Do sharks lose teeth like people do?

September 14, 2006

They sure do. Surprisingly, sharks lose or break teeth easily, but the teeth are quickly replaced from a warehouse of five to 15 rows of spares continuously produced and stored in the shark’s jaws. New teeth can move to the front within 24 hours. Some sharks can produce more than 10,000 teeth in a lifetime. It’s estimated a tiger shark produces up to 24,000 teeth in a 10-year period!

Different sharks have different shaped teeth. Some are long and curved for holding slippery fish. Others are serrated for cutting. Some sharks like the smooth dogfish have teeth designed for crushing.

Sharks can’t chew and must swallow food in chunks. They eat at one- to two-day intervals and are more active during twilight and night. Most feed on sick or injured animals. Diets vary from fish to stingrays to seals. The examination of the contents of one tiger shark’s stomach revealed half a crocodile, a sheep’s hind leg, three gulls, two cans of unopened peas and assorted bike parts. The basking shark, one of the largest sharks reaching 45-feet in length, has very small teeth and feeds exclusively on tiny plankton.

According to divers, sand tiger sharks are common around wrecks in North Carolina waters. Fortunately, the teeth of sand tigers are not adapted for taking large prey.

Shark teeth found on beaches are most likely not from sharks swimming today. They are fossilized, ranging from 20,000 to 50 million years old. The teeth are usually very dark, black or gray, but can be brown or creamy. Color variation is due to different environments and sediments where teeth were found. Size and shape vary with species. If the tooth is in fairly good condition, it can often be traced to its owner.

The teeth of about 14 shark species are found on Carolina beaches, including those of the great white, hammerhead, tiger, bull and lemon shark. Good hunting grounds are Fort Macon State Park, Atlantic Beach; Topsail Beach near Jacksonville; and Hammocks Beach State Park near Swansboro. The best time for hunting is at low tide or after storms.

Visitors can also search for shark teeth and other ancient marine animal remains at on-site fossil digs at all three of the state’s public Aquariums. Serious fossil hunters may want to visit the Aurora Fossil Museum on Highway 306 in Beaufort County.

Sharks are fascinating creatures with an average natural life span of 25 years. Their biology has remained virtually unchanged for millenniums; however, today their populations are declining.

As top predators, sharks play a vital role in the health and balance of the marine ecosystem. If overfished, populations can remain depleted for decades because of sharks’ slow growth and reproduction rates.