Why in news?
Recent research highlights advancements in understanding the Darwin's bark spider (Caerostris darwini), known for producing the toughest biological silk.
About the research
Scientists from China, Madagascar, Slovenia, and the US examined bark spiders, including C. darwini and C. kuntneri, to identify conditions for their ultra-tough silk production. Only large adult females generate this exceptional silk, which boasts a tensile strength of about 1.6 GPa—three times stronger than iron and tougher than steel—due to evolutionary pressures for massive webs over water.
About Darwin’s bark spider
Darwin’s bark spider (Caerostris darwini) is an orb-weaver spider from Madagascar, famous for spinning the largest and toughest webs in the world. Its silk is stronger than Kevlar and its webs can span rivers up to 25 meters wide.
Origin and Discovery
- Discovered: 2009 in Andasibe-Mantadia National Park, Madagascar.
- Named after: Charles Darwin, on November 24, 2009 — exactly 150 years after On the Origin of Species was published.
Web Characteristics
- Size: Largest orb webs known, ranging from 0.09 to 2.8 m² (up to 30 sq ft).
- Span: Bridge lines can stretch up to 25 meters (82 ft) across rivers and streams.
- Purpose: These massive webs allow the spider to catch flying insects over water, a niche few other spiders exploit.
Silk Properties
- Tensile strength: About 1.6 GPa, making it the toughest biological material ever studied.
- Comparison: Over 10 times tougher than Kevlar of the same size.
- Potential applications: Scientists study it for inspiration in biomaterials, engineering, and medicine.
Physical Description
- Belongs to the family Araneidae (orb-weavers).
- Has a hairy, textured body with long legs adapted for anchoring webs across wide gaps.
- Typically brown or dark-colored, blending with bark and foliage for camouflage.
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