Rapid mid-jump production of high-performance silk by jumping spiders

Jumping spiders (Salticidae) do not rely on webs to capture their prey, but they do spin a silk dragline behind them as they move through their habitat. They also spin this dragline during jumps, continuously connecting them with the surface they leapt from. Since spiders cannot spin silk in advance, this silk must be spun at the same speed as the spider jumps—in effect, requiring spin speeds over ten times faster than typical. And while many spiders can move rapidly (e.g. running or rappelling), previous research on silk has found that silk spinning rates in excess of walking and web-building speeds (~2-20mm/s) result in lower quality silk and even dragline failure. Here we found that despite being spun at high speeds (~500-700mm/s; 100-140 body lengths/s), jump-spun salticid silk showed consistent, uniform structure as well as the high-performance qualities characteristic of silk spun by other spiders, including orb-weaving species, at low speeds. Toughness of this jump-spun silk (mea...