A team of scientists has discovered that tiny trap-jaw spiders, which belong to the Mecysmaucheniidae family, have the ability to strike their prey at lightning speeds. The unique spiders, which don't seem all that special to the naked eye, live exclusively in New Zealand and southern regions of South America and are among the fastest on Earth.
The team, led by Smithsonian scientist Hannah Wood, used DNA analysis to reveal that these high-speed, super-powered strikes evolved at least four different times within the Mecysmaucheniidae family, a process referred to as convergent evolution.
"This research shows how little we know about spiders and how much there is still to discover," said Wood, a spider curator at Smithsonian's National Museum of Natural History. "The high-speed predatory attacks of these spiders were previously unknown."
"Scientists who are curious about natural history discover new things because they focus on understudied organisms rather than well-known model organisms," she added. "These new findings then begin filling in a puzzle, revealing epic stories about evolution across the tree of life."
After investigating trap-jaw spiders in Chile and noticing their unusual "head" anatomy, Wood used a high-speed camera to record the spiders and get a closer look at their ultra-fast strikes. Some of the species were so fast that they had to be recorded at up to 40,000 frames a second.
The videos reveal that when target prey approach the spiders at a close enough distance, the spiders snap their chelicerae with an amazing degree of power and speed, a predatory behavior that has been observed in a group of related ants but never in arachnids.
Wood was able to capture 14 species on high-speed video, and the fastest was able to snap its jaws shut in just 0.12 milliseconds, 100 times quicker than the slowest species. In addition, she noticed that jaw snapping speed was inversely correlated to spider size.
The unique trap-jaw spiders not only shed light on spiders and their evolution, they might also help scientists solve mysteries in fields that extend beyond natural history science.
"Many of our greatest innovations take their inspiration from nature," Wood said. "Studying these spiders may give us clues that allow us to design tools or robots that move in novel ways."
The findings were published in the April 7 issue of Current Biology.
