A greatly varying period of time having elapsed and the yolk-sacs of the alevins being nearly absorbed, the fish culturist will see that some of the little fish begin to leave the pack at the bottom of the tray, and to swim up against the current. When this is observed some very finely divided food should be offered to these alevins. They will probably dart at the minute pieces of food floating past and a little more may then be given to them. If, however, they do not take any notice of little pieces of food or any other matter which floats past them, they should not be tried again till the next day. In a few days from the first of the alevins beginning to feed, all of them will be working up with their heads 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 into the box.
As soon as the yolk-sacs of the alevins are absorbed the little fish cease to be alevins, and are called "fry."
The alevin stage was that in which the fish give least trouble, the stage I am now describing is that in which they give most. They must be fed frequently—at least four times a day. "Little and often" is the maxim which should rule the actions of the fish culturist with regard to feeding the fry. If he can only feed his fish four times a day, he must spend some time on each of these four occasions. The food must not be thrown in all at once. If this be done the little fish will not get half of it; the other half will sink to the bottom.
The food should be introduced in small quantities at a time, and if the amateur has several boxes he should put a little food into each in succession, 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 puts in at each time, and the oftener he does it, the better. The ideal plan would be to put a very small quantity of food in each time, and to go on doingthis at intervals of from five to ten minutes all day.
Livingstone Stone says, "You need not be afraid of the young fry's eating too much." And again, "I never knew any healthy young fry of mine decline eating but once, and then I had fed them incessantly for two hours, at the end of which time they gave up, beaten." Personally, I have found no limit to the time that the fry will continue feeding. I have kept on putting small quantities of food into a rearing box for a whole afternoon, and I was tired of feeding before the fry were tired of eating. My reader will infer from this that I believe that the fry cannot be over-fed, and this is to a certain extent true. If finely divided food is given in such small quantities that practically none of it sinks to the bottom without their having a fair chance at it, I believe that in a box containing only a couple of thousand fry, it would be found that they never stopped feeding during the whole day. If, however, too large pieces of food are offered to the little fish, many of them are likely to be choked and to die, from trying to swallow a piece a little too big for them.
The amateur will observe that shortly after thefry have been let out into the box and are feeding freely, they will separate into two more or less distinct groups. One at the upper end where the current comes in and is strongest, and one at the lower end. The fish at the upper end are the strongest and largest. This difference becomes more marked as time goes on, and in six or eight weeks after they have begun to feed the larger fish will be almost double the size of the smaller. In the middle of April, if many fry are in each box, they should be thinned out, and other boxes brought into use. The smaller fish may then be taken from one or two boxes and put into another by themselves. In feeding care should be taken that the small and weakly fish get a fair share of the food.
No matter how carefully the feeding is managed, some of the food is sure to 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 applied remedy for this evil exists in the use of mould dissolved in the water. Livingstone Stone recommends the mould under a sod, and I have always used this with the most beneficial effect. Earth, besides covering up and deodorizing the decomposing food atthe bottom, also contains some materials which are apparently necessary to the well-being of trout. To quote again from Livingstone Stone, who was the discoverer of this use of mould: "Earth or mud is the last thing one would suppose suitable for a fish so associated in our minds with pure, clean water; yet it is an indispensable constituent in the diet of young trout, and unless they get it, either naturally or artificially, they will not thrive."
The effect of earth given in this way upon the young fish is simply marvellous. They become more lively and feed more freely. This is the effect of a spate—which is, after all, only a dose of earth—upon wild trout.
The mould should be mixed with water in a bucket, and, when the water is very thick and muddy, poured into the rearing boxes. The water in the rearing boxes should be so thick that neither the bottom nor the young fish, except when they come to the surface to take some passing particle of food, can be seen. The amateur should not wait till something goes wrong before giving this dose of earth; it is advisable to give it once a week at any rate, and oftener if the fish seem to be ailing in any way.
