Search results
Results from the WOW.Com Content Network
A classic circular form spider's web Infographic illustrating the process of constructing an orb web. A spider web, spiderweb, spider's web, or cobweb (from the archaic word coppe, meaning 'spider') [1] is a structure created by a spider out of proteinaceous spider silk extruded from its spinnerets, generally meant to catch its prey.
Spider silk structure: crystalline beta-sheets separated by amorphous linkages. Silks have a hierarchical structure. The primary structure is the amino acid sequence of its proteins (), mainly consisting of highly repetitive glycine and alanine blocks, [4] [5] which is why silks are often referred to as a block co-polymer.
By the Jurassic period, the sophisticated aerial webs of the orb-weaver spiders had already developed to take advantage of the rapidly diversifying groups of insects. A spider web preserved in amber, thought to be 110 million years old, shows evidence of a perfect "orb" web, the most famous, circular kind one thinks of when imagining spider webs.
The average toughness of the fibres is 350 MJ/m 3, and some are up to 520 MJ/m 3, making the silk twice as tough as any other spider silk known. [8] The web of Darwin's bark spider is remarkable in that it is not only the longest spanning web ever observed, but is the largest orb web ever seen, at an area of up to 2.8 square metres (30 sq ft). [2]
The silk is a complex form of protein fiber that starts off as a protein-rich liquid and then dries into solid filaments, thanks to spinnerets, an external portion of spider glands. The material ...
Generally, towards evening, the spider consumes the old web, rests for about an hour, then spins a new web in the same general location. Thus, the webs of orb-weavers are generally free of the accumulation of detritus common to other species, such as black widow spiders. Some orb-weavers do not build webs at all.
Lagonomegopidae is an extinct family of spiders known from the Cretaceous period. Members of the family are distinguished by a large pair of eyes, positioned on the anterolateral flanks of the carapace, with the rest of the eyes being small. They have generally been considered members of Palpimanoidea, but this has recently been questioned. [1]
Dragline silk is used not only to construct the outer frame and radii of the orb-shaped web but also as a hanging lifeline that allows the spider to evade and/or escape from predators. [12] The major ampullate gland that produces this silk is formed by three main sections: a central bag (B zone) flanked by a tail (A zone) and a duct heading ...