The Book of the Aquarium/Part 2/Chapter 7

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I shall in this Chapter only notice such particulars in the management of aquaria as belong especially to the marine department, since some of the directions given in the former division of the work apply to tanks of all kinds, and need not be repeated. When preliminary difficulties have been surmounted, the matter of first importance is the selection of the stock, and its arrangement in accordance with just principles.

Grouping.—In Chapters IV. and V. I have enumerated the kinds of animals and plants most suitable for aquaria, and must now caution the beginner against the injudicious grouping together of creatures of dissimilar habits. Anemones may, as a rule, be kept together. The several species agree well, and seldom or rarely injure each other; but star-fishes and crabs are best kept in vessels apart from them. Star-fishes are very destructive, and readily absorb the bodies of mollusks out of their shells. If exception is to be taken to any particular anemone, I think the grand plumosa must suffer by it; for this noble creature gives off a flocculent exudation, which seems injurious to other kinds. I have generally kept the plumose anemone in company with A. mesembryanthemum, A. bellis, troglodytes, and others, without perceiving any bad result; but I have always been careful to remove the slimy exuvia daily, by means of the dipping tube. Respecting mollusks, and especially trochus and most bivalves, it should be borne in mind that they are apt to die off rapidly, and to cause a putrescence of a most obnoxious character, which soon spoils the water, and causes a general havoc. Another remark applicable to mollusks is this, that the Eolids—members of the Nudibranch, or naked mollusks—are destructive of anemones, and delight in nibbling holes in their coats, or eating off their tentacles; whereas the pretty doris may be kept as long as it will live, in company with the most delicate creatures, without offering offence to any. The more varied the collection the more is our interest in its examination increased; and the possessor of a single vessel, or of a tank, and a few auxiliary jars, will be naturally anxious to preserve representatives of as many tribes as possible; and this may be done, to a certain extent, by appropriating the vessels to such creatures as agree amicably in confinement. It is, indeed, possible, if a vigilant watchfulness be observed, to bring together and preserve, for a length of time, specimens of creatures that are naturally antagonistic to each other; but where Crustaceans can be kept apart in one vessel, with, perhaps a few fish, such as gobies and blennies—a second appropriated to anemones and madrepores—and a third to mollusks, madrepores, and tubeworms—there will be the greater certainty of success, and less supervision will be required. Crabs are very annoying to anemones, as they scratch and sprawl over the delicate creatures; and shrimps, prawns, and fishes frequently fall a prey to the barbed threads and the tentacles of the anemones; the latter also frequently take possession of the mouths of the cells of tube worms, and of the openings of the shells of mollusks, and thus suffocate the inmates, and insure their own death by the putrescence that ensues upon the demise of their victims.

Sulphuretted hydrogen.—When the death of an animal occurs, the water soon gets putrid; the stones assume a rich brown tint, the sides of the vessel lose their brightness, and an effete odour indicates the cause of the disturbance.

Preservation of the Water.—To those who live near the sea it is an easy matter to change the water, as soon as it shows signs of disorganization, but since the majority of those who will consult this work will have to depend on Mr. Bolton’s marine salts, it is necessary that I should suggest in what way, and in the best manner, the water may be preserved, not only to avoid the expense, but the trouble attending a new supply. Charcoal is the grand restorative, purifier, and preserver; and for this department of aquarium management may be regarded as the ne plus ultra.

In the second Chapter of this part of the work I have described the process necessary in preparing artificial water by means of the filter. Now, whatever happens, set the filter to work, it will revive exhausted stock by aeration, destroy sulphuretted hydrogen by the contact of the water with the charcoal, and remove all fragments of decayed weed, flocculent threads given off by anemones, and restore the whole to strength and purity. I repeat what I have already said more than once, that the necessity for changing the water is a proof of injudicious management; every new supply is a witness of the aquarian’s lack of skill, as Mr. Lloyd wisely says, “properly managed, the water and other contents of an Aquarium may be kept unchanged for periods indefinitely prolonged.” For the sake of aquarian science, I do implore the student to surmount any and every difficulty, rather than own the weakness implied by changing the water.

Aeration is frequently referred to in works on the Aquarium. It is at variance with the self-sustaining theory, and there is something wrong where it is wanted. If the tank is stocked before the plants are well established, or if overstocked with a crowd of animal life, or if sulphuretted hydrogen be produced and make its presence manifest to the nose, then aeration may be necessary. A cup or jug may be used to dip water from the surface, and pour it back again from a height in a thin stream. Or a filter may be placed over the tank and filled from the surface, and the water allowed to drip back. But the most efficient instrument is a common syringe. This is simply to be charged at the surface, and discharged again with some force, so as to send a stream of oxygenised water deep into the tank. The process should be repeated for a quarter of an hour at least.

Filter.—A bee glass or a common flower-pot may soon be made into a filter. Thrust a piece of sponge into the hole in the bottom, and upon it lay a stratum of washed sand and powdered charcoal. Pass the water through it, and it will be purified, and saturated with oxygen at one and the same time. With the river-tank, the simplest way of reviving exhausted stock is wholly or partially to change the water; with marine stock, such a change is not easy, and the filter comes more legitimately into use. As already remarked, the necessity for aeration marks error in management, except when you have stock for which no proper receptacle is at hand, or any such special contingency.

