The Grey Loach is thought to have bred considerably.
The Atherine continues to breed.
I formerly mentioned that the flavour of the several fishes was improved: this is now more positively asserted, in addition, of the Basse, the Plaice, and the Red Loach. Others were mentioned in former communications.
Loss of property, or flavour, has been made a speculative objection by the unvarying objectors. General experience has shown, that in all fishes, as far as known, the access to fresh water, or fresh water food, improved the flavour; in many, in oysters, muscles, cockles, shrimps, it is vulgarly notorious; as in mere sea water they are worthless.
There is a popular objection, on this head, made by the country gentlemen, which I must answer; to those who think about what they know, it would have been superfluous. The salmon is good when it comes from the sea, and bad when it is returning. Doubtless, it is; while the reason ought to be plain, even to an angler. It is in full health in the first case: in the latter, it has spawned; and, at that period, every fish is proportionally as bad as the salmon; many are a great deal worse. The fault is not in the water, nor probably in the food; it is in the spawning, and with any food the same effect takes place, in all fishes, everywhere.
I suggested in former communications, that an essential point [p325] to ascertain, in any view of economy, or management, would be the proper balance of species; to discover what kinds would so live together that all the species might find food; might breed, each to its useful limits, so as to be serviceable to ourselves, the keepers or the flocks, and without hazard of the extermination of any kind. I may illustrate what is here meant, by a simple fact, in the ordinary economy of fresh water fishes in confinement. Pike and perch can live together, because the natural defences of the perch prevent the pike from exterminating the race, voracious as the enemy is. If trout and pike were confined in a narrow water, the trout would be destroyed.
Or otherwise, it must be our object to ascertain, in an economical view, how to feed, by means of species that we do not desire to eat, those which we do cultivate for our own uses. This is a difficult question, which can only be overcome by time and experience; by knowledge; by knowledge, when we are in a state of entire ignorance; ignorance of every thing that relates to fishes, as great as if they were the inhabitants of another planet. This was one great source of difficulties with us in this case; and I, myself, must plead guilty, I fear, to a general recommendation of introducing every fish as a mere matter of trial; the result of which has been mischievous. The basse appears to have been the great enemy; to have eaten up the greater number of many species, and given no return. It has proved the pike of this pond. This could not have been foreseen; it is a caution for future speculators. Others will be discovered in the course of trial. It appears also that the common crab has proved destructive, probably by eating the spawn of larger fishes. From some enemy or other, the eels, which at first abounded to an incredible degree, have most materially diminished, and so have the shrimps. The latter, at least, appear to have been destroyed by the basse. Time and trial will teach us what to do in this case; in the infancy of ignorance, man might have supposed that he could keep wolves and sheep in one field, and have constructed a pen for foxes and fowls, rabbits and weasels. We must not accuse nature of our own ignorance.
The question is here a difficult one; but a little more study [p326] of the general habits of fishes, merely as we know them already, and even of their anatomy, will go far to lay the foundation of useful rules on this head, even without a hazardous trial, which may ultimately not become in our power to remedy, as I much fear may prove the case with respect to these unlucky basse. Not to enter on this further than as it may serve for a general illustration of what is here meant, the anatomy of the mullet proves that it lives on worms; on the lumbricus marinus, and others; and so do its habits. So also may the very food of others, as found in the stomach, serve to indicate their natural or ordinary food. Reversely, the anatomy of a cod’s jaws, and its stomach also, prove it to be omnivorous, omnivoracious. Or, further, the anatomical character of the diodon proves that it eats shell-fish; as we are equally able to limit the range of food in the flat-fish which have no air-bladders, and cannot quit the ground.
But in this brief communication, I must not enter further into this subject than is necessary for mere illustration. I may take some further opportunity to point out the probabilities, as to mutual food and protection, in any artificial cultivation of this nature, as they might be derived from studying the little that we do know about the structure and habits of fishes. All that I need add here, is, that I have suggested the introduction of limpets, periwinkles, and cockles; as affording food without furnishing enemies: a matter which had been overlooked. To exterminate the enemies which have been unwarily introduced, will not prove so easy a task; unless, at least, we could find their natural enemies; find the great secret by which alone, in all cases, man can make war on those whom neither his artillery, his physic, nor his politics can reach.
The transportation of fishes has been objected to as difficult. I had occasion to make some remarks on this formerly, and on the vitality of some kinds. The difficulty is not so great as has been imagined. The fact generally is, that fishermen, even down to the very sentimentalists who worship the gentle Izaak, and who are sometimes scarcely possessed of the wit of a fish, treat them as they would a stone; as if they had not lives, and wills, and opinions, and were not part of the same [p327] creation as ourselves; as if that creation, which outnumbers ourselves by millions of millions almost beyond algebra to express, was not, like ourselves, under His care. They are easily killed by violence; they kill themselves by over-exertion, from anatomical peculiarities; as every trout-fisher knows; that is to say, the fact, not the cause. Let them be treated with gentleness when taken, as if they could feel; and they will not die in being removed into a cask of water. The flat fish are all peculiarly tenacious of life, so are all those of firm muscles generally: the vitality of the carp and of the minnow also is notorious; and so it is as to many other kinds. All these can be removed, and carried far, even in straw; but in truth, he who chooses to make his experiments like a philosopher, and who desires to succeed, will not fail.