Cindy Edwards, age 11, of Gastonia, N.C., for her question:
WHAT IS A DOGFISH?
In the past, the meat of the dogfish may have been fed to dogs because it was considered to be unsuitable for humans. Some experts suggest that this is how the dogfish got his name ¬though most language experts are not sure. Certainly the seagoing dogfish is a genuine fish and in no way related to the canine dog family. His name remains a mystery because he does not look or behave like the land dwelling dogs.
The various dogfishes are smallish members of the toothy shark tribe, ranging from 2 1/2 to 5 feet long. They enjoy a rather lazy life in shallow sea waters near the shores, though some of the larger species may venture out into deeper water. Often they congregate in large numbers, and fishermen detest them because they get tangled in their nets.
The sharks belong to a very ancient group that predates the more modern bony fishes. Their skeletons are made of strong, gristly cartilage, and their skins are not coated with neat, glassy scales. Instead of the usual round gill covers worn by other fishes, they have several pairs of gill slits.
The thick, tough skin is embedded all over with spiky little plates called denticles. The terrible mouth is under the chin, and the terrible jaws are set with rows of replaceable teeth. The dogfish has all these sharky features though on a somewhat smaller scale. However, he is no prowling predator of the deep ocean and hence less of a menace than some of the larger sharks. ,
The average dogfish usually grubs for a living from the floors of coastal waters. His six rows of sharky teeth can chomp crabs and whelks, tough squid and cuttlefish with no trouble at all. As old teeth wear down and fall out, new ones move forward to replace them so he has an unlimited supply.
In some dogfish, the fertilized eggs develop inside the female's body. She gives birth to a small brood of live baby dogfish, usually about 11 inches long. In other species, the female lays each egg in a tough oblong case, sometimes called a mermaid purse.
The average dogfish often supplements his diet with smallish fish, including other dogfishes. Though he has eyes, he does not use them to hunt, and some observers suspect that he may be partially blind. However, his super keen nose enables him to follow the scent of his prey, even when it swims a curving course through the water.