In dealing with the subject of food for the young fish, I would begin by impressing upon my reader that the greater variety of food he can give the better it will be for the fish. He should also give them, at any rate after they have been feeding some weeks, a certain proportion of natural food. Probably the best of all food for the fry is pounded shrimps or other crustaceans. It is, however, difficult in the very early stages of the trout's life to pound shrimps up small enough, and the little fish are much given to trying to swallow pieces of food which are too large for them to manage. This evil proclivity often causes the death of the fry, and therefore great care must be taken that no pieces of food which are too large, get into the rearing box. Pounded liver shaken up in a bottle with water, and after the larger particles have been allowed to settle at the bottom, poured into the rearing box in small quantities, is a good form of food for the alevins when they first begin to feed. The yolks of eggs boiled for about half an hour and pounded up, dog biscuit very finely pounded, or the fine food supplied by several of the fish cultural establishments are also excellent. In giving moist food such as poundedshrimps, liver, meat, or the yolks of eggs, a good plan while the fry are very small is to put the food in a small net made of fine muslin mounted on a wire ring, and dipping the end of this net into the water, allow small particles to escape through the muslin. This ensures no large pieces getting into the rearing boxes. As the fry grow larger, these precautions are of course modified, as the little fish are capable of swallowing larger pieces of food.
With regard to natural food, the amateur should take care to ensure a good stock for the young fish. Many of the creatures suitable for food may be cultivated in separate ponds at the same time as the fish, if a natural supply is not at hand. TheDaphnia pulex(water flea) and theCyclops quadricornismay be introduced into the boxes very soon after the fish have began to feed.Daphniabreeds at the rate which is almost inconceivable. The female produces her first brood of young when she is ten days old, and goes on breeding at an average of three or four times a month. The female and her progeny are rendered fertile by one act of coition, probably for fifteen generations at least, without any further intervention of the male. BothDaphniaandCyclopsare bred in stagnant water in which there should be a good stock of weeds.
The fresh water shrimp (Gammarus pulex) is an excellent form of food for young and old trout, and should be given to the fry as soon as they are old enough to manage them.Corixæand other small insects should also be given as often as possible. The fresh-water shrimp is bred in running water,Corixæin still or slow running water. Weeds are necessary 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 and beasts of various kinds are partial to them. There are only two courses open to the fish culturist in dealing with these enemies—to protect his fish or kill the enemies. I prefer to protect the fish first and kill the 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 theDytiscus marginalis, the largest of our carnivorous water beetles, have destroyed almost all the fry in a rearing pond.The adultD. marginalisitself is not a whit less voracious, and much stronger than its larva.
If the wooden parts of the apparatus have been properly prepared, according to my previous instructions, there should be no risk of the fry developing fungus. Quite a small spot of woodwork, however, left uncovered by asphalt-varnish, or enamel, or uncharred, will render the chance of the development of this disease probable.
Should by any misfortune fungus get into the rearing boxes, a dose of salt may very likely cure it. Sea water is the best, but if this is not obtainable, a solution of salt and water run through the boxes will probably cure the disease. Considerable good may also be done to the young fish by occasionally putting a lump of rock salt in at the inlet, and the water allowed to run over and dissolve it.
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 been judiciously separated, the weaker and smaller fish which took up their positions at the lower ends of the boxes having been put into separate boxes and induced as much as possible to keep at the head near to where the current enters.
It is difficult to lay down any certain rule as to what is the best time at which to take the next step—that of turning the fry out into the rearing 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 and seize the food boldly, is probably the best time to let them out into the 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 feed boldly and without hesitation, the whole of them should be set free. What I mean is, that when the habit of associating the appearance of a certain individual with a meal has been well established among them for a week or so, they should be allowed to escape from the box into the pond.
This is best done in the same way that the alevins were allowed to escape from the hatching tray into the box—by lowering the level of the box so that its upper edges are some two or three inches below the surface of the water. The food should now be thrown into the pond higher up, so that the little fish may be induced to swim up and station themselves as near the inlet as possible. Probably some of the little fish will not leave the box at all of their own free will. These, of course, will have to be turned out. The box should not, however, be lifted 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 be gradually tilted over and lifted out of the water bottom first, so that the fish are hardly disturbed at all and certainly not injured in any way.
