David Turner, age 12, of Omaha, Nebraska, for his question:

What exactly are dogfishes?

The various dogfish are smallish cousins of the hungry sharks and the bat shaped rays. They range in size from 2 1/2 to 5 feet and most of them live fairly near the shorelines of mild and tropical seas. As small sharks, they belong in the Class Chondrichthyes    a scientific name meaning the cartilage fishes. All these creatures of the sea have skeletons of gristly cartilage. They are descended front early fishes that teemed in the ancient seas of some 300 million years ago.

Most of the dogfish are grouped as spiny or smooth, depending upon whether they have spines in front of their dorsal fins. They are long and slender fishes and mighty powerful hunters. As a rule, they have about six rows of sharky teeth and all of them have sharky gill slits. Dogfish prey hungrily on other fishes, dead or alive. They are regarded as pests because they devour food fish and damange fishing nets. Before the days of synthethic vitamins, they were hunted for the rich oil in their livers. Some people still eat dogfish meat, though nowadays most of those caught are processed to make soil fertilizers.