spider shoots silk from feet

Just as Spiderman shoots strands of silk from his wrists, so can spiders spool out silk they make on their feet, a new study shows.

Normally spiders generate silk in glands (see left) in their rears, and pull the strands out with their legs.

But a superhero that did this wouldn't be very, well, charismatic.

Spiderman's creator, Stan Lee, bent the known rules of biology. His character, after having been bit by a radioactive spider, gained the ability to shoot silk from his wrists.

It turns out that at least one spider species does the same, generating silk from its legs, researchers report in the upcoming issue of the journal Nature.

The researchers coaxed the zebra tarantula (Aphonopelma seemanni, see right) into showing off its unusual skill by climbing vertical glass surfaces.

These tarantulas are much larger than the average spider, and so may need extra sticking power beyond the means spiders usually use for gripping surfaces: tiny hooks and an exotic force of molecular attraction.

Read more on National Geographic News


Silk glands electron microscope photo by Dennis Kunkel, and tarantula photo by Damian Schofield.