An important matter to consider before turning the little fish out into the pond is, how the ponds are to be protected so that their many enemies may be kept away from the fry. Kingfishers, herons, and other creatures are very partial to young trout and will cause enormous destruction if not prevented. Kingfishers have, in my experience, been the worst offenders. Some years ago I was rearing some trout in a part of the country where many of the inhabitants bewailed the extermination of the kingfisher. Before I began rearing trout I agreed with these people, for a kingfisher flitting along a stream looking like a little mass of jewels is a pleasing sight, and one which I had never enjoyed in that particular part of the country.
When the time came to set my little fish free in the rearing ponds, as a matter of principle I covered the ponds with herring-net, closely pegged down on the banks so that I could not even get my hand under the edge. I did not think that there were any kingfishers or herons about, and so was very surprised when one morning, on going down to feed the fish, I found a kingfisher under the net, flying up and down the pond trying to get out. By carefully introducing a landing-net under the netting over the pond, I was able to catch the intruder, and caught four more in the same way in about three weeks. Since that time I have not agreed with the people who have stated that the kingfisher is almost extinct, at least in that part of the country. I may say that there are but few streams there, and that it is not at all an apparently likely place for kingfishers. I am quite sure that wherever any one begins to rear fish there he will find that kingfishers are fairly common. The amateur will probably be also surprised at the way herons appear, if he conducts his fish-rearing operations, as he should do, in a secluded spot.
Many of the directions I gave as to the management of the fry and the rearing boxes, apply also to the fry after they have been turned out into the ponds. The doses of earth should still be given regularly, and salt may be applied also in the way I have already described. The little fish will be found to scatter over the pond or to divide again into two bodies, one at the upper and one at the lower end of the pond, as they did in the boxes. The fish culturist should try to induce these fish to come to the head ofthe pond as much as possible. It is a good thing to place some boards across the head of the pond to give shade and shelter to the fry. It will probably be found that if much artificial food is given to the little fish, a scum will be formed on the surface of the water. This scum is composed of grease, and should be removed, as soon as it is observed, with a gauze net.
All the time that these operations have been going on with regard to the little fish themselves, due attention should have been given to the vegetation round the ponds. The alders and willows which I before recommended to be planted round the ponds should be induced as much as possible to overhang the water. Grass and other vegetation should be allowed to grow freely round the margins, as many insects are then likely to fall into the water.
This vegetation will supply the little fish with a certain amount of natural floating food, without any interference on the part of the fish culturist; but he should, however, give them other floating food, both natural and artificial, as much as possible, for this will get them in their youth to adopt the habit of feeding freely at thesurface. When the alders and willows have grown sufficiently and are well covered with leaves, they will probably give enough shelter to the fish to make the boards 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 best endeavours of the fish culturist, a certain number of these small fish are sure to keep to the lower end of the pond, and it is these which should be removed first. If they are left, the difference in size between the smaller and the larger will soon become so great that the large fish will very likely be tempted to eat the small ones, thus developing a cannibalistic habit which they will keep always.
At the end of August or the beginning of September the little fish will have got over the most dangerous part of their lives. After this time they are called yearlings, are much more hardy and not subject to nearly as many risks as up to that time.
The great points to remember are:—That the food should be varied as much as possible; and as much natural food, of a hard description such as shrimps,corixæ, snails, bivalves, etc., be given.That the little fish should be well protected from enemies. That they should not be over-crowded, but the weakly and small fish be separated from the larger fish. That frequent doses of earth should be given to keep the bottom sweet and clean.[2]That the inlets and outlets should be frequently cleaned and kept clear, to ensure a good flow of water through the ponds, and that a careful watch should be kept for such misfortunes as fungus and dead fish, in order that they may be dealt with at once.
[2]See two letters in Appendix.—Page 93
[2]See two letters in Appendix.—Page 93
The creatures which are sometimes found in and around rearing ponds containing ova or young fish are very numerous, and it is advisable that the fish culturist should have some knowledge of them. It is for this reason, that while I cautioned my readers against the creatures which are dangerous, and enumerated some of those most serviceable as food, I left detailed descriptions of these enemies and friends of the little fish, in order that I might deal with them in a separate chapter.
LARVA OF DYTISCUS AND YOUNG TROUT.LARVA OFDYTISCUSAND YOUNG TROUT.
