Use | Example | Reference |
---|---|---|
Prey capture | The orb webs produced by the Araneidae (typical orb-weavers); tube webs; tangle webs; sheet webs; lace webs, dome webs; single thread used by the Bolas spiders for 'fishing'. | [3][5] |
Prey immobilisation | Silk used as 'swathing bands' to wrap up prey. Often combined with immobilising prey using a venom. In species of Scytodes the silk is combined with venom and squirted from the chelicerae. | [3] |
Reproduction | Male spiders may produce sperm webs; spider eggs are covered in silk cocoons. | [3][6] |
Dispersal | 'Ballooning' or 'kiting' used by smaller spiders to float through the air, for instance for dispersal. | [7] |
Source of food | The kleptoparasiticArgyrodes eating the silk of host spider webs. Some daily weavers of temporary webs also eat their own unused silk daily, thus mitigating a heavy metabolic expense. | [1][8] |
Nest lining and nest construction | Tube webs used by 'primitive' spiders such as the European tube web spider (Segestria florentina). Threads radiate out of nest to provide a sensory link to the outside. Silk is a component of the lids of spiders that use 'trapdoors', such as members of the family Ctenizidae, and the 'water' or 'diving bell' spider Argyroneta aquatica builds its diving bell of silk. | [5] |
Guide lines | Some spiders that venture from shelter will leave a trail of silk by which to find their way home again. | [8] |
Drop lines and anchor lines | Many spiders, such as the Salticidae, that venture from shelter and leave a trail of silk, use that as an emergency line in case of falling from inverted or vertical surfaces. Many others, even web dwellers, will deliberately drop from a web when alarmed, using a silken thread as a drop line by which they can return in due course. Some, such as species of Paramystaria, also will hang from a drop line when feeding. | [8] |
Alarm lines | Some spiders that do not spin actual trap webs do lay out alarm webs that the feet of their prey (such as ants) can disturb, cueing the spider to rush out and secure the meal if it is small enough, or to avoid contact if the intruder seems too formidable. | [8] |
Pheromonal trails | Some wandering spiders will leave a largely continuous trail of silk impregnated with pheromones that the opposite sex can follow to find a mate. | [8] |
Gland | Silk Use |
---|---|
Ampullate (major) | Dragline silk—used for the web's outer rim and spokes, also for the lifeline and for ballooning. |
Ampullate (minor) | Used for temporary scaffolding during web construction. |
Flagelliform | Capture-spiral silk—used for the capturing lines of the web. |
Tubuliform | Egg cocoon silk—used for protective egg sacs. |
Aciniform | Used to wrap and secure freshly captured prey; used in the male sperm webs; used in stabilimenta. |
Aggregate | A silk glue of sticky globules. |
Piriform | Used to form bonds between separate threads for attachment points. |
Silk | Use |
---|---|
major-ampullate (dragline) silk | Used for the web's outer rim and spokes and also for the lifeline. Can be as strong per unit weight as steel, but much tougher. |
capture-spiral (flagelliform) silk | Used for the capturing lines of the web. Sticky, extremely stretchy and tough. The capture spiral is sticky due to droplets of aggregate (a spider glue) that is placed on the spiral. The elasticity of flagelliform allows for enough time for the aggregate to adhere to the aerial prey flying into the web. |
tubiliform (a.k.a. cylindriform) silk | Used for protective egg sacs. Stiffest silk. |
aciniform silk | Used to wrap and secure freshly captured prey. Two to three times as tough as the other silks, including dragline. |
minor-ampullate silk | Used for temporary scaffolding during web construction. |
Piriform (pyriform) | Piriform serves as the attachment disk to dragline silk. Piriform is used in attaching spider silks together to construct a stable web. |
Organism | Details | Average Maximum breaking stress (MPa) | Average Strain (%) | Reference |
---|---|---|---|---|
Darwin's bark spider (Caerostris darwini) | Malagasy spider famed for making webs with strands up to 25m long, across rivers. 'C. darwini silk is more than twice as tough as any previously described silk' | 1850 ±350 | 33 ±0.08 | [21] |
Nephila clavipes | Typical golden orb weaving spider | 710–1200 | 18–27 | [63][64] |
Bombyx mori Silkworms | Silkworms were genetically altered to express spider proteins and fibres measured.[65] | 660 | 18.5 | [66] |
E. coli | Synthesising a large and repetitive molecule (~300 kDa) is complex, but required for the best silk. Here E. coli was engineered to produce a 556 kDa protein. Fibers spun from these synthetic spidroins are the first to fully replicate the mechanical performance of natural spider silk by all common metrics. | 1030 ±110 | 18 ±6 | [67] |
