They don't look like much, but these tiny trap-jaw spiders found only in New Zealand and southern South America are the Beauden Barretts of the arachnid world.

While All Black Barrett is impressively quick in pursuit of the oval ball, the Mecysmaucheniidae spiders are lightning fast in pursuit of tucker.

One particular species of the Zearchaaea genus, found only in New Zealand, is so fast a researcher has struggled to record it with a high-speed camera on its highest setting.

Hannah Wood, curator of arachnids and myriapods at the Smithsonian Institute, has been studying the tiny spiders and her findings are due to appear in the scientific journal Current Biology today.


When Ms Wood first encountered a trap-jaw spider in Chile, she noticed it would sit with its jaw-like chelicerae open and ready to snap. She began recording the activity of about 100 of the spiders, which she kept in her apartment.

"High-speed video recordings showed that when a tasty insect comes close, the spiders snap their chelicerae shut with incredible power and speed. That kind of predatory behaviour had been seen before in some ants, but it was unknown in arachnids," Ms Wood said.

The video of 14 species of Mecysmaucheniid spiders revealed a range of cheliceral closing speeds, and the power output from four of the spider species exceeded the known power output of the arachnids' muscles, she said.

"The spiders' movements can't be directly powered by the spiders' tiny muscles, particularly given the short times and small distances covered during a strike. That means other structural mechanisms must allow the spiders to store energy to produce their ballistic movements.

One particular species of the Zearchaaea genus, found only in New Zealand, have such impressive jaws in pursuit of food that researchers struggled to record the act with a high-speed camera on its highest setting.

"Studying these spiders could allow humans to design robots that move in novel ways that are based on how these spiders move."

University of Canterbury School of Biological Sciences associate professor Ximena Nelson said the size of the spiders - only a few millimetres at most - may explain why their speed had not been noticed before.