quite safe to leave the dead eggs over twenty-four hours in thehatching boxes. The peculiarity of _Byssus_ is that it stretches out itslong, slender arms, which grow rapidly over everything within its reach. This makes it peculiarly mischievous, for it will sometimes clasp adozen or even twenty eggs in its Briarean grasp before it is discovered, and any egg that it has seized has received its death warrant. " Mr. Armistead has known it appear within twenty-four hours. _Byssus_develops only on dead ova. 

_Saprolegnia_, known to fish culturists as "fungus, " attacks both livingor dead ova. If the woodwork is properly varnished or charred, and theova managed thoroughly, there should, however, be but little risk offungus. Light is favourable to the growth of fungus, and, therefore, wooden lids should be placed over the rearing boxes. These should bekept partially on after the young fish have hatched out, and be replacedby covers of fine wire netting spread on closely-fitting frames, whenthe fry have begun to feed. These obviate the necessity of covering upthe ponds during the first stages. 

Many small creatures such as caddis-worms will eat the ova, andtherefore a careful watch should be kept upon the hatching trays as itis marvellous how such creatures find their way in, in spite of allprecautions. Birds of several kinds are also likely to cause greatdamage unless the ova and young fish are carefully guarded from theirdepredations. 

In a short time, probably within a few days of receiving the ova, theamateur will find that the young fish are beginning to hatch out. Theygenerally come out tail first, and in wriggling this about in theirattempts to get further out, they propel the ovum about the bottom ofthe tray. When the little fish attempts to come out head first, hesometimes gets into difficulties and if this is observed, he may behelped by a gentle touch with a feather or a camel's hair brush. 

When first hatched out the young fish have a large translucentprotuberance on the under-surface. This is the umbilical or yolk-sac, and contains the nourishment upon which the little fish lives during thefirst stage of its life after it is hatched. This sac is graduallyabsorbed but until it is absorbed the young fish are called "alevins. "At first the little fish do not require any food, but they generallybegin to feed in about six weeks, and before the yolk-sac is completelyabsorbed. The rearing boxes should be kept partly covered, and thealevins will crowd into a pack in the darker parts at the bottom of thehatching tray. 

The shells of the ova must be removed from the hatching trays. As theyare lighter than the alevins, the current will generally carry them tothe lower end of the tray, whence they may be removed with a piece ofgauze spread on a wire ring, or by raising and lowering the tray gentlyin the water in alternately slanting directions. 

The alevin stage is the stage in which the least mortality should beexpected, and the little fish give but little trouble. There are, however, several diseases besides fungus (of which I have spoken alreadywhen dealing with the ova) from which the alevins may suffer. 

I was, I believe, the first to describe (in the "Rainbow Trout") apeculiar disease from which alevins suffered. When hatched out and keptin water containing a very large quantity of air in solution, I foundthat sometimes alevins developed an air bubble in the yolk-sac. Ondeveloping this bubble they are unable to stay at the bottom as theyusually do, but swim about on their backs at the surface, with part ofthe yolk-sac out of the water. An effectual cure for this is to put theaffected alevins into still water for about thirty-six hours. I haveobserved this affection in the alevins of the rainbow trout (_Salmoirideus_), the common trout (_S. Fario_) and the Quinnat or CalifornianSalmon (_Onchorynchus conicha_). 

"Blue Swelling" of the yolk-sac is another disease from which alevinssometimes suffer, but I have never heard of any cure for this. Another, "paralysis, " may be caused by lack of sufficient current and byinsufficient aeration of the water. Sickly alevins will, as a rule, dropout of the pack, and lie on the bottom or against the end of thehatching tray, where they are carried by the current. 

Dead alevins should be removed at once, and for this reason it isnecessary that the hatching trays should be examined at least once aday. 

CHAPTER VII

TROUT. MANAGEMENT OF THE FRY

A greatly varying period of time having elapsed and the yolk-sacs of thealevins being nearly absorbed, the fish culturist will see that some ofthe little fish begin to leave the pack at the bottom of the tray, andto swim up against the current. When this is observed some very finelydivided food should be offered to these alevins. They will probably dartat the minute pieces of food floating past and a little more may then begiven to them. If, however, they do not take any notice of little piecesof food or any other matter which floats past them, they should not betried again till the next day. In a few days from the first of thealevins beginning to feed, all of them will be working up with theirheads to the current, darting at any particles floating in the water. The tray should now be lowered so that its edge is some three or fourinches below the surface and the little fish allowed to swim out intothe box. 

As soon as the yolk-sacs of the alevins are absorbed the little fishcease to be alevins, and are called "fry. "

The alevin stage was that in which the fish give least trouble, thestage I am now describing is that in which they give most. They must befed frequently--at least four times a day. "Little and often" is themaxim which should rule the actions of the fish culturist with regard tofeeding the fry. If he can only feed his fish four times a day, he mustspend some time on each of these four occasions. The food must not bethrown in all at once. If this be done the little fish will not get halfof it; the other half will sink to the bottom. 

The food should be introduced in small quantities at a time, and if theamateur has several boxes he should put a little food into each insuccession, coming back to the first when he has put some into the last, repeating this operation at least half a dozen times. The less he putsin at each time, and the oftener he does it, the better. The ideal planwould be to put a very small quantity of food in each time, and to go ondoing this at intervals of from five to ten minutes all day. 

Livingstone Stone says, "You need not be afraid of the young fry'seating too much. " And again, "I never knew any healthy young fry of minedecline eating but once, and then I had fed them incessantly for twohours, at the end of which time they gave up, beaten. " Personally, Ihave found no limit to the time that the fry will continue feeding. Ihave kept on putting small quantities of food into a rearing box for awhole afternoon, and I was tired of feeding before the fry were tired ofeating. My reader will infer from this that I believe that the frycannot be over-fed, and this is to a certain extent true. If finelydivided food is given in such small quantities that practically none ofit sinks to the bottom without their having a fair chance at it, Ibelieve that in a box containing only a couple of thousand fry, it wouldbe found that they never stopped feeding during the whole day. If, however, too large pieces of food are offered to the little fish, manyof them are likely to be choked and to die, from trying to swallow apiece a little too big for them. 

The amateur will observe that shortly after the fry have been let outinto the box and are feeding freely, they will separate into two more orless distinct groups. One at the upper end where the current comes inand is strongest, and one at the lower end. The fish at the upper endare the strongest and largest. This difference becomes more marked astime goes on, and in six or eight weeks after they have begun to feedthe larger fish will be almost double the size of the smaller. In themiddle of April, if many fry are in each box, they should be thinnedout, and other boxes brought into use. The smaller fish may then betaken from one or two boxes and put into another by themselves. Infeeding care should be taken that the small and weakly fish get a fairshare of the food. 

No matter how carefully the feeding is managed, some of the food is sureto escape the young fish and sink to the bottom. This, if left as it is, will decay and cause great mischief. A very simple and easily appliedremedy for this evil exists in the use of mould dissolved in the water. Livingstone Stone recommends the mould under a sod, and I have alwaysused this with the most beneficial effect. Earth, besides covering upand deodorizing the decomposing food at the bottom, also contains somematerials which are apparently necessary to the well-being of trout. Toquote again from Livingstone Stone, who was the discoverer of this useof mould: "Earth or mud is the last thing one would suppose suitable fora fish so associated in our minds with pure, clean water; yet it is anindispensable constituent in the diet of young trout, and unless theyget it, either naturally or artificially, they will not thrive. "

The effect of earth given in this way upon the young fish is simplymarvellous. They become more lively and feed more freely. This is theeffect of a spate--which is, after all, only a dose of earth--upon wildtrout. 

