Robin Weiss, age 11, of Valinda, Calif., for his question:

If a sardine is not caught, what does he become?

Sardines look like miniature herrings, mackerel and pilchards, and this is just what many of them are. The tender, tasty morsels are teen agers of the fish world, and those that are not caught and stuffed into cans grow up to become bigger food fish.

The original sardine was a teen age pilchard who swam in the Mediterranean Sea and went out into the warm eastern Atlantic Ocean. In roman times many of his relatives were caught off Sardinia, and most likely his name was borrowed from this Mediterranean Island. The sardine who escaped capture grew up to become a graceful, seven inch pilchard  and then his luck ran out. He, too, was caught and sent to market along with tons of other pilchard food fish.

Teeming schools of pilchard still migrate between Africa and the British Isles. The eggs are laid when the water reaches just the right temperature. This may happen when the fish are north or south, and no one knows where to expect the floating masses of trillions of eggs. Millions are devoured by hungry fishes, but millions of them survive and hatch into little fishes. Tons of these pilchard sardines are caught and sent to the fisheries of France, Spain and Portugal. There they are squeezed into flat cans and packed in rich olive oil. a first cousin of the mediterranean sardine migrates off our pacific shores between Alaska and Baja California. In the 1930s, california fisheries caught a million tons. Of these sardines a year. Most of the rich harvest was crushed to make oil and cattle food. This plunder discouraged the pacific sardine, and the teeming population dwindled away. Someday, we hope, their numbers will increase again.

Pilchard sardines are not world travelers. But other sardines can be found in almost all off shore fishing waters. Some are teen agers of various mackerel type food fish. Moat of them are teen age herring, and some experts claim that the herrings in the sea outnumber every other species of backboned animal in the world. A school of Atlantic Herring array teem with more than 3 billion members, swimming side by side, nose to tail through miles of surface waters.

Herring is the world's most important food fish  delicious, nutritious and bountiful. Almost 2 million tons of herring are taken every year from the world oceans, and much of this wholesome harvest is sardines.

Chances are, a can of sardines in the market is stuffed full of young herrings. As a rule, the heads are removed, and the silvery little bodies are jam packed in oil or tomatoes, mustard or some other flavorsome sauce. In the sunny surface of the sea they absorbed vitamins and minerals and grew bodies rich in proteins and calcium. And we eat thebe tender, tasty young fishes whole  bones, tail and all.