This section is from the book "The Goldfish And Its Systematic Culture With A View To Profit", by Hugo Mulertt. Also available from Amazon: The goldfish and its systematic culture.
Is also known as the fresh-water lobster, and should be killed whenever and wherever met, as it is very destructive to the eggs of fishes.
It will also occasionally catch a young fish, and often injure others by snapping at them, tearing away parts of the fins and flesh, thus rendering a beautiful and valuable fish wholly valueless as merchandise.
The main damage done by the craw-fish, however, is the undermining of the dams, which is not only annoying and costs much time and labor for repairs, but makes it possible for the fish in the several ponds to get mixed by passing from one to the other.
(Ranae var.) .
As the heading indicates, there is a recognized distinction between frogs, there being water-frogs, tree and grass frogs, the latter in no ways molesting the fish in the ponds, in reality on the contrary, making themselves very useful to the culturist by destroying harmful insects. The common frog is the one we have to guard against, both itself and all its varieties, whose destructive habits far outweigh the little benefit derived from them. Just as soon as they have completed their gradual metamorphosis, and become perfect frogs, they prey upon anything that has life, including young ducks, turtles, snakes and cray-fish, as well as fish. Besides this, the adult deposits its spawn in the ponds, and when the tad-poles are hatched, they consume a great percentage of the natural food found in the pond, thus depriving the young fish of proper nourishment, in this way being indirectly injurious.
The frogs are furthermore dangerous, through their habit of wandering in the night from one locality to another, during their spawning season, and thus often unconsciously introduce into the ponds, the spawn of minnows, which being adhesive, sticks to the skin of the frog, and is, of course, carried about by it.
The frogs make their appearance early in the spring, and it is at that time that they can be most effectually destroyed in the following manner: water is let into one of the ponds, to the height of several inches, in this pond they will collect at night, in order to deposit their spawn. Next morning, most of the frogs themselves can be caught with a dip-net, and the spawn also removed and exposed to the sun to dry up, by merely placing it upon the ground, where the sun can reach it. If this process is systematically carried out, during their spawning season, not many frogs will trouble the establishment during the season. When it appears that all are captured, the pond is drained off, so that any tad-poles that might have been hatched in it will die by being dried up in the sun.
In destroying the frogs the culturist must be careful not to mistake the common American toad (Buffo americanus) for the frog, as this innocent creature is worthy of our protection. They may very easily be distinguished by their color, which is brownish and yellow, the skin moreover being warty. Their eggs also differ from those of the frog by the manner in which they are joined together; those of the frog are found in one compact mass, a lump, in other words; those of the toad, in strings; the eggs of tree and grass frogs in sheets. If the amateur will bear these distinctions in mind he will have no trouble ridding himself of a pest and preserving a friend.
It will pay to remove the toad-spawn carefully, and put it into a pond where it can hatch unmolested, which is completed in June or July.
Toads in the neighborhood of ponds and gardens are a blessing, and should not, therefore, needlessly be exterminated.
One of the natural enemies of the frog is the water-spider, which attacks the young in the eye and kills it. Although the water-spider has been repeatedly mentioned as a friend, it is not out of place to keep an eye on him, as he also frequently catches young fish.
All the varieties of those tailed batrachians frequent the water in the spring, for the purpose of depositing their eggs or young - some being viviparous. In all the stages of their growth, from the tadpole state to the perfect animal, these creatures are destructive to both the fish eggs and the young fish, they should therefore be kept out of the ponds.
The newts spend their entire life in the water. In certain localities they may exist in such vast numbers that it is necessary to take especial precaution to keep them away.
Neither of these creatures, however, is harmful to man, the larger varieties living in the river, such as the water-dog and the hell-bender, excepted, nor are any of them poisonous.
They may, with perfect safety, be handled with the bare hand.
As the season advances various other enemies, in addition to those already mentioned, make their appearance. Most particularly must a sharp lookout be kept for
These will be found concealed near the water's edge, or in the corners of the several ponds. They lie hidden from view, the head only exposed, all the while playing the tongue in the water. This they do to allure their prey within reach, the fish mistaking it for a worm rush to their certain destruction.
