A brief summary of the chief points in the habits of these mysterious fish may interest the reader. The “vendiss,” as it is locally called, occurs nowhere but in the waters at Lochmaben, in Dumfriesshire; and it is thought by the general run of the country people to be, like the powan of Lochlomond, a fresh-water herring. The history of this fish is quite unknown, but it is thought to have been introduced into the Castle Loch of Lochmaben in the early monkish times, when it was essential, for the proper observance of church fasts, to have an ample supply of fish for fast-day fare. It is curious as regards the vendace that they float about in shoals, that they make the same kind of poppling noise as the herring, and that they cannot be easily taken by any kind of bait. At certain seasons of the year the people assemble for the purpose of holding a vendace feast, at which times large quantities of the fish are caught by means of a sweep net. The fish is said to have been found in other waters besides those of Lochmaben, but I have never been able to see a specimen anywhere else. There are a great number of traditions afloat about the vendace, and a story of its having been introduced to the lake by Mary Queen of Scots. The country people are very proud of their fish, and take a pride in showing it to strangers. The principal information I can give about the vendace, without becoming technical, is, that it is a beautiful and very symmetrical fish, about seven or eight inches long, not at all unlike a herring, only not so brilliant in the colour; and that the females of the vendace seem to be about a third more numerous than the males—a characteristic which is also observed in the salmon family. The vendace spawn about the beginning of winter, and for this purpose gather, like the herring, into shoals. They are very productive, and do not take long to grow to maturity.
The peculiarities of the Lochleven trout may be chiefly ascribed to a peculiar feeding-ground. Having lived at one time on the banks of this far-famed loch, I had ample time and many opportunities of studying the habits and anatomy, as well as the fine flavour, of this beautiful fish, which, in my humble opinion, has no equal in any other waters. Feeding I believe to be everything, whether the subjects operated upon be cattle, capons, or carps. The land-locked bays of Scotland afford richer flavoured fish than the wider expanses of water, where the finny tribe, it may be, are much more numerous, but have not the same quantity or variety of food, and, as a consequence, the fish obtained in such places are comparatively poor both in size and flavour. Nothing can be more certain than that a given expanse of water will feed only a certain number of fish; if there be more than the feeding-ground will support they will be small in size, and if the fish again be very large it may be taken for granted that the water could easily support a few more. It is well known, for instance, that the superiority of the herrings caught in the inland sea-lochs of Scotland is owing to the fish finding there a better feeding-ground than in the large and exposed open bays. Look, for instance, at Lochfyne: the land runs down to the water’s edge, and the surface water or drainage carries with it rich food to fatten the loch, and put flesh on the herring; and what fish is finer, I would ask, than a Lochfyne herring? Again, in the bay of Wick, which is the scene of the largest herring fishery in the world, the fish have no land food, being shut out from such a luxury by a vast sea wall of everlasting rock; and the consequence is, that the Wick herrings are not nearly so rich in flavour as those taken in the sea-lochs of the west of Scotland. In the same way I account for the rich flavour and beautiful colour of the trout of Lochleven. This fish has been acclimatised with more or less success in other waters, but when transplanted it deteriorates in flavour, and gradually loses its beautiful colour—another proof that much depends on the feeding-ground; indeed, the fact of the trout having deteriorated in quality as a consequence of the abridgment of their feeding-range, is on this point quite conclusive. I feel certain, however, that there must be more than one kind of these Lochleven trouts; there is, at any rate, one curious fact in their life worth noting, and that is, that they are often in prime condition for table use when other trouts are spawning.
The powan, another of the mysterious fish of Scotland, is also considered to be a fresh-water herring, and thought to be confined exclusively to Lochlomond, where they are taken in great quantities. It is supposed by persons versed in the subject that it is possible to acclimatise sea fish in fresh water, and that the vendace and powan, changed by the circumstances in which they have been placed, are, or were, undoubtedly herrings. The fish in Lochlomond also gather into shoals, and on looking at a few of them one is irresistibly forced to the conclusion, that in size and shape they are remarkably like the common herring. The powan of Lochlomond and the pollan of Lough Neagh are not the same fish, but both belong to the Coregoni: the powan is long and slender, while the pollan is an altogether stouter fish, although well shaped and beautifully proportioned.
I could analyse the natural history of many other fish, but the result in all cases is nearly the same, and ends in a repeated expression that what we require as regards all fish is the date of their period of reproduction; all other information without this great fact is comparatively unimportant. It is difficult, however, to obtain any reliable information on the natural history of fish either by way of inquiry or by means of experiments. Naturalists cannot live in the water, and those who live on it, and have opportunities for observation, have not the necessary ability to record, or at any rate to generalise what they see. No two fishermen, for instance, will agree on any one point regarding the animals of the deep. I have examined every intelligent fisherman I have met within the last ten years, numbering above one hundred, and few of them have any real knowledge regarding the habits of the fish which it is their business to capture. As an instance of fishermen’s knowledge, one of that body recently repeated to me the old story of the migration of the herring, holding that the herring comes from Iceland to spawn, and that the sprat goes to the same icy region in order that it may fulfil the same instinct.
