Morris Hinton, age 10, of Staten Island, N.Y., for his question:
HOW DID THE JELLYFISH RECEIVE HIS NAME?
One type of jellyfish found in ocean coastal waters is called the scyphozoan. Young are produced from eggs which then turn into polyps. The jellyfish grow from the polyps by a process called budding. They are arranged on each polyp like a stack of saucers. The jellyfish, when they reach the proper size, are released from the poly and they develop into adults.
Medusa is the name of a sea animal which is commonly called the jellyfish. There are many varieties with some as small as peas and others measuring about seven feet in length.
The jellyfish received his name from the jelly like material between the two layers of cells that make up the animal's body. This substance serves as a skeleton to support the fragile body wall.
Zoologists prefer the name "medusa." This title was suggested by a fancied resemblance the animal has to the snaky tresses of the Gorgon Medusa, the mythological maiden whose hair was turned into serpents that petrified anyone who looked at them.
The jellyfish's body resembles a bell or an umbrella. A short tube, which holds the mouth, hangs from the center of the body like the clapper of a bell. The edges of this tube form four projections which are called oral arms. Another group of projections, called tentacles, hang down from the edges of the body. Each type of jellyfish has a certain number and length of tentacles.
Coelenterates is the classification of jellyfish, a phylum that includes hydras, sea anemones and even corals.
Jellyfish are often pale orange, pink, blue or other light colors. They swim by expanding their bodies like the opening of an umbrella, and then pulling it together again rapidly. The movement squeezes water out from beneath the body and the jellyfish moves upward.
When the jellyfish's swimming movements stop, the creature will slowly sink to the bottom. On his way down he will catch small animals that touch his tentacles or oral arms. These parts contain stinging cells that explode when they touch a victim. The explosion drives tiny poisonous threads into the victim and paralyzes it. The victim is thenpassed to the mouth of the jellyfish and swallowed.
Some jellyfish can inflict painful and even dangerous stings to humans.
One type of jellyfish is called the sea wasp. This animal has a poison that is deadlier than any snake venom. Some victims die within three minutes after being stung. They are found in the coastal waters of northern Australia and the Philippines.