The mould should be mixed with water in a bucket, and, when the water isvery thick and muddy, poured into the rearing boxes. The water in therearing boxes should be so thick that neither the bottom nor the youngfish, except when they come to the surface to take some passing particleof food, can be seen. The amateur should not wait till something goeswrong before giving this dose of earth; it is advisable to give it oncea week at any rate, and oftener if the fish seem to be ailing in anyway. 

In dealing with the subject of food for the young fish, I would begin byimpressing upon my reader that the greater variety of food he can givethe better it will be for the fish. He should also give them, at anyrate after they have been feeding some weeks, a certain proportion ofnatural food. Probably the best of all food for the fry is poundedshrimps or other crustaceans. It is, however, difficult in the veryearly stages of the trout's life to pound shrimps up small enough, andthe little fish are much given to trying to swallow pieces of food whichare too large for them to manage. This evil proclivity often causes thedeath of the fry, and therefore great care must be taken that no piecesof food which are too large, get into the rearing box. Pounded livershaken up in a bottle with water, and after the larger particles havebeen allowed to settle at the bottom, poured into the rearing box insmall quantities, is a good form of food for the alevins when they firstbegin to feed. The yolks of eggs boiled for about half an hour andpounded up, dog biscuit very finely pounded, or the fine food suppliedby several of the fish cultural establishments are also excellent. Ingiving moist food such as pounded shrimps, liver, meat, or the yolks ofeggs, a good plan while the fry are very small is to put the food in asmall net made of fine muslin mounted on a wire ring, and dipping theend of this net into the water, allow small particles to escape throughthe muslin. This ensures no large pieces getting into the rearing boxes. As the fry grow larger, these precautions are of course modified, as thelittle fish are capable of swallowing larger pieces of food. 

With regard to natural food, the amateur should take care to ensure agood stock for the young fish. Many of the creatures suitable for foodmay be cultivated in separate ponds at the same time as the fish, if anatural supply is not at hand. The _Daphnia pulex_ (water flea) and the_Cyclops quadricornis_ may be introduced into the boxes very soon afterthe fish have began to feed. _Daphnia_ breeds at the rate which isalmost inconceivable. The female produces her first brood of young whenshe is ten days old, and goes on breeding at an average of three or fourtimes a month. The female and her progeny are rendered fertile by oneact of coition, probably for fifteen generations at least, without anyfurther intervention of the male. Both _Daphnia_ and _Cyclops_ are bredin stagnant water in which there should be a good stock of weeds. 

The fresh water shrimp (_Gammarus pulex_) is an excellent form of foodfor young and old trout, and should be given to the fry as soon as theyare old enough to manage them. _Corixæ_ and other small insects shouldalso be given as often as possible. The fresh-water shrimp is bred inrunning water, _Corixæ_ in still or slow running water. Weeds arenecessary to the well-being of both. 

The boxes must be kept carefully covered, as I have already pointed out. A kingfisher would make short work of a box of fry, and other birds andbeasts of various kinds are partial to them. There are only two coursesopen to the fish culturist in dealing with these enemies--to protect hisfish or kill the enemies. I prefer to protect the fish first and killthe enemies afterwards. 

The greatest care must be taken not to introduce, or allow to intrude, any water beetles or the larger carnivorous aquatic larvæ of insects, into the rearing boxes. I have known cases where the larvæ of the_Dytiscus marginalis_, the largest of our carnivorous water beetles, have destroyed almost all the fry in a rearing pond. The adult _D. Marginalis_ itself is not a whit less voracious, and much stronger thanits larva. 

If the wooden parts of the apparatus have been properly prepared, according to my previous instructions, there should be no risk of thefry developing fungus. Quite a small spot of woodwork, however, leftuncovered by asphalt-varnish, or enamel, or uncharred, will render thechance of the development of this disease probable. 

Should by any misfortune fungus get into the rearing boxes, a dose ofsalt may very likely cure it. Sea water is the best, but if this is notobtainable, a solution of salt and water run through the boxes willprobably cure the disease. Considerable good may also be done to theyoung fish by occasionally putting a lump of rock salt in at the inlet, and the water allowed to run over and dissolve it. 

CHAPTER VIII

TROUT. THE MANAGEMENT OF THE FRY (_Continued_)

In the last chapter I brought my reader up to the point where the fry, which had been feeding for some time in the rearing boxes, had beenjudiciously separated, the weaker and smaller fish which took up theirpositions at the lower ends of the boxes having been put into separateboxes and induced as much as possible to keep at the head near to wherethe current enters. 

It is difficult to lay down any certain rule as to what is the best timeat which to take the next step--that of turning the fry out into therearing ponds. When the fry have got into more or less regular habits, and showing no fear of whoever it is who feeds them, come up readily andseize the food boldly, is probably the best time to let them out intothe larger space of the pond. I do not mean to say that when a certainproportion of the fish have got over their natural shyness, and feedboldly and without hesitation, the whole of them should be set free. What I mean is, that when the habit of associating the appearance of acertain individual with a meal has been well established among them fora week or so, they should be allowed to escape from the box into thepond. 

This is best done in the same way that the alevins were allowed toescape from the hatching tray into the box--by lowering the level of thebox so that its upper edges are some two or three inches below thesurface of the water. The food should now be thrown into the pond higherup, so that the little fish may be induced to swim up and stationthemselves as near the inlet as possible. Probably some of the littlefish will not leave the box at all of their own free will. These, ofcourse, will have to be turned out. The box should not, however, belifted out of the water and the fish and water together be poured out, as this is very likely to cause them severe injury. The box should begradually tilted over and lifted out of the water bottom first, so thatthe fish are hardly disturbed at all and certainly not injured in anyway. 

An important matter to consider before turning the little fish out intothe pond is, how the ponds are to be protected so that their manyenemies may be kept away from the fry. Kingfishers, herons, and othercreatures are very partial to young trout and will cause enormousdestruction if not prevented. Kingfishers have, in my experience, beenthe worst offenders. Some years ago I was rearing some trout in a partof the country where many of the inhabitants bewailed the exterminationof the kingfisher. Before I began rearing trout I agreed with thesepeople, for a kingfisher flitting along a stream looking like a littlemass of jewels is a pleasing sight, and one which I had never enjoyed inthat particular part of the country. 

When the time came to set my little fish free in the rearing ponds, as amatter of principle I covered the ponds with herring-net, closely peggeddown on the banks so that I could not even get my hand under the edge. Idid not think that there were any kingfishers or herons about, and sowas very surprised when one morning, on going down to feed the fish, Ifound a kingfisher under the net, flying up and down the pond trying toget out. By carefully introducing a landing-net under the netting overthe pond, I was able to catch the intruder, and caught four more in thesame way in about three weeks. Since that time I have not agreed withthe people who have stated that the kingfisher is almost extinct, atleast in that part of the country. I may say that there are but fewstreams there, and that it is not at all an apparently likely place forkingfishers. I am quite sure that wherever any one begins to rear fishthere he will find that kingfishers are fairly common. The amateur willprobably be also surprised at the way herons appear, if he conducts hisfish-rearing operations, as he should do, in a secluded spot. 