The best means of exterminating them is by the use of some kind of fire-arm. A smooth bore, 22 caliber Flobert gun, loaded with a cartridge containing shot, and a good marksman at the proper end of it, generally makes a combination that forever prevents that snake from exercising his fishing propensities.
If young snakes are about, they may easily be discovered by placing pieces of board here and there about the ponds; these boards are lifted up in the morning, often revealing two or three of the little snakes that had sought shelter there, when thus found they are easily despatched.
A good snake trap was accidentally discovered as follows :
A wire coop made of 1/2 inch mesh galvanized iron wire netting, served as the dwelling of a couple of muskrats, which the children kept as pets. These having died, the coop was used to confine live frogs, and kept outside of the establishment in the water, just at the point it leaves the ponds.
The next morning a large water snake was found caught in the meshes of the wire, and dead.
It had evidently tried to get into the coop, and help itself to a frog or two, and was thus caught, the wire preventing the entrance of the entire body, the scales of the reptile at the same time precluding the possibility of retreat. Since then this trap, and smaller ones, have been used with very good results, and being simple they are easily made.
Following the snakes, and at the time the ponds are filled with water, one must be on the watch for fish-eating birds, among which are which, seeing the surface of the water below whilst flying above, are attracted by the glisten, and immediately descend to reconnoitre. These birds visit the ponds at regular hours, wade in the water and catch with consummate skill all the fish they can get. The fact that their stomachs are sometimes found to contain nothing else than crayfish must not mislead the amateur into the belief that they prey only on these crustaceans, as the following fact abundantly proves that they prefer fish whenever they can be obtained. A heron was seen flying towards the ponds; to secure the ever-ready shotgun from the lodge, sneak within range and fire, did not take more than five minutes' time. Yet within that short interval, the bird had captured and devoured three 2 1/2-inch long, brilliantly colored goldfish, which, though already dead when taken out of the bird's stomach, were still perfectly bright, showing conclusively that they had just been swallowed.
If these birds discover that fishing in the ponds pays well, they will become frequent visitors, and, if not killed, soon clean out the establishment. But, as before stated, they come at regular hours, thus affording the one on duty at the ponds an easy chance to be on the watch to kill or trap them.
This bird may likewise be expected to visit the ponds, but it generally advertises its arrival with a lusty kar-r-r-r-r-ack! that may be heard quite a distance.
It selects projections over the water, such as a branch of a tree, a post, or the outlet pipe of the ponds, from whence it shoots down upon the unsuspecting fish, seldom missing. It also supports itself upon its wings immediately over the water, darting down upon its prey with like success.
These birds, although not so easily shot as the crane or heron, may readily be caught in a trap, if the latter is somewhat concealed and laid on the post or outlet pipe, which the birds mostly frequent.
These reptiles are both extremely destructive; the latter, of course, not being found in the Northern States, need not be looked for in that locality. Neither of them, no matter how small, should be permitted to remain in or near the ponds.
Not only do these animals destroy the dams of the ponds, but they will also destroy the entire stock of fish, if not stopped in time. Luckily for the fish-culturist, they are easily mastered. One or two muskrat traps of the old-fashioned style (Hawley & Norton's No. 1), used by professional trappers in the Far West, can be procured at almost any hardware store for thirty cents apiece, the chain included. The muskrat holes are looked for and will be found leading into the bank and a little below the surface of the water. At a short distance from such a hole (the length of the chain on the trap), a peg is driven securely into the ground, and the free end of the chain fastened to it. The trap is then set without bait, and laid a little to one side immediately into the hole, in such a manner that the animal in going in or out is obliged to tread upon the plate that springs the trap and over one or the other end, thus it is always caught by one of its legs.
If the trap is placed at right angles with the hole, so that the animal has to walk over the bows, these latter, in coming together, will throw the rat upwards, and fail to catch it.
It is advisable also to catch the muskrats in the surrounding neighborhood of the ponds, as they make excursions during the night to the ponds in order to fish.
This long list of enemies may be increased by adding the raccoon, the mink, and water-fowls such as ducks, geese, and swans.
In stores where fish are kept in tanks they must be watched and protected from house-rats and cats, both of which will occasionally make a descent upon the tanks if not prevented.