Artificial Method

Shad eggs differ essentially from trout eggs and require wholly different manipulation. They are much smaller and lighter. If a trout or salmon egg is dropped into water it sinks at once to the bottom, but a shad egg will almost float, and has but little more specific gravity that the water itself. Shad eggs are less than half the size of trout eggs and require as their best condition for hatching a temperature of from sixty-five to seventy-five degrees. They will hatch at a lower temperature but in such cases mature slowly, while eighty degrees of heat is as much as they can endure. When experiments were first made in their artificial propagation they were placed in ordinary trout troughs and much trouble was found in their management. If a current of water was turned on to the same extent as with trout they all washed over the end of the troughs, while if the supply was diminished so that they retained their places they died of suffocation. It was only after many different devices had been tried that the proper invention was discovered - a simple box with the bottom knocked out and replaced by a wire gauze netting. This box is suspended by floats of wood nailed on the sides so that the bottom is presented at an angle to the current, the degree of inclination being determined by the velocity of the current. The water striking against the screen enters the minute interstices, and lifting the eggs keeps them in gentle motion like the bubbles of air in a pot of moderately boiling water. All that is necessary is to attach these boxes one behind the other in a long row, anchor them in the river and fill them with impregnated spawn and the work is done. The continuous motion of the water passing around each egg and holding it suspended aerates it perfectly and makes its hatching a certainty. Hardly one per cent. of healthy eggs fail to hatch, and while the process is going on hardly any care or attention is required. Fish and eels cannot enter the boxes to prey, nor can the eggs be driven out by the water, and lost.

In the artificial manipulation of shad the parents are taken in seines from their spawning beds. The haul is made at night, at which time only can ripe fish be found in any considerable number. The captured fish are thrown indiscriminately into a boat and are stripped at once as they die quickly. They are afterwards sold in the markets. The eggs, which are caught in a pan with a little water in it after being allowed to stand for a few minutes until impregnation is complete, which is signified by their swelling in size and reducing the temperature of the water some ten degrees, are poured into the hatching boxes and left to themselves. Nothing more is required. In twenty four hours the black eyes of the young fry will be visible through the shell, and in from three to ten days they will be hatched. So rapid, simple and inexpensive is the process of shad culture. There are no flannel screens to be washed and cleaned every day or two as with salmon or trout; no rows of troughs to be examined laboriously with benumbed hands in winter weather; no weary waiting for months with every hour filled with danger; no contagious diseases or spreading conferva to be guarded against; no careful superintendence without which failure threatens; no particular selection of water or locality. The boxes are merely anchored in the stream, tied one to the other, the eggs are turned in by the hundred thousand, and in about a week there are myriads of minute but lively shad swimming about and begging to be allowed to grow fat and feed mankind. The eggs are as a score to one in abundance ; the loss is almost nothing, and the time, trouble and expense are infinitely less.

Nor is this all. When the trout is hatched he is encumbered with his umbilical sac for a month to such a degree as to be unable to protect himself, while the shad can be turned loose the day he is born. It is true that he has the same appendage, but it is a small one and does not seriously impede his motions. In habits also the shad fry exhibit their superiority over their more aristocratic cousins. Instead of seeking to hide their diminutive heads under every leaf and pebble, and in every out of the way corner playing at hide and seek with death, they with greater wisdom push out into the deeper water and broader stream. There in mid-river they float heading up against the current, taking the water with whatever of microcosmal food - invisible to man - it may contain into their mouths, feebly wagging their limp tails to keep them in position, and slowly settling down stream toward the ocean where they are destined to pass the next year or two waxing plump and fat for the benefit of man, but at no expense to him of purse, brain or muscle.

The discovery of the habits of shad fry was made in rather a singular way and exemplifies the dangers to which in their natural condition they are exposed. As with their hatching, so with their treatment afterwards ; it was natural to follow the system we understood and practiced with trout. The box containing the first results of the fish culturist's skill was towed near the land and some of the fry ladled out into the river. Instantly a crowd of minnows, killey fish, dace, chubs, shiners and all manner of small fishes swarmed from all directions and proceeded to devour their still smaller brethren. They arrived with astounding swiftness and in incredible numbers. Had a dinner bell been rung it could not have summoned a larger or hungrier congregation. In a minute not a shad remained alive to tell the tale : they had gone to the realm of the departed ; they had entered within the veil; they had sought the bourne from which no traveler returns. In other words, they were in the rapacious maws of a lot of little worthless fish which could do much harm but no good to any one. From the stomach of a little shiner not over an inch long, which was caught with a dip net, seventeen young shad were taken.

By this time it had become apparent that something was wrong, so the rest of the hatching was temporarily deposited in a small pond built of sand and pebbles on the shore of the river, while their case was taken under serious consideration. Next morning it was at first thought they had all escaped for they were not to be found anywhere in the body of the pond, but were finally discovered at its outer edge. A long narrow pond projecting into the river was then built, and pieces of white paper placed on the bottom so that the diminutive creatures could be more easily watched. Next morning they were again found crowded at the outer extremity. The problem was solved. Instinct had taught them to seek the deep water where their insignificance was their protection. Hardly a half inch in length and not more than a pin's thickness in breadth, they would escape unnoticed the monsters of three, four and five pounds weight which roamed about in the main current, while the terrors of the mighty deep would keep away their far more dangerous enemies of an inch or two in size. The big fish would not see them and the little ones could not follow them.