Among the worst enemies of both ova and fry is theDytiscus marginalis, whether this insect be in the larval or adult stage. I think that I should hardly be wrong in going even further and saying thatD. marginalisis very dangerous to trout early in their yearling stage. The accompanying illustration shows a larva ofDytiscuswhich has caught a young trout. This illustration is taken from a photograph of a specimen lent to me by Mr. F. M. Halford, and both the fish and the larva were alive when they were caught. Unfortunately the trout is a little shrivelled, and the legs of theDytiscushave been broken.D. marginalislays 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 the most rapacious creature which lives in our waters. The adult beetle is also purely carnivorous, but is perhaps not quite so rapacious. It would, however, probably attack a larger fish.
The largest of English water beetles isHydrophilus piceus. This beetle is not, in the adult stage at least, carnivorous, but the larva, which is about half an inch longer and considerably fatter than that ofD. marginalis, is carnivorous. It may be told from the larva ofDytiscusnot only by its size, which is hardly a reliable point for discrimination, but by the smaller size of the head in comparison to the rest of the body. The claws, with whichHydrophilusseizes its prey, are, too, considerably smaller than those ofDytiscus. This larva should be kept out of the rearing ponds with just as much care as that of the more voraciousD. marginalis.
With the kingfisher I have already dealt at some length, so that I need say but little more with regard to it. One of the worst features in this bird's character is that it will go on killing many more little fish than it can possibly eat. As I have before said, it is surprising how these birds will appear in considerable numbers where a fish hatchery is started, even in localities where they have before been considered rare. I have already described how the ponds should be protected from their ravages.
Herons do a great deal of harm to fish ponds, even when the fish have got well into the yearling stage. I have on one or two occasions known of herons wounding trout of at least a pound in weight. Besides the actual damage they do by killing fish, they put all the other fish in the pond off their feed through frightening them. After a heron or kingfisher has been about a rearing pond the little fish will not feed for a considerable time, sometimes even for days. Notwithstanding their very evil proclivities, both herons and kingfishers are very interesting.A kingfisher, if he catches a fish which is a little too big for him to swallow whole, will knock the head of the fish, which he always catches by the middle of the body, against a stone, in order to kill it, or at least to stop it struggling; it might otherwise in its struggles escape, as the kingfisher can only swallow a fish head first. There are stories which tell how herons sometimes pluck small feathers from their breasts and, floating these feathers upon the water, catch the trout as they rise to it; it is supposed that the trout takes the feather for a fly. Personally, I do not think that much credence should be attached to the latter story.
Other birds, usually found on or near the water, are also likely to do much harm to the ova and young fish. Almost every creature which is found 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 fish culturist. They will, all of them, eat ova in enormous quantities, and many of them will also eat the little fish.
Besides birds, small larvæ of several insects will eat, or at any rate kill, the ova in considerable numbers. Caddis-worms are among theselarvæ which eat ova. This seems to be one of the few cases in which nature is just, for caddis-worms are taken very readily by even small trout. Large trout will take them very greedily, cases and all. Therefore, I should advise the fish culturist to cultivate them as food for the fish he is rearing, but to be very careful that they do not get into the rearing boxes or hatching trays when he has ova in them. The caddis-worms kill the ova by making a small hole in them and sucking some of the contents out; from this hole some more of the contents escapes, and as it comes into contact with the water becomes opaque.
Caddis-worms are the larvæ of an order of four-winged flies commonly known as sedges, caddis-flies, or water-moths. The latter appellation is of course a misnomer, as these flies (Trichoptera) have nothing whatever to do with moths. They resemble moths, however, in that they have four wings which when at rest lie in much the same position as do those of moths, and as many of them have their wings thickly covered with 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 are made from small sticks, some from little pieces of stone or sand, and some from a mixture of all of these substances. As these cases resemble such small pieces of rubbish as are frequently found in streams, care should be taken that they do not get into the hatching trays containing ova.