Many of the directions I gave as to the management of the fry and therearing boxes, apply also to the fry after they have been turned outinto the ponds. The doses of earth should still be given regularly, andsalt may be applied also in the way I have already described. The littlefish will be found to scatter over the pond or to divide again into twobodies, one at the upper and one at the lower end of the pond, as theydid in the boxes. The fish culturist should try to induce these fish tocome to the head of the pond as much as possible. It is a good thing toplace some boards across the head of the pond to give shade and shelterto the fry. It will probably be found that if much artificial food isgiven to the little fish, a scum will be formed on the surface of thewater. This scum is composed of grease, and should be removed, as soonas it is observed, with a gauze net. 

All the time that these operations have been going on with regard to thelittle fish themselves, due attention should have been given to thevegetation round the ponds. The alders and willows which I beforerecommended to be planted round the ponds should be induced as much aspossible to overhang the water. Grass and other vegetation should beallowed to grow freely round the margins, as many insects are thenlikely to fall into the water. 

This vegetation will supply the little fish with a certain amount ofnatural floating food, without any interference on the part of the fishculturist; but he should, however, give them other floating food, bothnatural and artificial, as much as possible, for this will get them intheir youth to adopt the habit of feeding freely at the surface. Whenthe alders and willows have grown sufficiently and are well covered withleaves, they will probably give enough shelter to the fish to make theboards at the upper end of the pond unnecessary. 

As time goes on, and the little fish grow, they should be thinned out, the smaller and weaker being removed into another pond. Despite the bestendeavours of the fish culturist, a certain number of these small fishare sure to keep to the lower end of the pond, and it is these whichshould be removed first. If they are left, the difference in sizebetween the smaller and the larger will soon become so great that thelarge fish will very likely be tempted to eat the small ones, thusdeveloping a cannibalistic habit which they will keep always. 

At the end of August or the beginning of September the little fish willhave got over the most dangerous part of their lives. After this timethey are called yearlings, are much more hardy and not subject to nearlyas many risks as up to that time. 

The great points to remember are:--That the food should be varied asmuch as possible; and as much natural food, of a hard description suchas shrimps, _corixæ_, snails, bivalves, etc. , be given. That the littlefish should be well protected from enemies. That they should not beover-crowded, but the weakly and small fish be separated from the largerfish. That frequent doses of earth should be given to keep the bottomsweet and clean. [2] That the inlets and outlets should be frequentlycleaned and kept clear, to ensure a good flow of water through theponds, and that a careful watch should be kept for such misfortunes asfungus and dead fish, in order that they may be dealt with at once. 

[2] See two letters in Appendix. --Page 93

CHAPTER IX

TROUT. THE FRIENDS AND ENEMIES OF THE FISH CULTURIST

The creatures which are sometimes found in and around rearing pondscontaining ova or young fish are very numerous, and it is advisable thatthe fish culturist should have some knowledge of them. It is for thisreason, that while I cautioned my readers against the creatures whichare dangerous, and enumerated some of those most serviceable as food, Ileft detailed descriptions of these enemies and friends of the littlefish, in order that I might deal with them in a separate chapter. 

[Illustration: LARVA OF _DYTISCUS_ AND YOUNG TROUT. ]

Among the worst enemies of both ova and fry is the _Dytiscusmarginalis_, whether this insect be in the larval or adult stage. Ithink that I should hardly be wrong in going even further and sayingthat _D. Marginalis_ is very dangerous to trout early in their yearlingstage. The accompanying illustration shows a larva of _Dytiscus_which has caught a young trout. This illustration is taken from aphotograph of a specimen lent to me by Mr. F. M. Halford, and both thefish and the larva were alive when they were caught. Unfortunately thetrout is a little shrivelled, and the legs of the _Dytiscus_ have beenbroken. _D. Marginalis_ lays its eggs in the stems of rushes. The larva, when hatched, makes its way out, and proceeds to lead a predatory life. The larva when full-grown is about two inches long, and is quite themost rapacious creature which lives in our waters. The adult beetle isalso purely carnivorous, but is perhaps not quite so rapacious. Itwould, however, probably attack a larger fish. 

The largest of English water beetles is _Hydrophilus piceus_. Thisbeetle is not, in the adult stage at least, carnivorous, but the larva, which is about half an inch longer and considerably fatter than that of_D. Marginalis_, is carnivorous. It may be told from the larva of_Dytiscus_ not only by its size, which is hardly a reliable point fordiscrimination, but by the smaller size of the head in comparison to therest of the body. The claws, with which _Hydrophilus_ seizes its prey, are, too, considerably smaller than those of _Dytiscus_. This larvashould be kept out of the rearing ponds with just as much care as thatof the more voracious _D. Marginalis_. 

With the kingfisher I have already dealt at some length, so that I needsay but little more with regard to it. One of the worst features in thisbird's character is that it will go on killing many more little fishthan it can possibly eat. As I have before said, it is surprising howthese birds will appear in considerable numbers where a fish hatchery isstarted, even in localities where they have before been considered rare. I have already described how the ponds should be protected from theirravages. 

Herons do a great deal of harm to fish ponds, even when the fish havegot well into the yearling stage. I have on one or two occasions knownof herons wounding trout of at least a pound in weight. Besides theactual damage they do by killing fish, they put all the other fish inthe pond off their feed through frightening them. After a heron orkingfisher has been about a rearing pond the little fish will not feedfor a considerable time, sometimes even for days. Notwithstanding theirvery evil proclivities, both herons and kingfishers are veryinteresting. A kingfisher, if he catches a fish which is a little toobig for him to swallow whole, will knock the head of the fish, which healways catches by the middle of the body, against a stone, in order tokill it, or at least to stop it struggling; it might otherwise in itsstruggles escape, as the kingfisher can only swallow a fish head first. There are stories which tell how herons sometimes pluck small feathersfrom their breasts and, floating these feathers upon the water, catchthe trout as they rise to it; it is supposed that the trout takes thefeather for a fly. Personally, I do not think that much credence shouldbe attached to the latter story. 

Other birds, usually found on or near the water, are also likely to domuch harm to the ova and young fish. Almost every creature which isfound near the water seems to have a great liking for the ova of fishes. All the wading and swimming birds are to be dreaded by the fishculturist. They will, all of them, eat ova in enormous quantities, andmany of them will also eat the little fish. 

Besides birds, small larvæ of several insects will eat, or at any ratekill, the ova in considerable numbers. Caddis-worms are among theselarvæ which eat ova. This seems to be one of the few cases in whichnature is just, for caddis-worms are taken very readily by even smalltrout. Large trout will take them very greedily, cases and all. Therefore, I should advise the fish culturist to cultivate them as foodfor the fish he is rearing, but to be very careful that they do not getinto the rearing boxes or hatching trays when he has ova in them. Thecaddis-worms kill the ova by making a small hole in them and suckingsome of the contents out; from this hole some more of the contentsescapes, and as it comes into contact with the water becomes opaque. 

