WAS IT DESIGNED? The Byssus of the Marine Mussel

LIKE barnacles, marine mussels attach themselves to rocks, wood, or ship hulls. However, unlike barnacles, which fasten themselves tightly to a surface, marine mussels dangle by a network of thin filaments called byssus threads. While this method increases the mussel’s flexibility for feeding and migration, the threads seem too flimsy to withstand the impact of ocean waves. How does the byssus allow the mussel to hang on and not be swept out to sea?

Consider: Byssus threads are stiff on one end, yet soft and stretchy on the other. Researchers have found that the precise ratio used by the mussel​—80 percent stiff material to 20 percent soft—​is critical for providing the strongest attachment. Hence, the byssus can handle the force of dramatic pulling and pushing by marine waters.

Professor Guy Genin calls the results of this research “stunning,” adding: “The magic of this organism lies in the structurally clever integration of this compliant region with the stiff region.” Scientists believe that the design of the byssus threads could have uses as diverse as attaching equipment to buildings and underwater vessels, connecting tendons to bones, and sealing surgical incisions. “Nature is a bottomless treasure trove, as far as adhesion strategies go,” says J. Herbert Waite, a professor at the University of California in Santa Barbara, U.S.A.

What do you think? Did the byssus of the marine mussel come about by evolution? Or was it designed?