Katherine Goba, aged 9, of Lancaster, Penna., for her question:

How does a starfish eat?

Have you ever tried to open a live oyster? If you have, you know that it is no easy job. The oyster seems to resent having its two shells pried apart. The harder you try to get them open, the harder he grips them together. This is also true of clams, mussels and other two‑shelled creatures. It takes a strong arm, a special knife and a special knack to open live oysters, clams, mussels and such.

Yet the pretty little starfish can do it all by himself. For these shellfish are his favorite food. True, he has five or more strong arms for the job. But none of them are more than a few inches long. A starfish no more than six inches from do to tip can open a live oyster.

The underside of his pointed arms are covered with tiny suckers. He begins by getting a good grip over the lip of the oyster shells. Naturally, the oyster shuts himself up tight as a drum. But the starfish gets an arm or two on one side and an arm or two on the other.

Then begins a tug of war. The oyster exerts his muscle to keep his two shells shut. The starfish exerts his muscles to get them open. Slowly and steadily the pressure goes on. The oyster can bear it no longer. It gives way. The starfish pries the shells apart. Dinner is served.

The mouth of the starfish is a round hole on its underside. It is in the middle of its spreading arms. And it opens straight into the stomach. There is no throat. In fact, the starfish can send Its stomach out through its mouth. This is how it gets the oyster out of the shell. The starfish simply turns its stomach inside out, reaches down and engulfs the oyster.

Though clams, mussels and oysters are the starfish’s favorite food, he also enjoys snacks of smaller shellfish. He sometimes catches sea snails and creatures with paper‑thin shells. These little fellows he does not stop to open. He swallows them ‑whole, shell and all. Later, he spits out the shelly fragments.

The starfish is quite an acrobat, though in slow motion. He walk like a dancer on the tips of his toes. He can flip over on his back when stranded. He can wriggle through a hole no wider than one of his arms. But he is not quick enough to catch anything much faster than a clam ‑ or an oyster which does not move at all.

Starfish are great pests in oyster beds. In days gone by, fishermen tried to destroy them by tearing them apart. The strange result was more starfish than ever. For the little fellow can grow a new arm when he loses one. He can even grow a whole new body from one single arm.