Many of the water beetles, and practically all of their larvæ, will attack the ova; they should therefore be carefully excluded from the hatching trays. As there are about 114 different species of beetles in the family ofDytiscidæalone, my readers will appreciate my reason for not attempting to enumerate them. It will be a sufficient warning to state the fact that they are all carnivorous, and their relative sizes is the only thing which will decide whether the beetle will eat the fish, 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 of the bugs cross each other at their lower ends, while the elytra of beetles, which much resemble the horny, anterior wings of some of the water-bugs, meet exactly in the middle line.These water-bugs, though some of them are excellent food for even the small fish, will attack the ova, and therefore they should be kept out of the hatching trays. The fish culturist should, however, whenever it is possible, cultivate such of these water-bugs as are good food for the fry in separate ponds, as I have before recommended. The best of these water-bugs areCorixæ. Others, such as the water-boatman, water-scorpions and pond-skaters, are not of any value as food for the fish.
The larvæ ofEphemeridæare very good food for the fish, and should be cultivated in separate ponds if possible, and some turned into the ponds containing the little fish occasionally. A fair proportion should, however, be kept in the ponds and protected, so that a good stock of the flies may be available next year.
The larvæ ofEphemeridæmay be obtained in many streams, and are best caught with a fine gauze net. Some of them swim, but most are generally captured with such a net at the bottom of the water among thedébris. Eggs ofEphemeridæmay be obtained sometimes from another locality if they cannot be got on thespot. These should be carefully preserved for the first year at any rate, and a good fly may thus be introduced into a water 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 introduced whenever it is possible.Daphniamust be reared in a stagnant pond, the fresh-water shrimp (Gammarus pulex) in running water, with plenty of weeds.
Other useful creatures besides those snails and mussels which I described in a previous chapter, are the water-louse (Asellus aquaticus),Cypridæ, andCyclops quadricornis. Asellus is very similar in size and shape to the common garden-louse, which is found in decaying wood. It will live either in stagnant or running water.Cypridæare very much smaller, being generally only as large as a large pin's head. They have a bivalve shell which makes them look something like a small mussel. They are, however, very active, swimming by means of two pairs of legs. They also possess two pairs of antennæ and one eye. (The species belonging to the genusCandonaof the familyCypridæ, do not swim.)Cyclopsis another very small crustacean, shaped like alarge-headed club. It swims very actively, and, like theCypridæ, is an excellent article of diet for very young fish. Both these crustacea live in stagnant water, and must, therefore, be kept in a separate pond, whence they may be taken as required to be given to the fry.
As I pointed out to my readers inChapter VIII., the young trout have after August passed the critical period of their existence, and may be considered safe and hardy. Naturally, as they get older, they require more food, but this need not be given so frequently as the fish grow older. 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 only twice during the twenty-four hours. I must here again impress upon my reader the importance of feeding the trout upon as natural a food as possible. Their future well-being depends upon this, much more than is generally realized even by fish culturists. Of course, trout fed entirely upon soft food may turn out all right, particularly if they are turned out as very young yearlings,but it is better not to leave anything 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 of their lives, the yearlings will divide into two more or less separate packs, though the fish may have been separated several times before in order to divide those which kept at the head from those which kept at the lower end of the pond. Those trout at the lower end must be coaxed to the upper end as much as possible, care being taken when feeding that all the fish get a fair share of food. Should any of the fish remain obstinately at the lower end, and those at the upper end outgrow them to a marked extent, the smaller ones must be again separated from the larger.
When, in September or October, the little fish have grown active and strong, they may be turned out into the water they are to occupy for the rest of their lives. There is really no reason why, if they are well-grown and strong, they should not be turned out in August if the water they have to be taken to is quite close to the rearing ponds, but if they have to be carried any distance, it is better to keep them in the rearing ponds for a few weeks longer, till theweather gets cool enough to make it quite safe to allow for a possible delay in the transit.
