The sweet-scented Rush, members of the Alisma tribe, the noble Sagittaria of six species, the Hornwort (Ceratophyllum) of two species, and for more delicate purposes, Chara and Nitella may be recommended as suitable additions to the botanical department of the Aquarium.
FISHES FOR THE AQUARIUM.
I shall here give the names and a few particulars of the history of the fishes that are most suitable for the aquarium, reserving my notes on the grouping and general stocking for a subsequent chapter. It is to the interesting family of Cyprinidæ we are to look for our chief supplies. This tribe of fishes belongs to the great division of Malacopterygii, or those having their fin-membranes supported by flexible rays, which are either pointed or branched, or both.
Cyprinus carpio, the British carp, is a handsome fish, differing slightly in structure from the Prussian and gold carp; yet, in general outline, preserving the true carp type—plumpness of body, iridescence of colour, and ease of movement in the water. This carp has a moderately-developed pair of moustachios, in the form of a barbule, at the upper part of each corner of the mouth, and a second one above it, on each side. Like the rest of its kindred, it is very tenacious of life, and does not quickly suffer from exhaustion of oxygen. It is an old fish, so to speak, for it was a favourite with the ancients. Pliny and Aristotle both speak of it in high terms of praise, and record that it lives to a hundred years of age, becoming, in that time, as white and hoary as an "ancient mariner" should. It is not indigenous to our rivers, though, as far back as 1496, mention is made of it in the "Boke of St. Albans," quoted by Mr. Yarrell. It has been known to attain to a weight of twenty pounds, and in Holland is frequently kept alive in wet moss, and fattened on boiled potatoes. In this way it is said to live three weeks.
GUDGEON, PRUSSIAN CARP, LOACH, & BREAM.
C. gibelio is the noble Prussian carp, unquestionably the best of all fishes for aquarian purposes. It will survive the wreck of a whole establishment, even if the water gets putrid and almost exhausted of oxygen. The easy, graceful motions, the beauty of the colouring, and the docility, of this fish, must make it a favourite and a pet wherever it is kept. I have always had a large number of them, some of considerable size; they group themselves like friends on good terms of acquaintance, take an interest in whatever goes on in the room where the tank stands, and elegantly poised in mid-water, will watch their proprietor for hours. Small, red earth-worms, young water snails, and home-made bread, are the best of foods for them. They will seldom eat bread at first, but soon get to like it, eat it greedily, "and ask for more." The Prussian carp may be taught to feed from the hand, even more boldly than the minnow, and readily assemble themselves for inspection when the side of the glass is gently tapped with the finger-nail. None of the carp family are carnivorous in any great degree. Mr. Yarrell says the Prussian carp will recover after having been thirty hours removed from water.
C. carassius.—The crucian, or German carp, is easily distinguished from its compeers by its bream-shaped back, which rises from the nape into a high arch along the line of the dorsal fin. It is to be found in the Thames, between Hammersmith and Windsor, whether for the angler to kill or the aquarian to preserve. It is less hardy than the Prussian carp, and a little subject to fungoid growths.