CHAPTER VIII
GENERAL MANAGEMENT.
Feeding should be performed twice or thrice a week, and will be as amusing to the observer as gratifying to the fishes. Bread is not so objectionable as many have stated. Carp, bleak, and minnows eat it greedily, and soon grow tame if regularly fed with it. Most small fishes take insects, such as flies, spiders, ants, and soft larva, greedily; but the large fish disdain such diet. Small red worms, and white of egg, are good general foods, and seem highly beneficial. When feeding, see that the carp get enough, for they are slow fish, and get robbed wholesale by their more lively neighbours. Food not eaten will decay, unless speedily removed, hence care must be exercised on this head.
Confervæ.—When the tank has been established a few weeks, the inner sides of the glass will show signs of a green tinge, of a slimy nature. This is owing to the growth upon it of minute forms of vegetation. If this is allowed to go on unchecked, the glass will in time become opaque, and the view of the interior will be lost. Hence it must either be kept down in growth or occasionally removed.
Uses of Mollusks.—It is to prevent this rapid growth that water-snails are registered among the tenants of right, for these creatures subsist on vegetable matter only, and if a goodly number be thrown in, they will be found perpetually at work, eating the green growth from the sides, and thus constantly preserving an open prospect.
Objections to Mollusks.—In a highly ornamental tank, water-snails may be thought objectionable, as interfering somewhat with the beauty of the scene. I know the ardent naturalist will cry out against this remark, and ask me if I can find a prettier object than a Planorbis corneus, coiled round like a horn of plenty; or a full-grown Paludina with its globular hybernaculum richly bronzed and mottled. I tell my friend that I love the pretty creatures as much as he does, yet, as I write for everybody who wishes to keep an aquarium, I feel bound to consider how it is to be managed without them, if their absence is desired. I confess too, that I do object to their appearance in some cases myself, as I do also to beetles, and all other insects in a tank fitted up for the adornment of a drawing-room, however necessary they may be in the tank of a student.
In the first place, Paludinæ and Planorbis are the only kinds to be trusted in a general collection of plants, and the last is most trustworthy of any. Lymnea are all fond of substantial dishes, and eat as much vallisneria as they do of the mucuous growth. A dozen of these gentry will most effectually check the vegetation of the tank, by eating holes in the handsomest leaves of the Stratoides, and biting into the very heart of the Vallisneria. Starwort, too, they are very fond of, and soon clear the bottom of every fragment. Yet, the Lymnea are admirable cleaners, the pity is, that they will not see what is required of them, and do that only.
Again, the univalve mollusks do not keep the sides so clean, but that an occasional cleansing of another kind is sometimes necessary, and if the aquarian is not disposed to keep an army of quite semi-efficient scavengers, the remedy will be found in an occasional cleansing of the sides, by means of a sponge attached to a stick, which must be plied over the whole surface, and occasionally taken out and washed in clean water, to remove the green scum, that it soon gets covered with.
Use of Confervoid Growths.—But I should object to any frenzy about cleansing tanks. As I said at starting, they should be self-supporting, and if Planorbis or Paludinæ are used in the proportion of about four of each to every gallon of water, a good view will always be preserved with the use, now and then, of the sponge alone.
Periodical Cleansing.—When a tank has stood twelve-months or more, the water not having been changed at all during the whole time, it may be necessary to turn out the contents and re-stock it. This is not to be done unless the bottom has become black, and the roots of the plants show signs of decay, in fact, not unless it really wants it, and if bottomed with mould it certainly will, and it must be done accordingly. The live stock should be removed by means of a hand-net, the water drawn off by means of a syphon of glass, or gutta percha, and the plants taken out carefully and put by themselves, and then after removing the bottom the glass can be quickly cleaned with the aid of water and fine sand, or rotten-stone.
Exhaustion of Oxygen is made manifest by the fishes coming to the surface to gulp air, and it is also manifested by their retiring to the bottom, and quietly extending themselves on their backs in “horizontal repose”—the repose of death. If too many animals be crowded into the vessel, this will soon happen, and either the number must be reduced or the water must be frequently changed, or we must have recourse to aeration. I consider the two latter remedies a proof of the incompetency of the aquarian—the necessity marks very bad management indeed.
Temperature.—If the aquarium be too much exposed to the heat of the sun in summer, or to the heat of a fierce fire in winter, the water will get tepid, and signals of distress will be shown by the protrusion of many panting mouths at the surface. I find that if the temperature rises above sixty degrees, things do not go on so well. The use of a blind or paper screen is, therefore, essential in summer time.
On winter evenings, when the room is made cozy by blazing blocks of coal, the collection will often show signs of distress. By opening the lower window-sash one or two inches when leaving the room for the night, things may be restored to a normal state in a few hours, and even if the weather is somewhat severe no harm will be done. At the same time intense cold checks the growth of the plants, and throws the fishes into a state of torpor, and the freezing of the water may cause the bursting of the tank.
In summer time, if the tank should get accidentally heated, it may be quickly cooled by wrapping around it a coarse cloth saturated in water, and keeping it wet from time to time. These matters may be much simplified by fixing a small thermometer within the tank below the level of the water.
Dead specimens must be removed as quickly as possible. Bivalves are generally very hardy, but if death happens to one, the production of sulphuretted hydrogen is very rapid, and quickly fouls the tank.
Disease of Fishes.—I have tried numerous remedies for the diseases which beset fishes in winter, but with very little success. When the caudal fin gets coated with a fungoid growth, I have at once cut it off by means of a pair of scissors, and it has usually grown again in a few weeks. I have a couple of minnows now, that were so operated on last winter, they are as hearty as ever, and their tails are quite renewed. Diseased animals should always be removed to a pan of fresh river water, and placed in a quiet cool place, where they will probably recover.
