With the help of a BBC camera crew and the loan of a high-speed video camera, University of California, Berkeley, scientists have recorded the swiftest kick, and perhaps most brutal attack, of any predator. The shrimp flail their club-shaped front leg at peak speeds of 23 meters per second to shatter the hard shells of their prey.

"The speed of this strike exceeds most animal movements by far," said biologist Sheila Patek, a Miller Post-doctoral Fellow at UC Berkeley. "It's insanely fast, but important for generating the forces necessary to crush its preferred food - snails."

When slowed down by a factor of 330, the video shows the mantis shrimp's fist pummeling the shell of a snail like a slow-motion glove smashing into the face of a boxer. Patek is currently conducting experiments which show that the blow yields a tremendous amount of force - well over a hundred times the mantis shrimp's body weight.

In a short note appearing in the April 22 issue of the journal Nature, Patek and her colleagues, graduate student Wyatt Korff and professor of integrative biology Roy Caldwell, report the record-setting strike and the unusual saddle-shaped spring in the hinge of the shrimp's striking appendage that makes it all possible.

This spring is technically a hyperbolic paraboloid, a structure similar to a Pringles potato chip. Very strong, especially when compressed, hyperbolic paraboloids have been used by architects to create structures that don't easily buckle. The nautilus employs this structural element to build a sturdier shell. In mantis shrimp, however, the saddle-shaped structure can also function as a spring, the UC Berkeley researchers found. It stores energy until a quick release propels the shrimp's club in a shell-crushing blow.

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Contact: Robert Sanders
rls@pa.urel.berkeley.edu
510-643-6998
University of California - Berkeley
21-Apr-2004