LESSON XXXVIII.
SEA-STARS.
Now we come to another animal who seems to be made on the star plan. Here you see pictures of him in the water, where he has his home. Is he not a pretty thing?
The jelly-fish has one of his names from his shape, and another name from his power to sting. This fish gets one name from his shape,—star-fish. And he has a long, hard name from his coat. His coat is a thick, tough skin. It has upon it prickles much like those of a hedge-hog. Most of them have five rays, or ten, because each single ray has been made into two, and so on.
All of the star-fish do not keep to the plan of five. The sun-star has twelve rays. He is of a splendid, bright-red color. These animals seem to be made on the star plan; the grown-up sea-stars show this shape most clearly, but it is never perfect; the young ones are two-sided, not star-like.
From their general shape they are called “stars,” from their skins, “rough or hedge-hog coated.” This skin is really their skeleton: they have their bones outside like the crabs and some other creatures.
The Ray Family at Home.
The Ray Family at Home.
The crab’s skeleton is hard, the sea-star’s is more like a tough skin filled with little plates or spikes of shelly stuff. Sometimes these little plates lock together, sometimes they merely lie near each other, so some of the stars have much softer coats than the others. In the water these coats are tough and bend like leather. When they are dry they are brittle. If you want a dead star-fish to bend, drop it into water.
I will tell you of some kinds of star-fish, and then will tell you how they grow.
In the picture you see a star-fish withthe thin, crooked rays, or arms. He is called a sand-star, because he likes to lie close to the sand on the sea-bottom. He is of a sand color.
The one with the curled arms, like plumes, is called the brittle-star. That is because he breaks so easily. He is a very queer fellow. When things do not please him, he drops all to pieces. It would be a queer thing, if, when you feel cross or afraid, you could throw yourself down and fly to pieces, jerking off your head, your arms, and your legs!
You have heard how crabs can drop off a claw, and then another grows out. You also know that a spider does not mind much about losing a leg or two. These facts cause us to feel sure that these creatures do not suffer pain at the loss of a part of their bodies. If the loss of legs, claws, or rays caused pain, these animals would not be so ready to drop them.
There is no other creature that breaks itself so readily and so entirely as the brittle-star. It will throw off all its rays, and they will float away in many directions, while the little disk is left alone to sink or to float.
When the star-fish loses one or more, or even four rays, others will soon grow. All the animals of this family renew lost parts even more easily than crabs do.
It is very hard to get a brittle-star out of the water. As soon as it feels a net or scoop or the upper air about it, or a pail of fresh water rising gently around it, it breaks into many pieces.
On the end of every ray is a little sharp eye. When you frighten Mr. Brittle-Star, off swim his legs, every one by itself, and each has its one eye to look out for it. I never saw anything else so queer; did you?
The strong, prim-looking star-fish, with five points, is called the cross-star. It is the common, or pattern star-fish. There are many other kinds. I will tell you in the next lesson of one very pretty kind. You must go to larger books to learn all that is known about these strange and lovely creatures.
We will look at the model, or cross-star. Turn the animal over. The mouth is in the centre of the under side. Do you not find there is a seam, or groove of the hard skin, all the way down the centre of each ray? From the mouth a nerve runs down to the point of each of the rays.
Along the centres of the under openings in the rays are set very, very many little blunt points. These points are like tiny tubes close together. It is on these that the star-fish can walk or creep on the bottom of the sea, or over rocks. The star-fish seek their food as they crawl slowly about.
Star-fish are very greedy. They are always hungry. They make the fishermen much trouble by eating the fish-bait off their hooks. They also devour oysters. When they get into an oyster-bed they are as bad as the drill. When an army of star-fish go to a part of the coast where oysters grow, the oysters are soon killed.
The star-fish are of many bright and pretty colors. They are green, brown, gray, red, pink, or with several colors on the same star.
When they are dead, the flesh, which has much water in it, dries away. The tough shell-like skin is left. You can dry them by pinning them on a board. Leave them for a few days in the sun and wind. If you do not pin out the rays, they may curl up.
They look better kept in alcohol, but that is not a good way for children. I fear the bottles would soon be broken.