Norman Cooper, age 9, of Gadsden, Ala., for his question:
WHY DO WE CALL THEM CATFISH?
Catfish is a name given to a large group of fish. In fact there are over 2,000 species of catfish and many of them have sharp spines on the back fins and on the fins near their gills. Unlike most fish, catfish have no scales over their skin.
Most catfish have two to four pairs of whiskers. These whiskers, called barbels, resemble the whiskers of a cat. The resemblance to the cat is what gives the fish his name.
The spines on small kinds of catfish, by the way, give off a poison when they pierce another animal.
The largest species, called the European catfish, may grow to be more than 10 feet long and weigh as much as 400 pounds.
On the other end of the scale is the pygmy corydoras, a catfish that measures only an inch to an inch and a half in length. This tiny fish weighs about a tenth of an ounce. Many people keep these small fish, often called glass catfish, in home aquariums.
Catfish are found in most parts of the world. Some live in fresh water while others are saltwater fish.
Most catfish live in quiet waters and they feed on tiny animals and bits of animal flesh. They find their food near the bottom of a pond or a slow moving river.
A few species of catfish live in swift streams. They include the channel catfish, which lives in North America. Such catfish eat other fish, frogs, crayfish and insects.
Many people consider catfish to be one of the most delicious of all fish to eat. In the eastern United States, and especially in the Mississippi River Valley, fishermen try for channel catfish, blue catfish and yellow catfish. The bullhead, a type of catfish, is also an extremely popular food fish in the eastern and southern states.
Catfish farms, most of them in the Southern states, raise channel catfish for use as food.
Some types of catfish have unusual features or ways of life. The armored catfish, as an example, has overlapping bony plates that cover its body. The upside down catfish actually swims upside down. The electric catfish can send out a strong electric shock.
And then there's the eelcat, a West African catfish that is so long and slim that it resembles an eel. The candiru, a small South American catfish, swims into the gills of larger fish. It then rips the gills with its sharp spines and drinks the victim's blood.
Among some species of ocean catfish, the male carries the eggs in his mouth and does not eat until they are hatched.
The walking catfish of tropical Asia can move overland to another body of water if its pond dries up. This fish pushes itself along the ground with its tail, using its strong front fins to lift the front part of its body.
The walking catfish has gills, but it also has lunglike breathing organs. These organs enable the fish to stay out of water for days if surroundings are wet or rainy. Even under dry conditions, the fish can survive out of water as long as 12 hours.