Ailishia Mays, age 10, of Sarasota, Fla. for her question:

How many different octopuses are in the world?

About 50 different octopuses belong to the world's oceans. Most of them are the size of a man's fist. But some of the giants can stretch their tentacles 28 feet wide, meas¬ured from tip to tip. The tentacles are long, gristly arms, fitted with rows of small round suction cups. Every octopus has eight tentacles, and if he loses one, a new one grows in to replace it. His long arms are in a ring, where his neck would be if he had a neck.

The octopus is a mollusk animal, related to the clams and oysters. But he has no shell to protect his soft body, and no bones either. This makes him a rather shy chara¬cter, who prefers to hide from his foes. His sharp eyes watch for passing fishes. His tentacles grab them and stuff them into his mouth, which has a beak. He has fishy gills to take oxygen from the water. Usually he travels by jets of water, which he squirts from a pipe called his syphon. An octopus can change color or squirt out an inky cloud to conceal his hideaway.