Cærostris darwini, special guest on 1st of January 2011

The Darwin bark* spider, Araneidæ: Cærostris darwini, was recently discovered
in Madagascar by two enthomologists of the Smithsonian
National Museum of Natural History - Washington.

Females can cast giant and very strong webs across
streams, creeks and lakes, suspending the orb directly
above the water on anchor threads that can span up
to 25 m.

[Photo by Matjaz Kuntner]

With such a huge hunting ground, these spiders are never lacking for food.

[Photo by Ingi Agnarsson]

Like other orbweaver spiders, Caerostris displays extreme sexual size dimorphism
with large females and small males, which is manifested
in enigmatic sexual behaviors such as mate guarding,
male-male aggressiveness, genital mutilation, mate
plugging, and self castration.
The two enthomologists also pointed out the biology and
web architecture of the new riverine Cærostris species
due to it combining extraordinary web architecture with
exceptional silk mechanical properties [TechNews].

*[their name stems from the habits of at least some species to mimic dead bark, twigs or thorns].
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Click on > Journal of Arachnology to read more.