Worm Jaws Have Metal Power

Studying the jaws of marine worms may lead scientists to better ways of making synthetic materials.

Worms don’t usually get much respect. To most people, they are slimy, dirty, and gross.

But there is plenty in the humble worm to admire and inspire, say scientists in California. The jaws of marine worms, in particular, are incredibly strong. And new research is bringing researchers closer to developing hard materials that imitate nature.

This is a light-microscope image of the jaw, which is about 3 millimeters long.

H. Lichtenegger, et al./Proceedings of the National Academy of Sciences

Mammal jaws are made of bone. Worm jaws, on the other hand, are made mostly of protein. In a recent study, Galen Stucky of the University of California, Santa Barbara, and his colleagues found that a mineral called atacamite adds strength to the jaws of the marine bloodworm (Glycera dibranchiata).

In their newest study, the researchers compared the bloodworm to the clam worm (Nereis limbata), which digs around in the sand and mud. Both worms have protein-rich jaws, but the clam worm’s jaws contain just zinc while the bloodworm’s jaws contain zinc and copper.

An X-ray absorption image shows the highest concentration of zinc (dark area) near the tip of a clam-worm jaw.

H. Lichtenegger, et al./Proceedings of the National Academy of Sciences

The more zinc a part of the jaw has, the researchers found, the harder and stiffer it is. Even so, clam worms have softer jaws than bloodworms, which thrust their jaws into prey to inject venom.

Understanding what makes worm jaws so strong might lead to better designs for hearty, new materials, the scientists say. They’re also examining the hard beaks of octopuses and squid for similar kinds of inspiration, while other researchers are looking at sturdy conch shells.

With all the different materials that nature has created, it’s already solved many construction problems that come up for human inventers.—E. Sohn

Going Deeper:

Gorman, Jessica. 2003. Worm’s jaws show mettle: Zinc links may inspire new materials. Science News 164(Aug. 2):69. Available at http://www.sciencenews.org/20030802/fob5.asp .

______. 2002. Worm’s teeth conceal odd mineral material. Science News 162(Nov. 9):302. Available at http://www.sciencenews.org/20021109/note14.asp .

______. 2000. Conch yields clues for future materials. Science News 158(July 1):6. Available at http://www.sciencenews.org/20000701/fob4.asp .

More Stories from Science News for Students on Chemistry