The turning out of the fish requires some little care. I have seen fish which had been sent by rail, poured out with the water contained in the cans, in as hurried a manner as possible. Though of course it is important to get the fish out of the cans used for transport as soon as is compatible with safety; still, undue haste in this operation is likely to do much harm. Young fish of any kind require delicate handling, and young trout particularly. The cans should, when possible, be partly emptied, and some water from that into which they are to be turned put into the can. This is of course not necessary if the rearing ponds are supplied from the same source as the water into which the fish are turned. The cans should then be partially immersed in the water, and the edges brought gradually below the surface. This allows the fish to swim out of the cans of their own accord, and the few which will not go out 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 before turning them out, particularly if they have travelled any distance. This is easilymanaged by catching the fish, a few at a time, in a landing-net from the travelling can, and then, instead of putting them straight into the water, putting them into a bucket of salt and water for a short time. Sea water is of course better if it is available. This does away with any risk of their developing fungus on the spots which have very likely got bruised during the journey.
The yearlings are best taken from the rearing ponds by netting them. A net which is more than broad enough to go across the rearing pond is necessary. Too many should not be taken out at a time in each haul of the net, as they are thus more likely to be injured or dropped on the ground. The amateur should not forget, that though the little fish will stand a good deal of moving about as long as they are in water, they are likely to be killed, or at least severely injured, by a shock, particularly if that shock is sustained while they are out of the water for a second or two during their being moved from one place to another.
If the amateur intends to keep any of his yearlings longer than December, 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 fish of course still require a sufficient supply of well-aerated water, a larger pond without the same marked current through it will do perfectly well. They must be well fed, and if any grow markedly bigger than the rest these should be separated. If they are not well supplied with food they are very likely to try and eat each other, that is to say, the largest will try to eat the smallest.
As the methods used in hatching out the ova and rearing the young fish are very similar in the case of different species of trout to those I have already described in dealing with the common trout (Salmo fario), I will confine myself to pointing out the most marked differences in the habits of such species as are suitable to our waters, and which are likely to be of use to the fish culturist. The salmon- or sea-trout will be dealt with under salmon.
First and foremost among the trout, excluding of course our own brown trout, I put the rainbow trout (Salmo irideus). There are several varieties of this species, but that which is now being so freely introduced into many waters in England is the McCloud River rainbow (S. irideus, var.shasta). As I have before stated, the rainbow spawns long after theS. fario. It therefore will give the fly-fishermen good sport after the season for the common trout is over. It is a very free feeder, and grows more rapidly than our trout; great care must therefore be taken to give it plenty of food. I would draw my readers' attention particularly to this fact as to the feeding and quick-growing qualities of the rainbow, for they make it, if possible, even more necessary that the water into which they are turned should contain a good supply of food than it was in the case of the common trout; though even in the case of the common trout, this is quite the most important consideration in stocking a water with fish.
Another advantage possessed by the rainbow is, that it is less liable to the attacks of fungus than any other of theSalmonidæ. Though, of course, this is not such an important consideration nowadays as it would have been even a few years ago, still it is one which deserves some consideration, particularly from the amateur. This freedom from fungus is very marked in the rainbow, for I know of a case where some dace suffering from fungus were put into a rearing pond containing a few rainbows. Though the dace died of the disease, the rainbows remained healthy and freefrom it. The amateur will probably receive the ova of the rainbow towards the end of April or during May. The ova should hatch out within a few days of their being received.
A few years, I might almost say months ago, the great majority of disinterested persons, whose opinion was of any consequence, were inclined to condemn the general introduction of this fish into our waters. I was, unfortunately, supposed to be among a certain class of people who advocated the general introduction of this fish into all our waters indiscriminately. This, I have always said, was a very short-sighted policy, for, to begin with, the evidence at our disposal seems to show that the rainbow will never thrive in cold waters, and at the best can only be expected to really thrive and spawn in the warm waters in the south of England. I never advocated more for the rainbow than that it should have a fair trial in waters where our own trout had been tried and found not to be a success. Now, however, I in my turn stand a chance of being converted by converts from among the very people who, a short time ago, were condemning me for holding too favourable an opinion of the fish in question. I am inclined to think that inthe case 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 to believe this, partly through my own experience, and partly on account of the opinion of Mr. Senior, for I consider his opinion on such a matter of the greatest possible value.
Another point about the rainbow, which in many cases will recommend it particularly to the amateur, is that though of course an abundant supply of water is an advantage, it may be reared with a smaller supply.