Caddis-worms are the larvæ of an order of four-winged flies commonlyknown as sedges, caddis-flies, or water-moths. The latter appellation isof course a misnomer, as these flies (_Trichoptera_) have nothingwhatever to do with moths. They resemble moths, however, in that theyhave four wings which when at rest lie in much the same position as dothose of moths, and as many of them have their wings thickly coveredwith hairs, this resemblance is sometimes very marked. The larvæ(caddis-worms), being eagerly sought as food by many fish, and havingvery soft bodies, make for themselves cases. Some of these cases aremade from small sticks, some from little pieces of stone or sand, andsome from a mixture of all of these substances. As these cases resemblesuch small pieces of rubbish as are frequently found in streams, careshould be taken that they do not get into the hatching trays containingova. 

Many of the water beetles, and practically all of their larvæ, willattack the ova; they should therefore be carefully excluded from thehatching trays. As there are about 114 different species of beetles inthe family of _Dytiscidæ_ alone, my readers will appreciate my reasonfor not attempting to enumerate them. It will be a sufficient warning tostate the fact that they are all carnivorous, and their relative sizesis the only thing which will decide whether the beetle will eat thefish, or the fish the beetle. 

Very similar to beetles are some of the water-bugs. They may, however, easily be distinguished from beetles, as the outer or anterior wings ofthe bugs cross each other at their lower ends, while the elytra ofbeetles, which much resemble the horny, anterior wings of some of thewater-bugs, meet exactly in the middle line. These water-bugs, thoughsome of them are excellent food for even the small fish, will attack theova, and therefore they should be kept out of the hatching trays. Thefish culturist should, however, whenever it is possible, cultivate suchof these water-bugs as are good food for the fry in separate ponds, as Ihave before recommended. The best of these water-bugs are _Corixæ_. Others, such as the water-boatman, water-scorpions and pond-skaters, arenot of any value as food for the fish. 

The larvæ of _Ephemeridæ_ are very good food for the fish, and should becultivated in separate ponds if possible, and some turned into the pondscontaining the little fish occasionally. A fair proportion should, however, be kept in the ponds and protected, so that a good stock of theflies may be available next year. 

The larvæ of _Ephemeridæ_ may be obtained in many streams, and are bestcaught with a fine gauze net. Some of them swim, but most are generallycaptured with such a net at the bottom of the water among the _débris_. Eggs of _Ephemeridæ_ may be obtained sometimes from another locality ifthey cannot be got on the spot. These should be carefully preserved forthe first year at any rate, and a good fly may thus be introduced into awater where it was before unknown. 

I have already spoken of the fresh-water shrimp and the water-flea(_Daphnia pulex_). These valuable articles of diet should be introducedwhenever it is possible. _Daphnia_ must be reared in a stagnant pond, the fresh-water shrimp (_Gammarus pulex_) in running water, with plentyof weeds. 

Other useful creatures besides those snails and mussels which Idescribed in a previous chapter, are the water-louse (_Asellusaquaticus_), _Cypridæ_, and _Cyclops quadricornis_. Asellus is verysimilar in size and shape to the common garden-louse, which is found indecaying wood. It will live either in stagnant or running water. _Cypridæ_ are very much smaller, being generally only as large as alarge pin's head. They have a bivalve shell which makes them looksomething like a small mussel. They are, however, very active, swimmingby means of two pairs of legs. They also possess two pairs of antennæand one eye. (The species belonging to the genus _Candona_ of the family_Cypridæ_, do not swim. ) _Cyclops_ is another very small crustacean, shaped like a large-headed club. It swims very actively, and, like the_Cypridæ_, is an excellent article of diet for very young fish. Boththese crustacea live in stagnant water, and must, therefore, be kept ina separate pond, whence they may be taken as required to be given to thefry. 

CHAPTER X

TROUT. MANAGEMENT, FEEDING, AND TURNING OUT OF YEARLINGS

As I pointed out to my readers in Chapter VIII. , the young trout haveafter August passed the critical period of their existence, and may beconsidered safe and hardy. Naturally, as they get older, they requiremore food, but this need not be given so frequently as the fish growolder. While it was necessary to feed the fry at least four times a day, it will be found quite sufficient if the fish in August are fed onlytwice during the twenty-four hours. I must here again impress upon myreader the importance of feeding the trout upon as natural a food aspossible. Their future well-being depends upon this, much more than isgenerally realized even by fish culturists. Of course, trout fedentirely upon soft food may turn out all right, particularly if they areturned out as very young yearlings, but it is better not to leaveanything to chance and make sure of being on the safe side. 

As was the case with the fry during the whole of the earlier part oftheir lives, the yearlings will divide into two more or less separatepacks, though the fish may have been separated several times before inorder to divide those which kept at the head from those which kept atthe lower end of the pond. Those trout at the lower end must be coaxedto the upper end as much as possible, care being taken when feeding thatall the fish get a fair share of food. Should any of the fish remainobstinately at the lower end, and those at the upper end outgrow them toa marked extent, the smaller ones must be again separated from thelarger. 

When, in September or October, the little fish have grown active andstrong, they may be turned out into the water they are to occupy for therest of their lives. There is really no reason why, if they arewell-grown and strong, they should not be turned out in August if thewater they have to be taken to is quite close to the rearing ponds, butif they have to be carried any distance, it is better to keep them inthe rearing ponds for a few weeks longer, till the weather gets coolenough to make it quite safe to allow for a possible delay in thetransit. 

The turning out of the fish requires some little care. I have seen fishwhich had been sent by rail, poured out with the water contained in thecans, in as hurried a manner as possible. Though of course it isimportant to get the fish out of the cans used for transport as soon asis compatible with safety; still, undue haste in this operation islikely to do much harm. Young fish of any kind require delicatehandling, and young trout particularly. The cans should, when possible, be partly emptied, and some water from that into which they are to beturned put into the can. This is of course not necessary if the rearingponds are supplied from the same source as the water into which the fishare turned. The cans should then be partially immersed in the water, andthe edges brought gradually below the surface. This allows the fish toswim out of the cans of their own accord, and the few which will not goout may be forced to do so by gently turning the can upside down. 

It is a very good thing to give each of the fish a dose of salt beforeturning them out, particularly if they have travelled any distance. Thisis easily managed by catching the fish, a few at a time, in alanding-net from the travelling can, and then, instead of putting themstraight into the water, putting them into a bucket of salt and waterfor a short time. Sea water is of course better if it is available. Thisdoes away with any risk of their developing fungus on the spots whichhave very likely got bruised during the journey. 

The yearlings are best taken from the rearing ponds by netting them. Anet which is more than broad enough to go across the rearing pond isnecessary. Too many should not be taken out at a time in each haul ofthe net, as they are thus more likely to be injured or dropped on theground. The amateur should not forget, that though the little fish willstand a good deal of moving about as long as they are in water, they arelikely to be killed, or at least severely injured, by a shock, particularly if that shock is sustained while they are out of the waterfor a second or two during their being moved from one place to another. 

If the amateur intends to keep any of his yearlings longer thanDecember, he will have to make a larger pond. This pond need not be along, narrow one like those in which the fry were kept. Though the fishof course still require a sufficient supply of well-aerated water, alarger pond without the same marked current through it will do perfectlywell. They must be well fed, and if any grow markedly bigger than therest these should be separated. If they are not well supplied with foodthey are very likely to try and eat each other, that is to say, thelargest will try to eat the smallest. 

