Sunday, February 25, 2018

Spider Silk Miscellany

During my searches about argiope trifasciata (banded garden) spiders for "Argiope Trifasciata Spider--Final Bug Spotting of 2017" and "Argiope Trifasciata Spider--Doggone Buggone at 2018 Start", I collected information about spider silk, webs, stabilimenta, and Charlotte's web. IMHO, the most interesting information about spider silk is specialization. Spiders produce different silk for different purposes, coming from different "extruders" called spinnerets.

Spider Silk and Webs
From "How Do Spiders Make Silk?"
The silk that spiders produce is five to six times stronger than high-grade steel by weight, and is stronger than any known natural or synthetic fiber on Earth.
From "Smooth as Silk"
All spiders produce silk but not all spiders spin webs. Silk is used for climbing, to create webs, to build smooth walls in burrows, build egg sacs, and wrap prey. … Most spiders have four or more openings, or glands, on their abdomen called spinnerets. When the spider releases the silk, it looks like one thread but it is actually many thin threads that stick together. ... Larger spiders, like the huge bird eating spiders, can actually catch and subdue animals as large as bats, mice, fish, birds and even snakes with their strong webs.
From "Spider Webs"
Web-Spinning Spiders … know when prey is trapped on their web by detecting and reacting to the vibrations the line makes from their prey moving and trying to get free.

Spiders have seven pairs of silk spinning organs or glands called “spinnerets” located either in the middle or at the end of their abdomen. Each spinneret on the spider is different from the other and used for making several kinds of silk: …

Web-Spinning spiders only use the tips of their legs when creating their webs so that their body doesn’t come in contact with the web and get stuck.
From "8 Silkily Engineered Facts About Spider Webs"
The basic structure includes radial threads that extend out like wheel spokes from the center. Another set of threads spiral out in concentric circles. The silk used to construct these two parts of the web is actually produced by different glands, which is why one is sticky and the other isn’t.
From "9 Amazing Facts about Spider Silk"
while the spider is not the only animal that can produce silk, it is the only animal that can produce different types of silk for different purposes. They can produce fine threads (called gossamer) and thicker threads, as well as both sticky and non-sticky threads.
From "Spiderweb vs. Cobweb - What You Need to know"
COMPLETE SHOW NOTES for this episode found at
Charlotte's Web
From "Charlotte's Web - WHO IS CHARLOTTE?"
Charlotte is a "barn spider." Her scientific name (today) is Araneus cavaticus. Her ability to spin orb webs is one of Charlotte’s characteristics.
From "10 Things You Might Not Know About Charlotte’s Web"
E.B. White created beloved characters out of the most unlikely of animals—a runt of a pig named Wilbur and a spider named Charlotte, who weaves words in her web to save his life.
From "Why Spiders Decorate Their Webs"
White wrote Charlotte's Web after marveling at the intricate patterns in a spider's web in the barn on his Maine farm. While we've yet to discover a real spider capable of weaving "some pig" or "terrific" in silk, we do know of many spiders that decorate their webs with zigzags, circles, and other fancy shapes and patterns.

These elaborate web decorations are known as stabilimenta. A stabilimentum (singular) may be a single zigzag line, a combination of lines, or even a spiral whorl in the web's center. A number of spiders weave stabilimenta into their webs, most notably orb weavers in the genus Argiope. Long-jawed spiders, golden silk orb weavers, and cribellate orb weavers also make web decorations.
More About Stabilimentum
"stabilimentum, stabilimenta"

In the Identification section of "stabilimentum, stabilimenta" Info tab—"conspicuous structures of heavy silk found in the webs of some orb-weavers (Araneidae)."

Recent Spider News Odds and Ends
From "Spider drinks graphene, spins web that can hold the weight of a human"
The webbing was on par with bulletproof Kevlar in strength.
From "How One of the Fastest Spinning Animals Catches Its Prey"
Flattie spiders can strike at speeds up to 3,000 degrees per second. That means that in the time it takes you to blink your eyes once, they can complete three full rotations.
From "Part spider, part scorpion creature captured in amber"
two independent teams describe four 100-million-year-old specimens encased in amber that look like a cross between a spider and a scorpion.
From "Eighteen new 'pelican' spiders discovered in Madagascan rainforest"
Pelican spiders were first discovered in the mid-1800’s, embedded in a piece of amber from the Baltics.

An ordinary house spider’s body is divided in two parts: the abdomen behind and cephalothorax in front, where the eyes sit above the mouth … But a pelican spider has an elongated head with eyes on top, and a long neck like a giraffe. The mouth sits at the base of the long neck …


Woody Lemcke said...

Thanks again Wanda! You definitely have a great talent to ferret out the most interesting stuff. It seems architects and material/civil engineers could learn a lot from spiders. I just hope they don't find a large supply of graphene and drink it on a regular basis ;^)

whilldtkwriter said...

Thx for mon mots! I bet lots of architects, engrs, and scientists study spiders. Yup, they (spiders) are indeed talented critters. BTW, the garden spider egg sac that we spotted Fri 13 of October is still strongly anchored in the photinias and seemingly still occupied.

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