This spider is so fast, that if you blink you really will miss it. Now, research has revealed how this group of arachnids hold the title of the fastest spinners on land.
In order to catch their prey – which usually consists of crickets and flies – the spiders belonging to the family Selenopidae, commonly known as flatties, are able to sense the approach of insects from any direction before rapidly whirling around to pounce of the unsuspecting critters. In fact, so adept at turning around are they, these spiders can rotate fully three times in the time it takes you to blink.
Using high-speed cameras and some willing flatties, a team of researchers were able to capture on camera what is simply too fast for us to see in real time, and then slow it down to figure out precisely how the spiders manage to turn on a dime. They have published their results in the Journal of Experimental Biology.
The way that the spiders manage their high-speed spinning is to do with the way they position themselves. The arachnids use their abundances of limbs to their advantage, placing each leg facing a different direction and so covering the 360 degrees surrounding them. As sit-and-wait hunters, it means that it doesn’t matter which angle the prey then approaches at, the spider can whip around and pounce.
“We found that the leg nearest the prey anchors to the ground, creating a leverage point from which the spider can pull in its torso closer to the prey,” said Yu Zeng, co-author of the study. As the leg closest to the prey pulls on the surface, the legs furthest away push off, creating torque and allowing the creature to turn so rapidly.
But the spider is not done there and has one final trick up its sleeves. In the style of the best figure skaters, the arachnids tuck in all their other legs, holding them close to their bodies. This means that they twirl up to 40 percent faster by reducing their leggy drag, and then can stop suddenly and precisely with their jaws right next to their prey, leaving no escape for the unfortunate victims.
By understanding how these speedy spiders spin it might enable others to design better robots that can themselves turn in small confined spaces. “You just never know what path science may lead you down next – some of the best discoveries are made by accident,” explained co-author Dr Sarah Crews.
