Mary Ellen Holoweiko, age 14, of Lansing, Michigan, for her question:

Which is the largest fish in the sea?

The biggest animal that ever lived in our world is the blue baleen whale of the deep ocean. But he must be disqualified from this contest because, as everybody knows, he is not really a fish. However, the biggest true fish is as gentle as the giant whale.

When we hear the word shark, we think of dreadful man eating creatures, and shudder. Actually, about 235 fishes are classed as sharks and only 12 of them are dangerous man eaters. This, of course, is more than enough serious enemies to have in the sea. Every year, about 400 heedless swimmers and shipwrecked sailors become food for hungry sharks. As a rule, the greedy menaces prowl in warmish seas and very often they strike without provocation. Local authorities issue shark warnings and sensible swimmers and boaters pay strict attention. The biggest and meanest man eater is the 20 foot white shark. Beware, for he can gobble you down in a single gulp.

There is nothing scary, however, about the whopping whale shark. And this gentle giant happens to be the biggest fish in the sea. The rather lazy monster has a dark skin speckled with white spots. He enjoys his leisurely life in warm and tropical seas where he spends a lot of time basking on or just below the surface. Seen from above, he looks somewhat like a flurry of snowflakes in a big black cloud. We have nothing to fear from him, and adventurous swimmers have ridden on his back without coming to harm.

Sometimes a whale shark reaches a length of 50 to 60 feet. Such a fellow may weigh around 20 tons. He is rather a flattish shaped fish with a wide head and a mouth like an over sized slot in a mail box. It is a very different mouth from the toothy jaws of most sharks. He has teeth, but he does not use them in sharky fashion to tear apart and gobble great gobs of meat. In fact, he lives on floating plankton and an assortment of very small fishes. He fills his great mouth with sea water and strains the edible morsels through a system of rakers in his gills.

Only one other shark lives on this kind of food. He too is a whopper, second in size only to the whale shark. This harmless eater of plankton and small fishes is the basking shark. He prefers to live in the cool waters of the Arctic but he also enjoys the warmth of the sun. He is called the basking shark because he spends so much of his time basking on the surface of the sea. This fellow is the second largest fish in the sea and he may reach a length of 40 to 45 feet.

A big whale shark often drifts lazily beside a fishing boat, perhaps curious to inspect and classify it. He is not scared off by whooping and hollering and one crew had to use a pole to shove their boat away from a whale shark who refused to budge. During the mating season, the basking shark travels with a group of his friends and relatives. Sometimes they stray southward and fisherman around the British Isles may snarl one in a net. And the best net made for catching herrings can be ripped into ruins by a 40 foot fish.