First published online June 15, 2006
Journal of Experimental Biology 209, 2452-2461 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02275
Silken toolkits: biomechanics of silk fibers spun by the orb web spider Argiope argentata (Fabricius 1775)
Todd A. Blackledge1,* and
Cheryl Y. Hayashi2
1 Department of Biology, University of Akron, Akron, OH 44325-3908,
USA
2 Department of Biology, University of California, Riverside, CA 92521,
USA

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Fig. 1. Quasistatic mechanical properties of each type of fibrous silk spun by
Argiope argentata (mean ± s.e.m.). Standard errors were
calculated using individual spiders, rather than total numbers of fibers
tested, as the sampling unit. See Table
1 for sample sizes. ac, aciniform; cp, capture spiral; mj, major
ampullate; mn, minor ampullate; tb, tubuliform.
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Fig. 2. Typical stressstrain curves for each of the five fibrous silks spun
by Argiope argentata. Five tests are shown for each silk. Note the
difference in the magnitude of the x axis for most types of silk
(AD) relative to capture spiral silk (E).
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Fig. 3. Diameters of single fibers (mean ± s.e.m.) for each of the different
types of silks spun by Argiope argentata. Standard errors were
calculated using individual spiders, rather than total numbers of fibers
tested, as the sampling unit. See Table
1 for sample sizes. ac, aciniform; cp, capture spiral; mj, major
ampullate; mn, minor ampullate; tb, tubuliform.
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Fig. 4. Dynamic mechanical properties of each type of fibrous silk spun by
Argiope argentata (mean ± s.e.m.). For these data only, s.e.m.
was calculated using the total number of fibers tested as the sampling unit,
rather than individual spiders. Properties for capture spiral were measurable
only at high strain. See Table
2 for sample sizes. E', storage modulus; tan
, loss tangent; ac, aciniform; cp, capture spiral; mj, major ampullate;
mn, minor ampullate; tb, tubuliform.
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Fig. 5. Exemplar dynamic mechanical curves for each of the five fibrous silks spun
by Argiope argentata. Gray denotes the loss tangent (tan ) and
black denotes the storage modulus (E'). Loss tangent could not
be measure effectively for capture spiral due to the extremely low magnitude
of the loss modulus. Note the difference in the scale of the x axis
for capture spiral (E) relative to other types of silk (AD).
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Fig. 6. Scanning electron microscope image of a fiber of tubuliform silk exhibiting
characteristic grooves and nodules on its exterior. Bar, 5 µm.
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© The Company of Biologists Ltd 2006