BOSTON, Oct. 16 (UPI) -- New research has revealed the significance of seals' whiskers. Their shape, scientists at MIT say, are what make seals such effective hunters.
Generally speaking, whiskers play a similar role for all the mammals from whose cheeks they protrude -- a tactile role, offering the sense of touch to even those without hands. Among other abilities, whiskers help mammals orient their snout, detect movement and textures and maintain balance.
But seal whiskers appear to be especially important and precise. A new study, published this week in the journal Smart Materials and Structures, presents the unique wavy shape of a seal's whisker as key to its efficacy.
When a fish swims nearby, its movements disturb the ocean water. The frequencies of the disturbance cause the seal's whiskers to vibrate at a matching pace. These vibrations are translated by the seal's brain to reveal the passing prey's size, shape and trajectory.
The whiskers' bulge in a pattern like peas in pod. The shape is what allows the whisker to pick up only external vibrations, uninfluenced by the seal's own movements.
"It's marvelous to see this intricate pattern, it's not just a straight antenna -- it's a perfect sinusoid," lead study author Michael Triantafyllou, a mechanical engineer at MIT, said in a press release.
Only a few seal species have similarly wavy whiskers. Sea lions and walruses have straight whiskers.
Researchers built oversized plastic whiskers and tested their vibrations underwater to better understand how they work. The wavy shape has a quieting or dampening effect, limiting the whiskers' vibrations as the seal swims through the water.
"It's like having the ability to stick your head out of a car window, and have there be no noise, so that your ears don't ring: It's a quieting effect," Triantafyllou explained.
Researchers believe the whisker's shape could inspire better-performing underwater antennas on sensors used to track fish and other sea creatures.