Q. Do sharks ever lose teeth?

A. Yes, but they have plenty in reserve. Sharks produce many teeth during their lifetime. It's estimated that a tiger shark produces up to 24,000 teeth in a 10-year period.

Sharks not only have rows of functioning teeth, but also 5 to 15 rows of back-up teeth, which can move to the front within 24 hours. Some sharks have very small teeth for straining rather than feeding.

The whale shark, for instance, has several thousand teeth about one-twelfth of an inch long in about a dozen rows. This gentle giant catches small crustaceans and fishes and strains them out of the water using sieves on its large gills.

The teeth of about 14 shark species are found on North Carolina beaches. Among those are the great white, hammerhead, tiger, bull and lemon sharks. With razor sharp teeth and powerful jaws, sharks have recorded biting pressures as high as 17 tons per square inch.

Sharks' teeth found on beaches are probably not from sharks swimming around today. Most likely they are fossilized teeth that, by some estimates, could be thousands or even millions of years old. The size, shape and color vary with species. If a tooth is in fairly good condition, it can often be matched to the species of shark that lost it.

The state operates three public aquariums: one in Pine Knoll Shores, another at Fort Fisher and a third on Roanoke Island. The aquariums are administered by the North Carolina Department of Environment and Natural Resources, and are designed to inspire appreciation and conservation of North Carolina's aquatic environment.

For more information about the Aquariums, visit www.ncaquariums.com, or call 800-832-FISH.

Sherry White works for the public affairs office of the N.C. Aquariums.