Study
Bioprospecting finds the toughest biological material: extraordinary silk from a giant riverine orb spider
Agnarsson, Ingi; Kuntner, Matjaž; Blackledge, Todd A.
PLoS ONE, 2010
Dragline silk from the Darwin’s bark spider, which builds orb webs spanning rivers, was collected and mechanically tested, then compared with silk from other spiders and with synthetic fibres.
- Studied in
- Caerostris darwini
- Sample size
- silk samples tensile-tested against other spider silks
The silk was around twice as tough as any previously measured spider silk and substantially tougher than commercial synthetic fibres, with webs spanning distances of up to 25 metres.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
This species produces the toughest biological material yet measured, associated with an unusual web-building ecology.
How NatureHQ reads it
Toughness is not strength, and conflating them is the source of most confusion about spider silk. Strength is the force a fibre withstands before breaking; toughness is the total energy it absorbs first — which is what matters for a web whose job is stopping a flying insect without snapping. On toughness, this silk beats everything, biological or manufactured.
- One species with an unusual ecology; not representative of spiders generally.
- Mechanical testing of biological fibres is sensitive to humidity and to how samples are drawn.
- Toughness and tensile strength are different properties and are often conflated in coverage.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Public Library of SciencePublished in a PLOS journal under CC BY 4.0.
doi.org/10.1371/journal.pone.0011234
This reference was resolved automatically against Crossref and OpenAlex on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-09.