CHAPTER XI

THE REARING OF THE RAINBOW TROUT, AMERICAN BROOK TROUT, AND CHAR

As the methods used in hatching out the ova and rearing the young fishare very similar in the case of different species of trout to those Ihave already described in dealing with the common trout (_Salmo fario_), I will confine myself to pointing out the most marked differences in thehabits of such species as are suitable to our waters, and which arelikely to be of use to the fish culturist. The salmon- or sea-trout willbe dealt with under salmon. 

First and foremost among the trout, excluding of course our own browntrout, I put the rainbow trout (_Salmo irideus_). There are severalvarieties of this species, but that which is now being so freelyintroduced into many waters in England is the McCloud River rainbow (_S. Irideus_, var. _shasta_). As I have before stated, the rainbow spawnslong after the _S. Fario_. It therefore will give the fly-fishermen goodsport after the season for the common trout is over. It is a very freefeeder, and grows more rapidly than our trout; great care must thereforebe taken to give it plenty of food. I would draw my readers' attentionparticularly to this fact as to the feeding and quick-growing qualitiesof the rainbow, for they make it, if possible, even more necessary thatthe water into which they are turned should contain a good supply offood than it was in the case of the common trout; though even in thecase of the common trout, this is quite the most important considerationin stocking a water with fish. 

Another advantage possessed by the rainbow is, that it is less liable tothe attacks of fungus than any other of the _Salmonidæ_. Though, ofcourse, this is not such an important consideration nowadays as it wouldhave been even a few years ago, still it is one which deserves someconsideration, particularly from the amateur. This freedom from fungusis very marked in the rainbow, for I know of a case where some dacesuffering from fungus were put into a rearing pond containing a fewrainbows. Though the dace died of the disease, the rainbows remainedhealthy and free from it. The amateur will probably receive the ova ofthe rainbow towards the end of April or during May. The ova should hatchout within a few days of their being received. 

A few years, I might almost say months ago, the great majority ofdisinterested persons, whose opinion was of any consequence, wereinclined to condemn the general introduction of this fish into ourwaters. I was, unfortunately, supposed to be among a certain class ofpeople who advocated the general introduction of this fish into all ourwaters indiscriminately. This, I have always said, was a veryshort-sighted policy, for, to begin with, the evidence at our disposalseems to show that the rainbow will never thrive in cold waters, and atthe best can only be expected to really thrive and spawn in the warmwaters in the south of England. I never advocated more for the rainbowthan that it should have a fair trial in waters where our own trout hadbeen tried and found not to be a success. Now, however, I in my turnstand a chance of being converted by converts from among the very peoplewho, a short time ago, were condemning me for holding too favourable anopinion of the fish in question. I am inclined to think that in thecase of a pond in the south, even when it is supplied by a good stream, the rainbow is the better fish with which to stock. I have been led tobelieve this, partly through my own experience, and partly on account ofthe opinion of Mr. Senior, for I consider his opinion on such a matterof the greatest possible value. 

Another point about the rainbow, which in many cases will recommend itparticularly to the amateur, is that though of course an abundant supplyof water is an advantage, it may be reared with a smaller supply. 

A fish which has been very freely introduced into British waters is theAmerican brook-trout (_Salvelinus fontinalis_). Though this fish is notreally a trout but a char I have included it among trout, because it isso very generally known to fishermen as the American brook-trout. The_fontinalis_, as it is commonly called by fish culturists, is a verysatisfactory fish to rear artificially, but there seems to be some doubtas to its suitability to British waters. It grows to a considerable sizeunder favourable conditions, and is one of the best of table fishes. Itis, however, undoubtedly one of the worst of cannibals among sportingfishes, and does not apparently rise freely to the fly when about twoyears old and older. 

The spawning season is extended over an even longer period than that ofour own brown trout, beginning, in its native country, in October, andsometimes lasting till March. It shows a very marked tendency, at anyrate in America, to go down to the sea, and in some parts of Canada iscalled a sea-trout. The fish are easy to rear, but I should recommendgreat caution with regard to their introduction into any waters inEngland. The remarks and instructions which I gave with regard to thecommon trout, apply also to the _fontinalis_, but I would lay particularstress upon the necessity of separating the fish, as soon as some growlarger than the rest. The only drawback to this fish, from the fishculturist's point of view, is that though a very free feeder, it is verydainty, sometimes refusing a particular kind of food for no apparentreason. As the spawning season is extended over such a considerableperiod of time, it is obvious that the amateur will be able to obtainthe ova, ready to hatch out, during a similarly lengthy period. 

A fish which I should very much like to see tried in England, is thecut-throat trout (_Salmo mykiss_). It is also known as the red-throattrout. I should think, from the description given in the report of theCommission of Fisheries, Game, and Forests for the State of New York, that it would do well in many of our waters. There are many varieties ofthis species of trout. The common name of them all is _Salmo mykiss_, the black-spotted trout of the Rocky Mountains. The cut-throat troutproper, so called from the red colour of its throat, is simply S. Mykiss, but there are many varieties described. Among these are theColumbia River trout (_S. Mykiss_, var. _clarkii_), the Lake Tahoe trout(_S. Mykiss_, var. _henshawi_), the Rio Grande trout (_S. Mykiss_, var. _spilurus_), and the Colorado River trout (_S. Mykiss_, var. _pleuriticus_). As these names show, the black-spotted trout has a verywide range and is found in what are totally different climates. I shouldvery much like to see the cut-throat and the Columbia River varietiestried in our waters, particularly the former, as they would probablysucceed in waters which are too cold for the rainbow, and might verylikely thrive where our own trout (_S. Fario_) is not a success. As itis found in climates which vary so much as do Alaska and California, itwould probably be easy to find one variety, if not two or three, whichwould thrive in England. It is a particularly fine trout, and theordinary maximum weight is five or six pounds, though some of thevarieties grow much larger. 

Char, proper, are not at all satisfactory fish to rear. They are verydelicate, and require much more care and attention than do any of thefish I have already described. From the very first period of theircoming under the care of the amateur fish culturist, that is to say, from the ova, just before hatching out, till they are yearlings, themortality among them will be much greater than in the case of any of thetrout. 

The two kinds of char, most commonly to be obtained by the amateur, arethe Alpine and the Windermere char. The ova of these fish will bereceived shortly before they are ready to hatch out, as was the casewith the trout ova. The amateur's difficulties will, however, beginalmost at once, for in the act of hatching out considerable mortalityamong the char often occurs. Trout almost invariably emerge from the eggtail first. As soon as the tail is free the little fish begins to moveit rapidly, using it as a propeller with which to swim about and thussoon works completely out of the egg. Occasionally, however, trouthatch out head first, and in these cases the young fish generally diesbefore it can set itself free from the coverings of the ovum. Bucklandobserved that the alevins of the char very frequently hatch out headfirst, and consequently that many of them die before they can workthemselves free from the eggs. If it were possible to have some oneconstantly watching the ova at the time that they are hatching out, itwould be possible to save a very large proportion of them, as they maybe very effectually helped out of the egg with a feather or softcamel's-hair brush; but this is, of course, quite impracticable, unlessthere is some one constantly watching the ova, as the delay of even afew minutes will mean the death of the fish. This peculiarity in thehatching out of the char has also been observed by Mr. J. J. Armistead, and I have been able to verify it personally. 