Decay of Plants.—The sea-weeds are apt to acquire a pale tint, which is the first evidence of decay. This generally happens with the first marine stock, when Ulva and Enteromorpha are used to season artificial water. When the water gets ripe, the plants recover and make healthy growth, but if many white fronds appear, lift out the blocks on which the plants are fixed, trim away the decayed portions with a pair of scissors, and then scrub the stones with a small brush in a little waste sea-water, and replace them; they will soon recover. If red plants have been hurriedly introduced, and decay manifests itself, remove them at once, and waste no time in attempts at revival. Mr. Lloyd will supply a new stock for a trifle, and it is better to begin de novo than to attempt to cure the incurable.

Death of Anemones.—If you observe any of the anemones to shrink up like button-covers, lift them out into a shallow vessel, and aerate them liberally. When small beads of gas appear upon them, you may rest assured that they have gone beyond the—

“ Bourne from whence no traveller returns;”

for the first outward proof of death is the formation of bubbles of sulphuretted hydrogen upon their bodies, and they should be removed before this spreads and devastates the tank.

Removal of Objects.—For the removal of portions of decayed weed, and other small noxious bodies, from the bottom, a glass tube of ¼ or ½ inch diameter, open at

both ends, will be found very useful. Place a thumb or finger on the top of the tube, and thrust it down over the object to be removed, then remove the finger, and the matter will rise in it. Lift the tube up to the surface of the water, then place the finger on again, and lift the whole away. The advantage of this plan is, that no disturbance is occasioned. A pewter spoon bent to a right angle, and attached to a stick is very useful for lifting up objects that are too large for the dipping tube.

Density of the Water.—Evaporation causes the pure water to escape from the Aquarium, and hence there is a constant tendency to increase of density—in fact, if left alone, the water in the tank soon gets too salt. To prevent this, additions of pure spring or distilled water must be made from time to time, and the amount regulated by a specific gravity bubble, which it would be as well to leave at all times floating in the tank. This instrument registers the density much more accurately than the hydrometer, for it is more delicate in its determination of a balance. I find it expedient to use two bubbles of different specific gravities—one which just floats when the water is sufficiently fluid, and another which just sinks when it is sufficiently saline. The movement of either indicates at once the exact cause, and enables the aquarian to regulate the density to perfection.

Green Stain.—I have never been troubled with confervoid growths in tanks filled with artificial water, though the same water has been in use during periods of from a few months to two years. When it occurs, the mollusks are the natural remedy, the sponge the artificial one. But a strange affection—which I think is most common in spring—is the sudden occurrence of a green turbidity, which destroys the translucence, and for which neither sponge nor winkle can afford a remedy. It is not a growth on the side of the vessel, but a green stain pervading the water, as if a green colouring matter had been dissolved in it. Mr. Gosse says, “ it is vegetable in its origin, and arises from an infinite number of the spores (or seeds) of green Algæ dispersed through the fluid, and held in suspension there.” Mr. Gosse further says, “ I know of no cure for this,” but he quotes Mr. Lloyd’s experience as demonstrative of its curability by placing the water “ in a dark closet for two or three weeks.”

From the experience I have had in this matter, I have no hesitation in saving that the filter will be found an instantaneous remedy; the water need not be drawn off at all, but kept filtering through charcoal by frequent filling of the filter from the surface. In May last, a tank of mine became suddenly opaque, though otherwise in excellent order. The collection was valuable, and a disturbance of it would have been attended with risk. I suspended an old flower-pot half filled with fresh charcoal and sea-side grit above it, and set the filter to work. As fast as the filter ran out, I filled it again from the tank, without disturbing anything, and a change for the better was perceptible in an hour. Two days after, the water was as bright as ever, and the stock in the finest possible condition, owing to the brisk æration they had gained by the experiment.

Feeding.—Anemones generally do not require feeding, though the Daisy and the Dianthus will greedily partake of small fragments of oyster and minced mutton, and some other kinds will occasionally eat of the same food; but I cannot recommend the beginner to feed Anemones, for, in a well managed tank, Infusoria are sufficiently abundant to provide them with all they require, and food not eaten soon decays, unless speedily removed. Crabs and prawns positively require feeding, and Madrepores may be fed for amusement. Small fragments of the lean of raw meat should be given, or the flesh of a cooked prawn, and twenty-four hours afterwards, the undigested morsels should be removed.

The Syphon is a simple affair enough. In using it, place the short end below the surface of the water in the

tank, and apply the mouth to the longer end, and draw till the water flows; it will then continue to flow as long as the short end is kept under water. If you object to promote aquarian science by means of suction, first fill the syphon with water, and apply a finger to each end, and so turn it over, and withdraw the fingers when the short end is dipped beneath the surface of the water in the tank. Mr. Lloyd sells a syphon expressly for the purpose, which the aquarian should possess.

Purchase of Specimens.—There are now many dealers in Aquarian stock, but very few of them supply marine stock in any variety. I have my readers’ interest only at heart when I suggest, that no one should attempt to set up an Aquarium without first paying a visit to the establishment of Mr. W. Alford Lloyd, of No. 20, Portland Road, Regent’s Park, where choice may be made from a stock consisting of thousands of specimens, supplied, as, the oyster shops say, “fresh every day.” Mr. Lloyd was a labourer in the field years before the Aquarium became popular, and his experience, attained by patient study, is now at the service of all who need advice or assistance in any department of the subject.

I have no interest in this matter beyond doing justice to my reader, and beg to add that Mr. Hall, of City Road, has supplied me with marine stock of high character, and that I can recommend him as an honest and intelligent naturalist, though, on marine matters he will not attempt to compete with Mr. Lloyd, for the latter has now the name, the trade, and the organization, and since he keeps everything, so he can supply everything of the commonest or rarest kind, in the highest condition.