THE CULTIVATION OF COARSE FISH.

WITH A FEW NOTES ON ACCLIMATISATION.

[I am indebted to the courtesy of the Marquis of Exeter, and of Mr. R. B. Marston, editor of the Fishing Gazette for the following highly interesting and practical notes on the cultivation and acclimatisation of coarse fish 1-notably of the Black Bass, subjects in regard to which too little attention has been hitherto shown by the owners of ponds, lakes, canals, and other waters, unsuited to Salmon or Trout.

It is probable that many of such waters, if properly stocked and judiciously farmed, might prove a success from a market or commercial point of view; but in any case, as Mr. Marston truly points out in the essay which here follows, to do something for the healthy and wholesome recreation of the toiling thousands of our mills and factories should be in itself an object well worthy of the philanthropist and statesman.-H. C.-P.]

SOME anglers affect to look down upon coarse fish and the sport they afford. I confess I prefer fly-fishing for salmon, trout, and grayling, but that is not always obtainable, and then I am content with the next best fishing to be had, whether it be for pike, barbel, perch, chub, or roach, &c.

An amazing increase in the number of anglers has taken place within the last few years. This increase has been large

1 Lord Exeter's very successful experiments at Burghley House embrace Salmonida as well as Coarse fish.

among salmon, trout, and grayling fishers; it has been far greater among those who, not having the means or opportunity of fishing for the Salmonida, give their attention to our other freshwater species. A few years ago the angling clubs of London and the provinces could be counted by the dozen, now they number many hundreds with many thousands of members. But, while anglers have been increasing in this wonderful manner, the fish have been most certainly decreasing. The cry from the clubs is: How can we get fish?

Something must be done for these thousands upon thousands of anglers, for without fish their recreation is gone, and that they should be encouraged will be admitted by every one who gives the matter a moment's reflection. The larger portion of the coarse-fish anglers are working men and youths, mechanics, artizans, miners-toilers in our mills and factories in the great centres of industry-men to whom every inducement should be held out to attract them into fresh air and scenes in their spare time. How, then, is the decrease in those fish, in the capture of which they take such delight, to be stopped? and how can the thousands of miles of water which might yield them sport be replenished?

That these questions need answering at all proves that, in this country at least, very little has been done in the direction of cultivation of coarse fish, though, as a matter of fact, in the case of most of them it presents far less difficulty and expense than is attendant on the breeding of the Salmonida.

The first thing to be recognised is that, consequent on the great difference in the modes of spawning of the Salmonida and coarse fish, a widely different method must be adopted. Salmon, trout, and grayling eggs are non-adhesive, and each egg can thus be manipulated separately-they take months to hatch out. The eggs of the coarse fish are adhesive, making their manipulation extremely difficult-so much so, that while ninety-five per cent. of salmon and trout eggs can be hatched out, those who have attempted to treat coarse fish eggs in the same way have rarely succeeded in rearing even five per cent.

The eggs of the coarse fish hatch out in a very short time, a week or ten days being the average time required. If, then, we had to look to what is called artificial breeding to enable us to increase our coarse fish, the prospect would not be an encouraging one.

But, fortunately perhaps, artificial breeding is not necessary in the case of coarse fish; all we need do is to give nature a certain amount of aid, and she will do the rest for us. We must place the parent fish in suitable places for spawning, and then protect the eggs until the fry hatch out.

It is not only difficult, however, to manipulate the eggs in troughs and trays, but the difficulty of rearing the young fry is even greater still. They are hatched out as perfect fish, almost at once requiring extraneous food, and they are so extremely small that to feed them is a difficult matter. They appear to require that as soon as they leave the egg they should be able to seek their own sustenance on the almost invisible animalculæ present in their native waters.1

The diagram represents what is known in Sweden as Lund's hatching-box. It was invented more than a hundred years ago by a Mr. Lund, of Linköping. The Swedish inspector kindly furnished me with information about this box, which is in general use in Sweden. He says:-'Replying to your letter of the 25th of February, 1882, in which you request me to give you some particulars respecting Lund's hatching-box for the propagation of summer-spawning fish, I herewith hasten to give you all the information I can. Lund's apparatus is remarkable on account of its being, for aught I know, the first attempt in Europe to promote the propagation of the above-mentioned

1 The umbilical sac, on the contents of which the trout alevin exists for six weeks, lasts the alevin of the coarse fish but a day or two, and unless the young fish are fed they will die; hence the difficulty of rearing them in confinement. Mr. Kelson, of Oxford, last year made the valuable discovery that the animalculæ bred in water containing decayed vegetable matter (like that in which cut flowers have been kept some time) are eagerly devoured by the young fry. I think it is difficult to over-rate the value of this discovery to the breeder of coarse fish.-R. B. M.

fish with human assistance. As you rightly suppose, the box is to be placed in shallow water near the bank, so that the water does not flow over it. Lund has not given any dimensions for his box, which may be of any size. The sides are hinged, so that they can be let down, and they are perforated with numerous small holes, so that the water can circulate through. The inside should be charred by fire to preserve

it. The bottom of the box and the sides are lined with fir branches. As you will see from the sketch I send you, the box should stand on blocks, so as to be raised a little from the bed of the water. With some modifications-for instance, it is not necessary to have the sides hinged-Lund's box has been adopted here in Sweden with success, and, in my opinion, for the hatching of perch, it is the most practical that has yet been invented. In a box of this kind, six feet square, and with sides two feet high, we place fifty female and from twenty to thirty male fish. These fish must be placed in the hatching-box as

near their spawning time as possible, and are taken out again as soon as the spawning is finished. The fish deposit the spawn on the branches. It is of great importance that the sides be well perforated, to ensure free circulation of the water. We use these boxes chiefly for perch, but they can also be used, with some modifications, for other fish.'

It is an easy matter to transport spawn which has been obtained in this way to almost any distance, as it adheres to the boughs; so that you can either let the fry develop in the box, and then go free in the water you desire to stock, or you can carry the fertilised spawn to some place, perhaps a hundred miles away, and then place it in a similar box in the water you desire to stock. In a week or ten days' time the fry will hatch out in countless numbers, and must then be liberated and allowed to begin their fight for life alone. In the Swedish exhibit in the Fisheries Exhibition, some models of Lund's box were displayed. These models were exhibited in the Berlin International Fisheries Exhibition, and are thus referred to, in the German Official Report on that Exhibition, by Dr. Haack, director of the great fish-breeding establishment at Huningue.

In dealing with the Swedish exhibit he says:-'In the Swedish exhibit there were two insignificant-looking models, which were quite overlooked by the majority of visitors, but which were of the very greatest interest to every thinking pisciculturist. These models, in spite of their simplicity and insignificance, show us the way we, in future, most simply, easily, and inexpensively may carry on the propagation of our summerspawning fish to any extent.' He then describes the manner in which the box is used, and refers to its advantages as follows:'As will be evident to every one, the eggs which have been deposited and impregnated in the box develop in a perfectly natural manner . . . air, light, and sun are able to exert their influences on the eggs in exactly the same way as if they had been deposited on water-plants in the open water in the ordinary way. Wind and waves can in like manner exert their beneficial influence on the eggs, which at the same time are protected

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