The mortality which occurs in the actual hatching out of the alevinsdoes not, however, by any means end the trouble which the fish culturisthas to encounter in the rearing of char. They require much morepersuasion and care when they begin to feed and throughout the whole ofthe summer. The percentage of deaths is always greater than in the caseof the trouts, not excluding the _fontinalis_, which is, as I havealready explained, not really a trout but a char. 

Though there must be some doubt as to its success, I should like to seea really serious attempt at introducing char into some deep and largeponds in the south of England. Char have been very successfully rearedin shallow water, which was certainly not kept at a particularly lowtemperature, so I see no reason why this fish should not do in some ofour more southern waters. One drawback to the chance of this attemptbeing made, however, is that the char cannot be considered as being afish which gives very good sport, and I very much doubt whether any oneis likely to try the experiment simply to find out whether they would orwould not succeed in the south of England. 

CHAPTER XII

SALMON AND SEA-TROUT

In many ways nature is apparently very wasteful, and in nothing is thismore marked than in the case of the salmon. Probably not more than oneegg in a thousand produces a fish which reaches the smolt stage, and astill smaller proportion grows to the spawning stage. This greatmortality which occurs among the eggs and young fish when left to naturemay be very considerably reduced by artificial means, so that a veryfair proportion of the eggs deposited by the female fish will not onlybe hatched out successfully, but the little fish will reach the smoltstage safely and have a good chance of reaching the sea. How successfulartificial intervention may be has been proved over and over again inthe United States and in Canada. In the case of more than one river inCanada, the artificial propagation and protection of salmon has resultedin what is apparently the actual manufacture of a salmon river, yielding an annual haul of fish far beyond anything known in Europe, from a river which before yielded no salmon, or hardly any. 

These operations, carried out by the State, were of course far beyondanything which could be undertaken by the amateur, but I am sure that ifseveral riparian owners on a salmon river carried on artificial hatchingand rearing operations for several seasons, a marked increase in thenumber of fish in the river would ensue. The objection of most people tothis course is that it is unfortunately only too apparent that they arebenefiting chiefly, not the rod fisherman, but the netsman at the mouthof the river. 

The different artificial means used to help nature in producing a goodhead of salmon in a river vary chiefly in the amount of the help givenby each. It will suffice to say that the best is that which provides forthe protection and feeding of the young fish till it is ready to takeits first journey to the sea. The reason of this is obvious, as everyday passed in safety is a day gained, both in strength and in power ofself-preservation. 

Though it is possible to purchase a certain number of salmon ova, thisis not at all a satisfactory way of obtaining them. To begin with, it isimpossible to get them in sufficient numbers to carry out operations ona large enough scale. Salmon ova are also expensive; and it is no useworking with less than half a million in several stations if the riveris of any size. It is advisable that the ova should be obtained from thefish. This may be done either by collecting the ova deposited by thefish in the spawning beds or from the gravid females. The latter coursenecessitates the ripe female and male fish being caught and artificiallyspawned. As in nature, at best but a comparatively small percentage ofthe ova are impregnated, and by artificial spawning over ninety percent. Of them may be successfully hatched out, there can be but littledoubt as to which is the better way. It is difficult to make sure ofcatching the fish just at the time they are ripe, so it is advisable toimpound them in a fenced-off portion of the river, where they may be gotat easily. 

In the ripe female the ova flow out very readily, and but littlepressure is necessary. Hard pressure on the abdomen should never beapplied, as it is sure to injure the fish. A ripe female having beenobtained, from which the ova flow readily, the female is held over aperfectly clean tin or earthenware dish--wet, but containing nowater--and the ova are caused to flow into it by gently but firmlypressing the hand on the abdomen, and stroking it down towards the vent. Milt from a ripe male fish is then allowed to run over the ova in thedish, and is made to run well between them by tilting the dish aboutfrom side to side. The ova will now adhere together, and some watershould be added. This water should be poured off and fresh added tillthe superfluous milt is washed away, when the ova should be left in thewater till they separate, which will be in about twenty minutes or halfan hour. 

The fertilized ova thus obtained may either be laid down in artificiallyprotected hatching beds, or may be transferred to a hatchery. The latterproceeding, of course, requires a hatching house specially built andarranged, and as this is outside the scope of the present work, I wouldrefer my readers to larger works upon the subject, such as _An Angler'sParadise_, by J. J. Armistead. Of course, by using a hatchery a largenumber of the eggs will be saved, ninety per cent. Of them should hatchout. This is, therefore, obviously the best way to proceed. A very muchlarger number of eggs will, however, be hatched out in properly-chosenartificial beds than would be the case if they were left to nature. 

The necessary qualities of a good artificial bed are, a good supply ofclean water which is not liable if there is a spate to deposit sedimenton the eggs, protection from light, and protection from the manycreatures which prey upon the ova. The hatching beds may be so arrangedthat the young fish may escape as soon as they like after hatching out, but it is best to watch and protect them for at any rate the first fewweeks after they have begun to feed, and while continuing the feeding, to allow those of the fish that wish to escape. 

The rearing of young salmon and sea-trout is practically the same asthat of the common trout, except that they require more water. If keptin rearing ponds they grow more quickly than they do when left to findfood for themselves. While young, the salmon is marked with transversebars of a darker colour than the rest of the body. During the time itbears these marks it is known as a parr. [3] In about fifteen months itloses these marks and becomes quite silvery, being now known as a smolt. Shortly after assuming the smolt dress, the young salmon takes itsdeparture to the sea. In some cases the young salmon do not appear to godown to the sea till over two years after being hatched out, but theyshould always be set at liberty in March, April, or May in the yearfollowing that in which they were hatched out, according to how far theyhave developed the smolt or silver appearance. 

[3] All the trouts go through this stage, which is distinguished by"finger marks" upon the sides. 

If spring water is obtainable, particularly if the water, as is usuallythe case, is of an even temperature throughout the year, the troubles ofthe fish culturist are considerably lessened. Without a building for thehatching troughs it is almost impossible in many places to guard againstfrost unless such a spring is available. Sediment may be avoided byputting frames covered with flannel at the inlets to the hatching beds, these will, if kept clean, prevent any sediment from coming into theponds, and will allow plenty of water to flow in. If hatching trays arenot used, the bottom of the artificial bed should be covered with cleangravel. 

The time which elapses from the impregnation of the eggs to theirhatching out varies according to the temperature of the water, a fairlyaverage time is about ninety days. The ova should be watched during thistime, and the dead ones removed. For a short time after they areimpregnated they are fairly hardy, but from then till shortly beforethey hatch out the very slightest concussion will kill or seriouslyinjure them. 

The management of sea-trout ova is similar to that of salmon, and theova are obtained in the same way. As in the case of the salmon it isbest to rear the little fish artificially, till they are ready to godown to the sea; they will thus escape dangers likely to cause the lossof about eighty per cent. Of their number. 

The same methods and the same precautions as advised in the chapters onrearing trout should be adopted in the case of salmon and sea-trout asfar as is possible, and if this is done a very large percentage of theova should be successfully reared to the smolt stage. 

CHAPTER XIII

COARSE FISH

Compared to what is known about the early part of the life history ofthe _Salmonidæ_, our knowledge of coarse fish is small. Fortunately, however, such lengthy and complicated proceedings as are necessary toobtain a good stock of trout are not necessary to obtain a good stock ofcoarse fish. If even a few rudd, perch, dace, pike, or carp are put intowater where they have a good supply of food to begin with, and which issuitable otherwise for their well-being, the amateur's chief troubleafter a few years, if the water is not heavily fished, will be to keepdown the stock of coarse fish in proportion to the supply of food. 

