Comparative biomechanical study reveals distinct energy-dissipation strategies in two orb-weaving spiders, highlighting divergent structural solutions for kinetic energy absorption.
Key Points
To assess and compare the mechanical properties, pretension distributions, and kinetic energy absorption mechanisms of radial and spiral silk threads between two orb-weaving spider species.
Measured radial thread pretensions in Araneus diadematus webs using a rapid response microbalance.
Evaluated stress-strain relationships for dry radial and wet spiral threads of Araneus diadematus, as well as dry hackled-band spiral threads of Uloborus walckenaerius.
Araneus diadematus radial threads demonstrated an extensibility of 39.4%, a tensile strength of 1153.8 MPa, and 56% hysteresis, with greater pretension variability in the upper web half despite equal average pretensions between halves.
Araneus diadematus wet spiral threads absorbed kinetic energy through high extensibility (about 475%), resisting major force after 100–200% extension before failing suddenly.
Uloborus walckenaerius hackled bands exhibited lower extensibility (about 125%) and absorbed energy through frictional resistance generated by fine hackled fibers breaking in succession.