C. phoxinus, the minnow. An aquarium without minnows is no aquarium at all—it is a makeshift. With a shoal of minnows and a few Prussian Carp an aquarium may be considered fairly stocked, because there is really something to look at, something to amuse, and something to instruct. The minnow is a bold and impudent fish; he is at his ease in less than an hour, and in a week will show a sign of attachment and familiarity. They do not live beyond three years, but will reach that age in the confinement of a tank. Like carp and tench (and asses), minnows may be said never to die, for they survive the severest trials of heat and cold, neglect and bad treatment. The colours are pleasing, and bear some close resemblance to the mackerel; but fright will make them assume a pale fawn colour in an instant. Disease seldom attacks them, and when it does, they speedily recover if thrown into a large pan under a jet of water. Minnows spawn in June, and just before that time acquire their gayest mottlings of green, and bronze, and silver, losing colour considerably after spawning.
C. gobio.—The gudgeon is an every-day sort of fish, proper enough in a general collection, but where room is scarce it may very well be spared. In its markings the gudgeon has a striking appearance. It is a hardy fish, and rarely shows signs of exhaustion.
C. Tinca.—The tench is a quiet, shy fish, distinct in outline, and easily recognised; but, like the gudgeon, destitute of any highly attractive features. The tench is the most tenacious of life of any fish in the collection, and never shows signs of exhaustion by gulping air from the surface. Tench are easily tamed, and take great pleasure in nibbling their proprietor's fingers. Mine eat bread and cheese with me, and nibble my fingers fiercely whenever I permit them.
C. Barbus.—The barbel takes the lead in the aquatic moustache movement. His barbs are really ornamental, and altogether he is a handsome but shy fish. The dorsal and caudal fins are very symmetrically shaped, and the lateral line arrests the eye when we contemplate his pleasing colours. If small newts, small carp, and minnows are kept in the same tank with barbel, they are likely to disappear one by one; for when all is quiet he makes his meal without seeking aid from the culinary art.
C. barbatula is perhaps the most interesting fish in the tank, considered as an individual. With no attractive colours, and with an outline as straight and rigid as a piece of bark, he surprises you with his graceful motions as he hawks along the surface of the glass, propelled by the easy undulatory action of the caudal end of the spine. Towards dusk he wakes up from his daylight stupor, and commences his queer, but pretty gyrations; and, after gliding ghost-like all round the tank, suddenly drops down as if dead, and rests on any leaf or stone that may receive him, remaining motionless, and in any attitude—on his head, his tail, or his side—that the power of gravity may give him. Then, with an uneasy fidgetting, he flounders up again, and off he goes, as graceful as before, his pectoral fins spread out like samples of lace, looking as much like an eel with frills as it it possible to conceive. When ascending, his motion is so undulatory that he may easily be mistaken for a smooth newt, going up for a bubble. Nor is our interest in him lessened by his displays of individuality of character. He is a savage on a small scale. When he is quietly dozing, half hidden among the sand and pebbles, throw in a small red worm, and, as soon as the water is tainted with the odour of this favourite food, he is awake and on the search. A triton seizes the worm, and shakes it as a cat would a mouse. The loach hunts him down, snaps at him fiercely, and tears the worm from his mouth, and woe to any minor fish that attempts to remove it from those bearded jaws. He flounders from place to place, shaking the prey as he goes, and stirs up such a cloud from the bottom, that the beauty of the scene is spoiled for an hour; at the end of which time you will probably find him gorging the prog, half of which still protrudes from his mouth, while two or three hungry minnows loiter about, looking wistfully at what they dare not hope to obtain.
It is a pity the loach is so delicate; it shows signs of exhaustion sooner than any fish in the collection. If oxygen fails, it comes to the surface to gulp air, and at last rolls over on its back, and pants in a way that is very painful to witness. Removed to a pan, under a jet of water, it soon recovers; but if long confined in a vessel the least overstocked, especially in warm weather, finishes his career by convulsive gaspings at the surface.
MINNOW, TENCH, & PERCH.
A curious species of loach, known as the spine loach, is met with occasionally in Wiltshire, in the Trent, near Nottingham, and in some of the tributaries of the Cam. Mr. Yarrell describes it; but as I have not yet had the good fortune to possess a living specimen, I can only refer to it casually.
C. cephalus.—The chub is a good aquarium fish. It is shy, but grows familiar under good treatment. Insects sooner attract it than any other food. Mr. Jesse says, that those in his vivarium throw off all reserve at the sight of a cockchafer, which they devour with eagerness.