Corals, even tropical kinds, live comfortably in the balanced aquarium for years. A cold water species is to be had in Long Island Sound and on the Jersey coast about Long Branch.
Oysters, mussels and clams live comfortably in the sand and gravel. Sea anemones "blossom," attached to stones and shells; they are among the greatest attractions of the aqua rium.
The Tube Worm (Cistenides), in its sandy horn, and Serpula, in its twisted limy tube, do well. The Ship Worm (Teredo), in a fragment of honeycombed wood, thrives in the company above described.
Botryllus is a coloured, gelatinous mass, with a 14 The Balanced Aquarium and the Snailery arrangement of the individual zooids, which looks somewhat like coral. It is found attached to eel-grass and to wharf piles.
Sea Squirts are globular, gelatinous creatures that send out a jet of water when disturbed. They will live and multiply in the aquarium.
Snails of the periwinkle group (Littorina) are scavengers. They eat decayed vegetable matter, and pick up the crumbs dropped by fishes. The Dog Whelk (Nassa trivittata) helps at this job of cleaning, and he is an ornament to the tank. But he may drill a hole in the shell, and suck the life blood of your favourite bivalve, reminding you that he prefers fresh to stale food. Be ware the Whelk (Buccinum), the Moon Shell (N atica), and the Drill (Urosalpinx), for they will slay without mercy every bivalve you put within their reach.
Hydroids, microscopic creatures of exceeding beauty of form, often mistaken for delicate seaweeds, occur in the aquarium as if spontaneously, attached to the glass sides or to objects inside.
Hermit and horse-shoe crabs, prawns and little blue crabs should be kept in separate jars. They are most interesting and beautiful. But they are too hungry and too selfish to share the quarters of better-mannered creatures.
Do not attempt to put into one jar at one time any such number and variety of plants and animals as I have described. Understock, rather than overstock, the aquarium.
Put in fresh water, as evaporation lowers the level.
Feeding the Animals.—Mince a fresh clam or oyster and feed the sea anemones and corals, by holding a bit on the end of a sharp stick in front of the disk, where the tentacles can reach it. They take it eagerly. The juice lost to the water will feed the bivalves. Cease to offer it, when food is no longer taken. Feed regularly. Bits of meat or clam are good food for the car nivors, which cannot be trusted in the general aquarium.
Cleaning the Aquarium. — Dust may be removed from the surface of the water by skimming with pieces of clean white blotting paper. If dead leaves foul the water, put in more water snails, found among decayed leaves on the edges of ponds and ditches. Slime-covered corners of the same pond furnish you the kind of snail which will clean the scum off the sides and sur face of your' tank quickly. There are marine snails that will do the same work in the salt water aquarium. When such means
15 The Balanced Aquarium and the Snailery fail, a swab of flannel, wrapped close on a small block, curved to fit the sides of the jar, and affixed to a handle of convenient length, is the best cleaning tool. Wash the dirt out of the flannel after drawing it once up the glass side.
A half-inch glass tube is used to take up bits of food from the bottom of the tank. With the thumb over one end, place the other close to the refuse. Lift the thumb slightly, and the object will rise in the tube. Close the top again with the thumb while taking the tube out of the water. Never leave bits of food on the bottom of the tank. If you prefer, put a hungry crayfish or crab in to clear up the garbage. But don't forget to take him out when his scavenger work is done. He is a dangerous visitor to leave there long.
Plants must be removed when they show symptoms of old age. Animals, too, must be watched, and removed when they are unhealthy. Sick animals often hide under the rocks to die. Hunt them out before they foul the water.
Sometimes turbid water may be cleared by dipper aeration. Dipping the water, and pouring it slowly back, with the dipper held six or eight inches above the surface, mixes fresh air with the water, and thus "makes it alive." This should be done carefully so as not to dislodge the plants, nor otherwise disturb the arrangements. Do not empty the tank until all expedients have failed.
Use a siphon to draw off the water, if it has become stagnant. Carefully wash the jar, the gravel, and other contents that are to be replaced. Install plants and animals in clean fresh water. Try to avoid the necessity of another such housecleaning.
Tools Needed for the Aquarium. — Handling fish and other creatures is often the cause of their death. Moreover, it is not pleasant to roll up a sleeve and dive to the elbow into an aquarium. The tools needed are few and simple. Supply these, and so avoid damage and discomfort.
1. A small dip net on a long handle, useful for the transfer of any animal from one tank to another.
2. A pair of wooden forceps longenough to reach objects on the bottom of the jar, useful in rearranging rocks,anchoring plants, etc.
3. A glass tube for taking up refuse.
4. A long, pointed stick for feeding corals, etc.
5. A long-handled swab for cleaning the inside of the jar. 16 The Balanced Aquarium and the Snailery 6. A siphon, or merely a piece of soft rubber tubing, to draw off the water in emptying tank.
Much elaborate and unnecessary equipment is offered by dealers in aquarium supplies. The essentials are named above. Most of these articles can be made at home; the others may often be bought at a drug store.
Wholesale houses carrying druggist's supplies usually can furnish such jars as are required. There are several firms in New York City.