Laurie Johnston, age 14, of Columbia, Tenn., for her question:
HOW MANY KINDS OF RAY FISH ARE THERE?
There are about 350 kinds of fishes called rays in various oceans of the world. Included are the manta rays, sawfish, skates, sting rays, eagle rays and guitarfish.
The ray has been described as a flat bottomed, side wheeled shark built to navigate in shallow water.
Rays have very flat bodies. The pectoral fins, or side fins, are so large and fleshy that they can form a semicircular, sail like disk on each side of the body.
The ray's eyes are on the upper part of the fish while the mouth ana gill openings are on the underside.
Like the shark, the ray's skeleton is made up of cartilage and not bone. A gristle like material, cartilage is much softer than bone.
Many of the rays lay their eggs in small, hard cases that are called mermaids' purses. The cases have string like pieces on each of their four corners which are attached by the rays on the stalks of seaweed.
Most rays live in warm ocean waters and spend most of their time on the bottoms covered with sand. They eat crabs and sea worms although their favorite food is mollusks.
The skate is the most common ray found along the coasts of the United States. It has the usual flat ray body but it also has a short, thick tail. Skates vary in size from the two foot long common skate, or tobacco box of the Atlantic Coast, to the six foot long barn door skate which is also found in the Atlantic Ocean.
Also measuring about six feet in length is the gigantic skate of California.
The great manta, which is also called the devil fish, is the largest of all rays. This monster sometimes measures 22 feet across. Divers fear its fins that stretch out like wings and its front tips that stick out like horns.
It is easy for a great manta to break a diver's lines connecting him to the ocean's surface.
The electric ray, which is also called the torpedo ray, is able to give a person a strong shock. In the same class is the sting ray, which is sometimes called the whip ray. This creature has a long slender tail, the base of which is covered with a cluster of jagged spines. The sting ray can inflict painful wounds with this weapon.
There are about a half dozen species of sawfish. Some of them can grow to be 20 feet long. The sawfish has a long flattened snout. Inside the mouth are a set of powerful teeth.
Some rays lay eggs but in most species the young are born live.
Rays have small mouths and blunt teeth that are strong enough to crush the shells of crustaceans and mollusks.