Sawfish are predators of the sea. When a sawfish is hungry, it waves its sharp-toothed snout through a school of fish. Then, it lifts its nose and uses its mouth to inhale the injured victims.

Sawfish like this one are related to sharks, but they are technically rays.

Mote Marine Laboratory

Hardy populations of sawfish thrived in warm waters along coastlines around the world for thousands of years. Over the past 200 years, however, human actions have severely endangered sawfish. Threats include fishing nets that snag the huge animals, often by mistake. Compared with other fish, sawfish reproduce late in life and at slow rates. These traits make it hard for them to recover from overfishing.

Some people collect sawfish snouts as trophies: One snout recently sold for nearly $1,600 on eBay. Shamans, or priests, in some Asian cultures, use the toothy snouts in ceremonies to repel demons and disease. And sawfish are also a delicacy. A growing demand in Asia for the animal's fins for a pricey soup has contributed to the fish's disappearance.

New efforts now aim to revive sawfish populations. Beginning next month, an international agreement will provide protection for all seven of the world's sawfish species.

Scientists are hoping that it's not too late to save the sawfish. After all, there is still much to learn about these dagger-toothed animals.

Until 1998, "this fish had never been formally studied in the United States," says Tonya Wiley of the Mote Marine Laboratory in Sarasota, Fla. "We didn't know such basic things as where they live, what habitat they use, how often they reproduce, how many young they have—even what age sawfish are when they" begin reproducing.

Through historical studies and field research, scientists have become aware of how much the fish's numbers have dwindled. Today, there may be 90 percent fewer sawfish than there used to be. Wiley estimates that only 3,000 to 6,000 sawfish remain in U.S. waters.

Although there is much to learn about sawfish, recent studies are already producing results. For example, scientists now think that a species called smalltooth sawfish grow for 10 to 12 years before they first reproduce. A sawfish mom gives birth in shallow waters during the springtime. Then she disappears, while her young remain near the beach for months or even years.

As information accumulates, scientists hope to find better ways to protect this unique creature of the sea.—Emily Sohn