I have seen many cases where rudd, perch, dace and carp have increasedto an enormous extent from a few fish introduced into the water. Somefour years ago we put a few small rudd into a mill-pond at home, thinking that the fry they produced would serve admirably as food to thetrout which also inhabited the pond. In about twenty months the pond wasfull of small rudd, and last year we netted out many hundred, as thewater was terribly over-stocked with them. The same thing has happenedin almost every case which has come to my knowledge; that is, of course, where the waters have been stocked with food, and suitable to the fishintroduced. 

The way in which dace will increase when put into a suitable water is, if possible, even more remarkable than what happens in the case of therudd. I will quote one instance, which proves this very conclusively. Afew years ago there were no dace in the Sussex Ouse. Pike fishermen, however, used to bring live dace to use as baits. Some of these escaped, or were set free by the fishermen at the end of their day's fishing, andnow the Sussex Ouse contains more dace for its size than any other riverI have ever seen. 

While rudd thrive best in a pond or lake into which a stream flows, dacerequire a river or stream to do well. They will, however, thrive andincrease rapidly in a river where trout are not a success. A muddybottom with occasional quickly running shallows, seem to constitute thebest kind of water for dace. The largest, and by far the bestconditioned dace I have seen, have come from the tidal parts of rivers, where the water is brackish at high water. Dace from such a water havealso the advantage of being very good eating, as they have, as a rule, not got the unpleasant muddy taste usual in this fish. 

Perch and pike will thrive both in rivers and in ponds or lakes whichhave a supply of water from a stream or from springs. They both increasein numbers very rapidly, and when protected, are more likely to requirethinning down every few years, than artificial assistance from theamateur. 

The king-carp is the best fish for the amateur who wishes to obtain goodbottom fishing from an absolutely stagnant pond. This fish is muchbolder and a more free feeder than the common carp. It increases sorapidly in numbers, and is a hard fighting and lively fish. 

Most of the coarse fish deposit a much larger number of eggs than do anyof the _Salmonidæ_--that is to say, in proportion to their size. Instocking a water which contains no fish, the amateur may wish to hurryon the process of nature in the case of coarse fish; and, fortunately, this is fairly easily managed. In the case of perch, rudd, pike, andcarp, but little change of water is required to hatch out the eggs. Theeggs of these fish take but a short time to hatch; and if they areprotected, and this protection is also given to the little fish for afew weeks, it will generally be found that an amply sufficient result isobtained. The eggs should be spread out carefully on wicker-work or thelids of baskets and kept in the light. A trickle of water which issufficient to change the body of water in the pond in which the ova areput will, as a rule, be enough. The amateur must be careful that thepond in which he hatches the eggs does not contain any of the manyenemies I have described in former chapters. If it is at all possible toprotect the eggs and the little fish, it is best to hatch out the eggsin the pond which it is intended to stock, for it is exceedinglydifficult to keep the newly-hatched fish in a rearing-pond on account oftheir very small size. It will be necessary to use muslin or flannelscreens instead of perforated zinc. Care must be taken that there is nottoo great a flow of water, as this will cause the little fish to bedrowned at the outlet screen. 

APPENDIX

THE USE OF EARTH IN REARING PONDS

[From a correspondence upon the subject which appeared in _Land andWater_]

SIR, --In your last issue I have read with pleasure the eminentlypractical notes on fish culture by Mr. Charles Walker. He is perfectlyright in all he says with reference to the useful and preventive resultsof the use of "common garden" earth, or vegetable mould in checking anyfungoid development, _Saprolegnia_ or other. It must, however, beadmitted that the said addition is not an element of beauty in a box;therefore it should be avoided, or only used when necessity dictates. However, the fry, when thoroughly restored to health, may be transferredby muslin net to another box free from earth should it be necessary tocount out certain numbers for the satisfaction of customers' orders. Again, the earth employed may, and in some waters does, give rise toother ill effects on the health of the "fry" or young fishes. Affectionof the eye is not unheard of as the result of over-use of earth. Perhapsthe best way to obviate any trouble of this nature would be to pound anddry the earth, and keep it in a canister or other closed vessel tillrequired for use. Spores of fungi are nearly, if not quite, omnipresent;and their effects are so insidious that too many precautions cannotwell be taken to avert the introduction of "trouble" in the hatchery. Indeed, were it not for the risks arising from attacks of fungi, pisciculture, as now understood and carried on, would be an unalloyedpleasure and unbounded success. We can practically hatch 995 out of1, 000 eggs, or thereabouts. It is the risks of rearing that stand in ourroad, and these, as time goes on, and experience increases, mustdiminish. There would appear, then, to be a good time coming for fishculture, and those who earnestly follow it. 

Practice is the only safe guide, as circumstances, geological, physical, and meteorological so vary the conditions of works that no definite ruleof procedure will avail. Earnest work and close observation, combinedwith ready resource, are the only safe guides to success. Troubles ofsome sort are sure to supervene; the man who succeeds is he who cananticipate, and so remedy them. To be always on the watch and notice thefirst indication is a very safe maxim, more easy to inculcate than toput in practice. 

There can be no question but that the practical removal of difficultiesin the path of fish culture is work of the highest value, well worthythe attention and acknowledgment of those in authority at Whitehall andelsewhere at home, as has been the case abroad. 

C. C. C. 

SIR, --Your correspondent "C. C. C. " in _Land and Water_ of last weekdisagrees with the constant and free use of earth, which I had advocatedin my article on fish culture which appeared the preceding week. Naturally one must admit that earth at the bottom of a pond is not sogreat an element of beauty as is clean gravel, but the advantages are somany, that beauty must give way to usefulness. Besides this, "C. C. C. "must know that it is almost impossible to keep the gravel clean enoughto look pretty, when the water is inhabited by a large number of littlefish which are being constantly fed. I cannot at all agree with hisadvice that "earth should be avoided, or only used when necessitydictates. " I believe that one of the first principles of success in fishculture is always to prevent any disease or mishap, rather than to waitfor, and then try to remedy it. Trout in their natural surroundings geta dose of earth every time that there is a spate. It is very evidentthat the earth contains some ingredients which are not only beneficialbut almost a necessity to the fish. 

I have never heard of earth as an actual cure for "fungus" and shouldhardly think that it is active enough. There is, however, no doubt thatit is one of the best preventatives to "fungus, " for if it is properlyand freely used it stops all chance of any decomposing material beingexposed to the action of the water, and laying the fish open to thechance of a great many evils. 

If suitable earth is used once a week, and even oftener on occasions, itcan do no harm, and will keep the fish safe from a great many risksbesides doing them very material good. I do not of course mean that theusual weekly dose should be a large one, as this would fill up the pondbefore the end of the season, but that a small dose should be givengenerally, and a large dose occasionally. I am quite sure, too, thatclean earth with some nice weeds growing in it, looks better than gravelwhich is dirty. Gravel shows the dirt so much, that it is almostimpossible to keep it looking nice where there are many fish, and italso gives the water free access to any decomposing matter. 

I have never come across a case of disease caused by the use of earth, and should like to hear the details of "C. C. C. 's" experiences withregard to this matter. 

CHARLES WALKER. 

