Darwin’s bark spider is very small and yet constructs webs with anchor lines spanning rivers. It was discovered in 2001 in Madagascar, but a recent paper documented that its silk is stronger than Kevlar. The extra strong silk is what makes it possible for the spider to make anchor lines that are very long and can bear the weight of the central web, its contents, and the spider. Researchers counted 32 prey in a single web. These prey had not yet been wrapped up by the spider, meaning the web has a huge capacity for catching insects at any moment.
The extremely strong silk allows the Darwin’s bark spider to have a strategy no other spider can employ. It builds its webs in habitats other spiders are incapable of using, which means it can catch food without having to compete with other spiders. Their webs are built directly over streams, rivers and lakes.
In a paper titled, Bioprospecting Finds the Toughest Biological Material: Extraordinary Silk from a Giant Riverine Orb Spider researchers say they found their silk is twice as strong as any other spider’s and that it is ten times better than Kevlar. (Kevlar is used to make bulletproof jackets
and bike frames, because it is very strong and very light.)
The spiders were discovered in Madagascar’s Ranamofana National Park. Return trips in 2008 and 2010 allowed researchers to study them and their webs more closely. After conducting tests and taking measurements of the spider’s silk they concluded it is the toughest biological material known to man.
So far the scientists are not clear on how exactly the small spider constructs the anchor lines which span a stream or river and support the core web. It was reported that someone offered the explanation that the spiders create a single silk strand and then swing themselves across a stream to the bank where the fix an anchor line, and then return to the other bank and do the same, sort of like Tarzan. One of the researchers said of this idea,”We really, really tried to verify that, but it turned out to be false.” (Source: Sify.com)
By observing and understanding such materials produced by other species, the researchers hope to one day discover how humans can simulate their appealing properties in products for our own use. In their paper, the researchers noted it is likely there is even stronger spider silk yet to be discovered.
Image Credit: Lalueza-Fox, C.; Agnarsson, I.; Kuntner, M.; Blackledge, T. A.