spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online August 3, 2006
Journal of Experimental Biology 209, 3131-3140 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02327
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in JEB
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Blackledge, T. A.
Right arrow Articles by Hayashi, C. Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Blackledge, T. A.
Right arrow Articles by Hayashi, C. Y.

Unraveling the mechanical properties of composite silk threads spun by cribellate orb-weaving spiders

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


Figure 1
View larger version (19K):

[in a new window]
  		Fig. 1. Exemplar force-displacement curves for cribellate capture threads. All of the curves were qualitatively similar in the extending and breaking of axial fibers followed by the gradual breaking of cribellar fibrils. All threads were initially 10 mm in length. Note that the magnitude of the x-axis for Deinopis spinosa is three times that of the other species.

 

Figure 2
View larger version (14K):

[in a new window]
  		Fig. 2. Comparison of the mechanical performance of major ampullate dragline spun by three genera of cribellate orb-weavers. Solid line, Uloborus diversus; thick broken line, Hyptiotes cavatus; thin broken line, Deinopis spinosa.

 

Figure 3
View larger version (25K):

[in a new window]
  		Fig. 3. Comparison of the biomechanical performance of the capture threads (in black) and the supporting major ampullate threads (in gray) for three genera of cribellate (deinopoid) spiders and one ecribellate (araneoid) spider. Major ampullate silk performs similarly across all four genera. In contrast, the strength, stiffness and extensibility of capture threads can vary greatly among taxa with diverse web architectures. (A) Uloborus diversus spins a complete orb web. (B) Hyptiotes cavatus spins a reduced triangle web that is held under tension by the spider. (C) Deinopis spinosa spins a specialized net that is held between the front six legs and pressed on top of prey, thereby stretching the web greatly during prey capture. (D) Argiope argentata (Fabricius 1775) spins a complete orb web but uses a capture spiral that is composed of glue-coated flagelliform fibers (see Blackledge and Hayashi, 2006Go). The capture threads in A-C exhibit behavior typical of cribellate silk where most of the stress is generated within a pair of core axial fibers that fail at high peak stresses and moderate strains. The thread then continues to strain and absorb force through the extension and failure of hundreds of surrounding fibrils until final failure. Because we could not measure the total cross-sectional area of these fibrils, stress values after failure of the axial fibers should be interpreted only as a relative indication of qualitative changes in force generated by the fibrils as the entire structure is strained.

 




© The Company of Biologists Ltd 2006