Rick Waldner, age 15, of Hillcrest, Alberta, Canada, for his question:

Is there really a  sea cow?

There is a certain small, stately character called the sea horse    who resembles the horsey knight used in the game of chess. The animal called the sea cow resembles a dairy cow in many ways. However, she has no hoofs or horns and the greenery on which she feeds is floating water weeds. She is known by several other names. But one sure place to find her is in the gentle waterways of Florida.

Sea cows were noticed in warm, shallow coastal waters way back when people still believed in mermaids. Sailors mistook them for legendary mermaids that were supposed to sing siren songs to lure ships to destruction on treacherous shoals. Scientists recalled this fanciful notion when they classified the various sea cows in the Order Sirenia. However, on closer inspection, the big blubbery sea cow shatters our concept of the glamorous mermaid siren.

The West Indians called their sea cow the manatee and this name is now used for those that live in the coastal waters off Florida, Central and South America and West Africa. Their close relatives the dugongs live in the Red Sea, along the coasts of East Africa and around Pacific islands as far south as Australia. All these sea cows somewhat resemble porpoises, though they are not related to this cetacean order of whales, or to the seals.

The manatee of Florida waters has a huge tapering body often 15 feet long. His wide tail flukes spread sideways, like those of the whales. He has no hind limbs, though he has long, strong front flippers with bendable elbows and the round tips have fingernails. His large, shapeless face has a button nose with a poor sense of smell, small eyes with poor vision and loose sagging lips adorned with whiskers. His toothless lower jaw has hard, horny gums. He may have upper incisors and perhaps grinding teeth in his cheeks. The male dugong usually has a stubby pair of tusks in his upper jaw.

Our American sea cow dangles his big body down in the water and curves his tail slightly forward. In this position, he maintains his balance while he browses on water¬ weeds that choke the surface of the shores and inland waterways. His mobile upper lip is divided down the middle and used to grasp bunches of vegetation. Feeding occupies most of his time, for he needs 100 pounds of food a day, aid every four minutes he must surface for a breath of air. The manatees of South America often wander far up the Amazon and Orinoco rivers. Their kinfolk on the far side of the Atlantic often ascend the wide rivers of West Africa.

The sea cows are gentle characters and pitifully easy to catch. In the past, they were hunted for their meat    until their numbers were reduced to the danger level. Now they are protected by law and the populations are increasing. However, the return to safety is slow. The dugong bears only one calf in about two years, though the manatee may sometimes bear two. The newborn calf weighs 40 to 60 pounds and depends on mother's milk through his first 18 months.