title: Unpicking the signal thread of the sector web spider Zygiella x-notata.
abstract: Remote sensing allows an animal to extend its morphology with appropriate conductive materials and sensors providing environmental feedback from spatially removed locations. For example, the sector web spider Zygiella x-notata uses a specialized thread as both a structural bridge and signal transmitter to monitor web vibrations from its retreat at the web perimeter. To unravel this model multifunctional system, we investigated Zygiella's signal thread structure with a range of techniques, including tensile testing, laser vibrometry, electron microscopy and behavioural analysis. We found that signal threads varied significantly in the number of filaments; a result of the spider adding a lifeline each time it runs along the bridge. Our mechanical property analysis suggests that while the structure varies, its normalized load does not. We propose that the signal thread represents a complex and fully integrated multifunctional structure where filaments can be added, thus increasing absolute load-bearing capacity while maintaining signal fidelity. We conclude that such structures may serve as inspiration for remote sensing design strategies.
authors.affiliation: Department of Zoology, University of Oxford, Oxford OX1 3PS, UK beth.mortimer@zoo.ox.ac.uk.
authors.forename: Beth
authors.initials: B
authors.lastname: Mortimer
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Holland
authors.affiliation: Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow G1 1XW, UK.
authors.forename: James F C
authors.initials: JF
authors.lastname: Windmill
authors.affiliation: Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
authors.forename: Fritz
authors.initials: F
authors.lastname: Vollrath
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D013112:Spiders / Q000502:physiology*
keywords: remote sensing; silk; spider; vibration