Species of mite apparently the fastest creature in the world

Who would win a race: a cheetah of Paratarsotomus macropalpis, a type of mite? The answer depends on what kind of race it is. In a distance race, the remarkable bound of a slender cheetah is unbeatable. But if the race is measured in "body lengths per second," nothing outpaces the mite. That's right, when speed is measured relative to body size, nothing in the world is faster than Paratarsotomus macropalpis. "It's so cool to discover something that's faster than anything else, and just to imagine, as a human, going that fast compared to your body length is really amazing," said Samuel Rubin, a junior physics major at Pitzer College who helped conduct the research. "But beyond that, looking deeper into the physics of how they accomplish these speeds could help inspire revolutionary new designs for things like robots or biomimetic devices." Rubin assisted Jonathan Wright, a professor of biology at Pomona College, in studying the rapid leg movement of the mite. The student researcher and his professor observed the mite, both in the lab and in its natural environment, using speed cameras. Wright said keeping the mite in the camera frame was exceedingly difficult. "We were looking at the overarching question of whether there is an upper limit to the relative speed or stride frequency that can be achieved," Wright explained. "When the values for mites are compared with data from other animals, they indicate that, if there is an upper limit, we haven't found it yet." Rubin presented the duo's findings to attendees of the Experimental Biology 2014 meeting in San Diego on Sunday.