INDEX

 Advantages of rainbow trout, 72-5

 Air bubble in yolk sac, 40

 Alders round rearing ponds, 32 at water side, importance of, 19

 Alevins, 39-41 diseases of, 40-1

 Alpine char, 78

 American brook trout, 15 rearing of, 75-6 spawning of, 76

 Aquatic creatures, serving as food for fish, 10-2, 62-6

 Aquatic plants suitable for deep water, 13 suitable for margins, 13

 Aquatic vegetation, importance of, 7 development of, 9

 Arrangement of rearing boxes, 34

 Artificial spawning of salmon, 83-4

 _Asellus aquaticus_, 65

 Black spotted trout of the Rocky Mountains, 76-8

 Blue swelling, 41

 Breeding char, difficulties in, 78-80

 Breeding. (See Rearing. )

 Brown trout, suitable water for, 14

 Bullrushes, 13

 _Byssus_, 37-8

 Caddis-worms, 61-3 in hatching trays, 38-9

 Carp, suitable water for, 18

 Char, 16, 78-80 Alpine, 78 difficulties in breeding, 78-80 hatching out of, 78-9 introduction of, to the south, 80 kinds of, 78 rearing, 79-80 suitable water for, 16 Windermere, 78

 Charring wood, importance of, 33, 50

 Chub, suitable water for, 18

 Coarse fish, 88-92 ova of, 90-1

 Colorado River trout, 77

 Columbia River trout, 77

 _Conchifera_, 12

 _Corixæ_, 10, 49, 63

 Covers for rearing ponds, 31

 Creatures, aquatic, serving as food for fish, 10-2, 61-6

 Crowfoot, water, 13

 Cure for fungus, 50

 Cut-throat trout, 76-8

 _Cyclops quadricornis_, 12, 48, 65-6

 _Cypridæ_, 65-6

 Dace, 18, 89-90 suitable water for, 18

 _Daphnia pulex_, 12, 48, 65

 Dead alevins, removal of, 41

 Dead ova, removal of, 37

 Difference between beetles and _Corixæ_, 11

 Diseases of alevins, 40-1 ova, 37-9

 _Dytiscus marginalis_, 11, 49, 58-60, 63

 Earth in rearing boxes, 46, 93-6 doses of, in rearing pond, 54, 93-6

 Effects of soft food on trout, 24

 _Ephemeridæ_, 12, 64-5 larvæ of, 64-5 catching larvæ of, 64

 Feeding of the fry, 42-9

 Feeding yearlings, 67

 Food, importance of, in waters, 5, 7

 Fresh-water shrimp, 10, 49, 65 snails, 10-2

 Friends and enemies of the fish, 58-66

 Fry, feeding of, 42-9 separating large from small, 45 turning out of rearing box, 51-2

 Fungus, 38-9 cure for, 50

 _Gammarus pulex_, 10, 49, 65

 Gold-fish, suitable water for, 18

 Grannom, introduction of, 12

 Grass round rearing ponds, 32

 Grayling, possible harm done by, to trout, 16 suitable water for, 17

 Great water moss, 13

 Hatchery, suitable spot for, 21-6

 Hatching out char, 78-9 ova of coarse fish, 91-2

 Hatching trays, arrangement of, 34 caddis-worms in, 38-9 construction of, 32 placing ova in, 34-6 removal of, 42-3 shrimps in, 36

 Herons, 60-1

 _Hydrophilus piceus_, 59-60

 Important points in rearing young trout, 56-7

 Inlet to rearing ponds, 29-30

 King carp, suitable water for, 18

 Kingfisher, 49, 53, 60

 Lake Tahoe trout, 77

 Lakewort, 13

 Leaf screen to rearing ponds, 29

 Lobelia, water, 13

 May fly, introduction of, 12

 Moss, great water, 13

 Mussels, 12

 _Nautonecta glauca_, 10, 64

 Natural food, importance of, 24 natural food for fry, 48-9

 Netting for rearing ponds, 31

 Ova beds, artificial salmon, 85

 Ova, care of, 36-9 dead, removal of, 37 hatching of, 39 of coarse fish, 90-1 of sea-trout, 87 placing in hatching trays, 34-6

 Perch, 19, 90-1 suitable water for, 19

 Pike, 18-9, 90-1

 Planting weeds in ponds, 7 in streams, 8

 Ponds for yearlings, 70-1

 Rainbow trout, 14-5, 72, 75 advantage of, 72-5 freedom from fungus, 73-4 rearing of, 72-5 suitable water for, 14 spawning time of, 21

 Rearing, important points in, 56-7

 Rearing box, arrangement of, 34 construction of, 31 cover for, 38, 49

 Rearing char, difficulties in, 79-80 fry of salmon, 85-7 fry of sea-trout, 85-7 rainbow trout, 72-5

 Rearing ponds, alders round, 32; grass round, 32 construction of, 22, 27-9 covers for, 31 gravel in, 23 importance of allowing water to run through for some weeks, 21 inlet to, 29-30 netting for, 31 pipes to, 22, 27 removal of yearlings from, 70 separating fish in, 54-6 size of, 23-4 use of earth in, 54, 56, 93-6 vegetation round, 33, 55 willows round, 32, 55

 Restocking, best time for, 24

 Rio Grande trout, 77

 Rudd, 17, 88-9, 91 suitable water for, 17

 _Salmo irideus_, 14-5, 72-5 _fario_, 15 _mykiss_, 76-8

 Salmon and sea-trout, 81-7

 Salmon, artificial spawning of, 83-4 artificial ova beds, 85 mortality among ova and young fish, 81 rearing fry, 85-7 scale upon which rearing should be carried out, 83 success in artificial intervention in stock of, 81-2

 Salt, as cure for fungus, 50 dose of, for yearlings, 69-70

 _Salvelinus fontinalis_, 15. (See American brook trout. )

 _Saprolegnia_, 38-9. (See Fungus. )

 Sea-trout, ova of, 87 rearing fry of, 85-7

 Sea-water as cure for fungus, 50

 Separating yearlings, 68

 Shrimp, fresh-water, 10, 49, 65

 Shrimps in hatching trays, 36

 Snails, fresh-water, 10-12

 Soft food, effects of, on trout, 24

 Spawning time of American brook trout, 76

 Stocking waters with food, 7

 Stonewort, water-, 13

 Suitable fish and suitable water, 14

 Trout, collecting wild ova of, 20 ova, management of, 20, 34-9

 Turning fry out of rearing box, 51-2 out yearlings, 68-9

 Varnishing wood, importance of, 33, 50

 Vegetation, aquatic, importance of, 7 aquatic, development of, 9 importance of, at water side, 19 on banks of water, 9, 19 round rearing ponds, 32, 55

 Water-boatman, 10, 64 beetles, 11, 58-60, 63 bugs, 63-4 celery, 13 cress, 13 crowfoot, 13 flea, 12, 48 lilies, 13 lobelia, 13 louse, 65 scorpion, 64 starwort, 13

 Weeds, importance of, in waters, 7 planting in ponds, 7 in streams, 8

 Willow round rearing ponds, 32, 55 at water side, 19

 Windermere char, 78

 Yearling trout, 56

 Yearlings, feeding of, 67 removal of, from rearing pond, 70 separating, 68 turning out, 68-9

Butler & Tanner, The Selwood Printing Works, Frome, and London. 

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