Goats | Goats were genetically modified to secrete silk proteins in their milk, which could then be purified. | 285–250 | 30–40 | [68] |
Tobacco & potato plants | Tobacco and potato plants were genetically modified to produce silk proteins. Patents were granted,[69] but no fibres have yet been described in the literature. | n/a | n/a | [70] |
Area of contribution | Year | Main researchers [Ref] | Title of paper | Contribution to the field |
---|---|---|---|---|
Chemical Basis | 1960 | Fischer, F. & Brander, J.[80] | 'Eine Analyse der Gespinste der Kreuzspinne' (Amino acid composition analysis of spider silk) | |
1960 | Lucas, F. & et al.[81][82] | 'The Composition of Arthropod Silk Fibrons; Comparative studies of fibroins' | ||
Gene Sequence | 1990 | Xu, M. & Lewis, R. V.[83] | 'Structure of a Protein Superfiber − Spider Dragline Silk' | |
Mechanical Properties | 1964 | Lucas, F.[84] | 'Spiders and their silks' | First time compared mechanical properties of spider silk with other materials in a scientific paper. |
1989 | Vollrath, F. & Edmonds, D. T.[85] | 'Modulation of the Mechanical Properties of Spider Silk by Coating with Water' | First important paper suggesting the water interplay with spider silk fibroin modulating the properties of silk. | |
2001 | Vollrath, F. & Shao, Z.Z.[86] | 'The effect of spinning conditions on the mechanics of a spider's dragline silk' | ||
2006 | Plaza, G.R., Guinea, G.V., Pérez-Rigueiro, J. & Elices, M.[10] | 'Thermo-hygro-mechanical behavior of spider dragline silk: Glassy and rubbery states' | Combined effect of humidity and temperature on the mechanical properties. Glass-transition temperature dependence on humidity. | |
Structural Characterisation | 1992 | Hinman, M.B. & Lewis, R. V[26] | 'Isolation of a clone encoding a second dragline silk fibroin. Nephila clavipes dragline silk is a two-protein fiber' | |
1994 | Simmons, A. & et al.[87] | 'Solid-State C-13 Nmr of Nephila-Clavipes Dragline Silk Establishes Structure and Identity of Crystalline Regions' | First NMR study of spider silk. | |
1999 | Shao, Z., Vollrath, F. & et al.[88] | 'Analysis of spider silk in native and supercontracted states using Raman spectroscopy' | First Raman study of spider silk. | |
1999 | Riekel, C., Muller, M.& et al.[89] | 'Aspects of X-ray diffraction on single spider fibers' | First X-ray on single spider silk fibres. | |
2000 | Knight, D.P., Vollrath, F. & et al.[90] | 'Beta transition and stress-induced phase separation in the spinning of spider dragline silk' | Secondary structural transition confirmation during spinning. | |
2001 | Riekel, C. & Vollrath, F.[91] | 'Spider silk fibre extrusion: combined wide- and small-angle X- ray microdiffraction experiments' | First X-ray on spider silk dope. | |
2002 | Van Beek, J. D. & et al.[28] | 'The molecular structure of spider dragline silk: Folding and orientation of the protein backbone' | ||
Structure-Property Relationship | 1986 | Gosline, G.M. & et al.[92] | 'The structure and properties of spider silk' | First attempt to link structure with properties of spider silk |
1994 | Termonia, Y[32] | 'Molecular Modeling of Spider Silk Elasticity' | X-ray evidence presented in this paper; simple model of crystallites embedded in amorphous regions. | |
1996 | Simmons, A. & et al.[27] | 'Molecular orientation and two-component nature of the crystalline fraction of spider dragline silk' | Two types of alanine-rich crystalline regions were defined. | |
2006 | Vollrath, F. & Porter, D.[93] | 'Spider silk as an archetypal protein elastomer' | New insight and model to spider silk based on Group Interaction Modelling. | |
Native Spinning | 1991 | Kerkam, K., Kaplan, D. & et al.[94] | 'Liquid Crystallinity of Natural Silk Secretions' | |
1999 | Knight, D.P. & Vollrath, F.[95] | 'Liquid crystals and flow elongation in a spider's silk production line' | ||
2001 | Vollrath, F. & Knight, D.P.[17] | 'Liquid crystalline spinning of spider silk' | The most cited paper on spider silk | |
2005 | Guinea, G.V., Elices, M., Pérez-Rigueiro, J. & Plaza, G.R.[9] | 'Stretching of supercontracted fibers: a link between spinning and the variability of spider silk' | Explanation of the variability of mechanical properties. | |
Reconstituted /Synthetic Spider Silk and Artificial Spinning | 1995 | Prince, J. T., Kaplan, D. L. & et al.[96] | 'Construction, Cloning, and Expression of Synthetic Genes Encoding Spider Dragline Silk' | First successful synthesis of Spider silk by E. coli. |
1998 | Arcidiacono, S., Kaplan, D.L. & et al.[97] | 'Purification and characterization of recombinant spider silk expressed in Escherichia coli' | ||
1998 | Seidel, A., Jelinski, L.W. & et al.[98] | 'Artificial Spinning of Spider Silk' | First controlled wet-spinning of reconstituted spider silk. |
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