A fish which has been very freely introduced into British waters is the American brook-trout (Salvelinus fontinalis). Though this fish is not really a trout but a char I have included it among trout, because it is so very generally known to fishermen as the American brook-trout. Thefontinalis, as it is commonly called by fish culturists, is a very satisfactory fish to rear artificially, but there seems to be some doubt as to its suitability to British waters. It grows to a considerable size under favourable conditions, and is one of the best of table fishes. It is, however, undoubtedly one of the worst of cannibals among sporting fishes, and does not apparentlyrise freely to the fly when about two years old and older.
The spawning season is extended over an even longer period than that of our own brown trout, beginning, in its native country, in October, and sometimes lasting till March. It shows a very marked tendency, at any rate in America, to go down to the sea, and in some parts of Canada is called a sea-trout. The fish are easy to rear, but I should recommend great caution with regard to their introduction into any waters in England. The remarks and instructions which I gave with regard to the common trout, apply also to thefontinalis, but I would lay particular stress upon the necessity of separating the fish, as soon as some grow larger than the rest. The only drawback to this fish, from the fish culturist's point of view, is that though a very free feeder, it is very dainty, sometimes refusing a particular kind of food for no apparent reason. As the spawning season is extended over such a considerable period of time, it is obvious that the amateur will be able to obtain the ova, ready to hatch out, during a similarly lengthy period.
A fish which I should very much like to see tried in England, is the cut-throat trout (Salmomykiss). It is also known as the red-throat trout. I should think, from the description given in the report of the Commission 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 of this species of trout. The common name of them all isSalmo mykiss, the black-spotted trout of the Rocky Mountains. The cut-throat trout proper, so called from the red colour of its throat, is simply S. mykiss, but there are many varieties described. Among these are the Columbia 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 very wide range and is found in what are totally different climates. I should very much like to see the cut-throat and the Columbia River varieties tried in our waters, particularly the former, as they would probably succeed in waters which are too cold for the rainbow, and might very likely thrive where our own trout (S. fario) is not a success. As it is 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, which would thrive in England. It is a particularly fine trout, and the ordinary maximum weight is five or six pounds, though some of the varieties grow much larger.
Char, proper, are not at all satisfactory fish to rear. They are very delicate, and require much more care and attention than do any of the fish I have already described. From the very first period of their coming under the care of the amateur fish culturist, that is to say, from the ova, just before hatching out, till they are yearlings, the mortality among them will be much greater than in the case of any of the trout.
The two kinds of char, most commonly to be obtained by the amateur, are the Alpine and the Windermere char. The ova of these fish will be received shortly before they are ready to hatch out, as was the case with the trout ova. The amateur's difficulties will, however, begin almost at once, for in the act of hatching out considerable mortality among the char often occurs. Trout almost invariably emerge from the egg tail first. As soon as the tail is free the little fish begins to move it rapidly, using it as a propeller with which to swim about and thus soon works completely out of the egg. Occasionally, however, trout hatch out head first, and in these cases the young fish generally dies before it can set itself free from the coverings of the ovum. Buckland observed that the alevins of the char very frequently hatch out head first, and consequently that many of them die before they can work themselves free from the eggs. If it were possible to have some one constantly watching the ova at the time that they are hatching out, it would be possible to save a very large proportion of them, as they may be very effectually helped out of the egg with a feather or soft camel's-hair brush; but this is, of course, quite impracticable, unless there is some one constantly watching the ova, as the delay of even a few minutes will mean the death of the fish. This peculiarity in the hatching 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 alevins does not, however, by any means end the trouble which the fish culturist has to encounter in the rearing of char. They require much more persuasion and care when they begin to feed and throughout thewhole of the summer. The percentage of deaths is always greater than in the case of the trouts, not excluding thefontinalis, which is, as I have already explained, not really a trout but a char.
Though there must be some doubt as to its success, I should like to see a really serious attempt at introducing char into some deep and large ponds in the south of England. Char have been very successfully reared in shallow water, which was certainly not kept at a particularly low temperature, so I see no reason why this fish should not do in some of our more southern waters. One drawback to the chance of this attempt being made, however, is that the char cannot be considered as being a fish which gives very good sport, and I very much doubt whether any one is likely to try the experiment simply to find out whether they would or would not succeed in the south of England.