“Where are the haddocks?” I once asked a Newhaven fisherman. “They are about all eaten up, sir,” was his very innocent reply; and I believe this to be true. The shore races of that fish have long disappeared, and our fishermen have now to seek this most palatable inhabitant of the sea afar off in the deep waters. Vast numbers of the haddock used to be taken in the Firth of Forth, but during late years they have become very scarce, and the boats now require to go a night’s voyage to seek for them. If we knew the minutiæ of the life of this fish, we should be better able to regulate the season for its capture, and the percentage that we might with safety take from the water without deteriorating the breeding power of the animal. There are some touches of romance even about the haddock, but I need not further allude to these in this division of my book, as I shall have to refer to it again under the head of the “White Fish Fisheries.” It is, like all fish, wonderfully prolific, and is looked upon by the fishermen as being also a migratory fish, as are also the turbot and many other sea animals.
The family to which the haddock belongs embraces many of our best food fish, as whiting, cod, ling, etc.; but of the growth and habits of the members of this family we are as ignorant as we are of the natural history of the whitebait or sprat. I have the authority of a rather learned Buckie fisherman (recently drowned, poor fellow! in the great storm on the Moray Frith) for stating that codfish do not grow at a greater rate than from eight to twelve ounces per annum. This fisherman had seen a cod that had got enclosed by some accident in a large rock pool, and so had obtained for a few weeks the advantage of studying its powers of digestion, which he found to be particularly slow, although there was abundant food. The haddock, which is a far more active fish, my informant considered to grow at a more rapid rate. On asking this man about the food of fishes, he said he was of opinion that they preyed extensively upon each other, but that, so far as his opportunities of observation went, they did not as a matter of course live upon each other’s spawn; in other words, he did not think that the enormous quantities of roe and milt given to fish were provided, as has been supposed by one or two writers on the subject, for any other purpose than the keeping up of the species. The spawn of all kinds of fish is extensively wasted by other means; and these animals have no doubt a thousand ways of obtaining food that are yet unknown to man; indeed, the very element in which they live is in a sense a great mass of living matter, and it doubtless affords by means of minute animals a wonderful source of supply. Fish, too, are less dainty in their food than is generally supposed, and some kinds eat garbage of the most revolting description with great avidity.
I take this opportunity of correcting the very common error that all fish are migratory. Some fishermen, and naturalists as well, picture the haddock and the herring as being afflicted with perpetual motion—as being wanderers from sea to sea and shore to shore. The migratory instinct in fish is, in my opinion, very limited. They do move about a little, without doubt, but not further than from their feeding-ground to their spawning-ground—from deep to shallow water. Some plan of taking fish other than the present must speedily be devised; for now we only capture them—and I take the herring as an example—over their spawning-ground, when, according to all good authority, they must be in their worst possible condition, their whole flesh-forming or fattening power having been bestowed on the formation of the milt and roe. I repudiate altogether this iteration of the periodical wandering instincts of the finny tribes. There are great fish colonies in the sea, in the same way as there are great seats of population on land, and these fish colonies are stationary, having, comparatively speaking, but a limited range of water in which to live and die. Adventurous individuals of the fish world occasionally roam far away from home, and speedily find themselves in a warmer or colder climate, as the case may be; but, speaking generally, as the salmon returns to its own waters, so do sea fish keep to their own colony.
Our larger shoals of fish, which form money-yielding industries, are of wonderful extent, and must have been gathering and increasing for ages, having a population multiplied almost beyond belief. Century after century must have passed away as these colonies grew in size, and were subjected to all kinds of influences, evil or good: at times decimated by enemies, or perhaps attacked by mysterious diseases, that killed the fish in tens of thousands. At Rockall, for instance, there was lately discovered a cod depôt, about which a kind of sensation was made—perhaps by interested parties—in the public prints, but the supply obtained at that place was only of brief duration. This fish colony, which had evidently fixed upon a good food-giving centre, was too infantile to be able to stand the heavy draughts that were all at once made upon it. Schools or shoals of fish, when they are of such an extent as will admit of constant fishing, must have been forming during long periods of time; for we know that, despite the wonderful fecundity of all kinds of sea fish, the expenditure of both seed and life is something tremendous. We may rest assured that, if a female codfish yields its roe by millions, a balancing-power exists in the water that prevents the bulk of them from coming to life, or at any rate from reaching maturity. If it were not so, how came it, in the days when there was no fish commerce, and when man only killed the denizens of the sea for the supply of his individual wants, that our waters were not, so to speak, impassable from a superfluity of fish? Buffon has said that if a pair of herrings were left to breed and multiply undisturbed for a period of twenty years, they would yield a fish bulk equal to the whole of the globe in which we live!
The subject of fish growth—particularly as regards the changes undergone by the salmon family—will be found further elucidated under the head of “Fish Culture,” and incidentally in some other divisions of this work.