Hobbies And Interests
How Spiders Make Silk
Spider silk is made from proteins produced by glands inside the spider's abdomen. Water and proteins mix to form a bio-polymer in this low-pressure, warm environment. Different glands produce silks for different purposes. As these glands extrude the silk in liquid form, the spider's spinnerets, which are covered with tiny holes, push the liquid out, where it forms a thread. The spinnerets are located at the rear of the abdomen and are small organs that control the length of the produced silk. The dragline silk, which spiders use to raise and lower themselves, is the strongest silk any spider produces.
Types of Silk
Spiders make at least eight types of silk, only six of which are common in nature. Most spiders can produce more than one type, though few make all. Spiders use aciniform and tubuliform to create eggs and cocoons. Only orb spiders produce aggregate and flagelliform silk, which helps them make their unique web. Piniform silk helps parts of the web attach to each other, while ampullate silk makes the main body of the web.
Silk and Eggs
When a female spider lays its eggs, it uses silk to protect them. Some spiders simply adhere the eggs to their web with a small amount of silk. Other spiders form a cocoon from aciniform silk and attach it to their own bodies, carrying it until the eggs hatch. Daddy-longlegs spiders create a few cocoons at a time, but many arachnids -- such as the ladybug spider -- use only one.
Scientific Interest
Since spider silk is stronger than any other fiber, including steel, scientists are very interested in understanding the chemical processes by which spiders create it -- and ultimately learning how to synthetically replicate that process. Spiders can't be "farmed" for silk production, because they can't peacefully coexist in small enough spaces to make this profitable. A study published in the January 1996 issue of "Science" magazine details the isolation of the amino acid alanine, which may be a factor in producing the strength of the golden orb spider's silk. Pioneering research into the chemical makeup of spider silk has been done by Dr. Fritz Vollrath of Oxford University's Department of Zoology. In particular, he has developed methods for harvesting silk from spider cocoons in the wild.