Deep molecular divergence in the absence of morphological and ecological change in the Californian coastal dune endemic trapdoor spider Aptostichus simus
- J. Bond, M. Hedin, M. G. Ramírez, B. Opell
- BiologyMolecular Ecology
- 1 April 2001
It is suggested that species concepts based on morphological distinctiveness, in spider groups with limited dispersal capabilities, probably underestimate true evolutionary diversity.
Revision of the genera and tropical American species of the spider family Uloboridae
- B. Opell
- Biology
- 1979
TESTING ADAPTIVE RADIATION AND KEY INNOVATION HYPOTHESES IN SPIDERS
Testing the hypothesis that adaptive radiation and key innovation have contributed to the diversity of the order Araneae shows that the inequality in diversity between the Deinopoidea and the AraneoideA is significant, and that it is associated with the replacement of primitive cribellar capture thread by viscous adhesive thread and a change from a horizontal to a vertical orb‐web orientation.
Adhesive recruitment by the viscous capture threads of araneoid orb-weaving spiders
- B. Opell, M. L. Hendricks
- EngineeringJournal of Experimental Biology
- 15 February 2007
This study tests the hypothesis that viscous thread overcomes this limitation by implementing a suspension bridge mechanism (SBM) that recruits the adhesion of multiple thread droplets, and measures the stickiness of six species' viscous threads whose profiles range from small, closely spaced droplets to large, widely spaced Droplets.
Economics of spider orb-webs: the benefits of producing adhesive capture thread and of recycling silk
- B. Opell
- Biology
- 1 August 1998
The increased economy with which adhesive capture thread achieves its stickiness may have been an important factor that favoured the origin and success of modern orb-weaving spiders that produce adhesive capture threads.
Humidity affects the extensibility of an orb-weaving spider's viscous thread droplets
- B. Opell, Shannon E. Karinshak, M. Sigler
- Environmental ScienceJournal of Experimental Biology
- 1 September 2011
It was found that the extensibility of droplets on Larinioides cornutus threads increased as humidity increased, however, the deflection of the droplets' supporting axial lines did not change, indicating that atmospheric water uptake increases glycop protein plasticity, but not glycoprotein adhesion.
The adhesive delivery system of viscous capture threads spun by orb-weaving spiders
- B. Opell, M. L. Hendricks
- Environmental ScienceJournal of Experimental Biology
- 15 September 2009
The results confirm that droplets at the edges of thread contact contribute the greatest adhesion, with each successively interior droplet contributing only 0.70 as much adhesion as a span of 20 droplets, regardless of the size and spacing of a thread's large primary droplets.
The role of granules within viscous capture threads of orb-weaving spiders
- B. Opell, M. L. Hendricks
- BiologyJournal of Experimental Biology
- 15 January 2010
It is hypothesized that granules serve to anchor larger, surrounding layers of transparent glycoprotein glue to the axial fibers of the thread, thereby equipping droplets to resist slippage on the axIAL fibers as these droplets generate adhesion, elongate under a load, and transfer force to theAxial fibers.
Changes in the mechanical properties of capture threads and the evolution of modern orb-weaving spiders
The greater extensibility of adhesive capture thread allows an orb-web to dissipate energy locally as capture threads stretch while transferring force and also enhances the web’s overall extensible, allowing it to flex and dissipate force through air resistance.
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