LESSON XLIV.
FRY AND SCHOOL.
A fish comes from an egg, as a bird does. There are one or two kinds that are born as little live fishes. But the rule is that the fishes hatch outof tiny eggs. The mother fish drops these eggs in the water, or carefully lays them in some place which she prepares for them.
A CURIOUS CRADLE.
A CURIOUS CRADLE.
After they are laid, these eggs are called spawn. Before they are laid, they lie in a solid mass together. There are many thousands of them in each mass, and they are then called roe. I have told you of the wonderful number of eggs laid by insects. But fish surpass even the insects in the number of eggs.
These eggs are subject to very many dangers. Fish, crabs, and water-fowls eat them. The waves may dash them ashore, and so they will be dried up. Therefore it is needful that there should be a great many, so that after all disasters a large number may hatch.
The eggs of fish are of a pearly white, or a cream color. They are covered with a kind of glue, so that they stick together. They also stick to weeds, or rock, or sand, where they are laid.
There are very few fish that carry their eggs about with them, after they are laid. The fish presses its body against the eggs, which stick to it, and are carried about, until they hatch. You have read of the crab which took care of its eggs in this way.[33]
As the little fish grows within the egg, the soft skin-like case becomes very thin. When the time comes for hatching, the little fish breaks the case, and comes out. As a general rule, the little fish, just out of the egg, looks and acts like the parent fish. But there are some that change much between their first and their full-grown states.
Let us now look at some curious fish eggs and fish nests. Of all the fin family, the dog-fish has the most curious cradle for its young. The egg-case of the dog-fish is a horny bag, or purse. It is of a gray or blackish color, about an inch wide, and two inches long. At each of the four corners, it has a long, stiff, curly stem.
The mother dog-fish swims near the shore to lay hereggs. She selects a weed, branch, or piece of tree, lying in the water. To this she ties her egg-cases by means of their long stems, or strings. She does this by swimming round and round the twig to which she means to fasten the case. As she drops the case in the water, she ties it, or binds it, by drawing with her the curly ends, as she swims, about the branch.
She lays a number of these purses in a place. Then she swims off and leaves them. It is lucky that she does, for if she stayed near them, she would eat the little fish as soon as they came out!
I have seen a dog-fish tying its eggs to a branch lying under water, and it was a queer sight. When the baby fish has grown large enough to leave the case, it makes a little opening on one end, and creeps out.
The skate, that is a cousin of the dog-fish, lays a case much like this. But the case of the skate is of a shape more nearly square. It has four sharp, curved horns, not long, curly ends; and the little skate comes out of a hole in the middle, never at the end.
Another sea-fish, the mackerel, has no such protection for its eggs. It drops thousands of them on the water, and they look like tiny pearl beads. Theysink to the bottom. As they are sticky, they cling together, and to the sand, until they hatch.
That prettiest of fish, the trout, which lives in so many clear, shady streams, where there are deep, quiet pools to bask in, is very careful of her eggs. The mother trout sinks to the bottom of some clean stream, and selects a nice sandy place. Then, with her tail, she fans out all the coarse sand and gravel. If there are larger bits of pebble, she carries them off in her mouth.
When she has made a nice smooth little nest, like a cup, she drops her eggs into it. Then she covers them lightly with gravel, so that they will not be floated away. When she has finished one nest, she swims off to make another.
The black bass of our lakes and ponds makes a smooth bed for its eggs. It prepares this bed in the shadow of a stone or sunken log. Several bass will go together, and select and clear out such a bed. Then they will lay their eggs there, and for days, until the eggs hatch, will swim about near, to keep watch over them. Eels, cat-fish, perch, and suckers, come to eat these eggs, and the big bass drive them away.
The pretty perch does not take such care as this of her eggs. She drops them in long chains, amonggrasses, and leaves of water-plants, at the edge of the pond. When the yellow cowslips are in bloom, you can find these eggs among the water-plants, like strings of fairy beads.
When the baby perch come from the eggs, they are very nimble, and begin at once to eat. When they are no longer than the nail of your little finger, it is funny to see them in the water, darting after the living atoms that serve them for food.
They see and know these tiny things in the water, and pounce upon them with wide-open mouths.
The little fish, from the time they are out of the egg, until they are about half grown, are called fry. Some fish, as the salmon, get different names at different periods of their growth. A great many fish together are called a school. Thousands of fish will come leaping, rolling, and tumbling along in the water, and we say it is a school of fish.
FOOTNOTES:[33]Nature Reader, No. 1, Lesson 3.
[33]Nature Reader, No. 1, Lesson 3.
[33]Nature Reader, No. 1, Lesson 3.