Cheetahs are traditionally known as the fastest animal on Earth, but these sleek felines are no match for the lowly mite, by one important measurement. Mites were seen traveling 20 times faster than cheetahs, in terms of body lengths per second.
Paratarsotomus macropalpis is capable of running up to 322 body lengths per second, compared to roughly 16 for cheetahs. If humans raced at the same speed, runners would travel more than 1,300 miles per hour. This is faster than the speed of sound at sea level.
These tiny creatures are only about the size of a sesame seed, and were recorded under both laboratory and field conditions.
Smaller animals travel faster as a measure of body length than larger organisms, as a general rule. The tiny runners are also capable of making a greater number of strides per second. Biologists believe there is an upper limit to how quickly legs, and the tiny creatures, can move.
Jonathan Wright, a biology professor at Ponoma College, was studying the biochemistry of muscle movements when he became interested in the relatively speedy mite.
"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," Wright said.
Samuel Rubin, physics major at Pitzer College in his junior year, directed much of the field research documenting the behavior of mites in the wild. When P. macropalpis was observed by Rubin and his team, they realized they had witnessed a world record performance.
"It was actually quite difficult to catch them, and when we were filming outside, you had to follow them incredibly quickly as the camera's field of view is only about [four inches] across," Rubin said.
Amazingly, the tiny mites were seen running on concrete in temperatures up to 140 degrees Fahrenheit. The creatures performed quick stops and turns as they sped along surfaces hot enough to kill most living beings.
"[L]ooking deeper into the physics of how they accomplish these speeds could help inspire revolutionary new designs for things like robots or biomimetic devices," Rubin stated in a press release.
The species P. macropalpis was first discovered nearly 100 centuries ago, in 1916. Still, not much is known about the mite, including feeding habits. The species is native to Southern California, where it is commonly seen on sidewalks.
Other species are also known to be speedier than a cheetah. The Australian tiger beetle can run at 171 body lengths every second.
Rubin presented the findings at the Experimental Biology 2014 meeting on 27 April. This meeting, held in San Diego, was attended by 14,000 experts from a diverse range of bio-sciences.
