Nephila clavipes (Lat. clavis = key or hook; pedis = of or pertaining to a foot {genitive case of pēs}) is a species of golden orb-web spider. It lives in the warmer regions of the Americas. The large size and bright colours of the species make it distinctive. The female is much larger than the male.
As is usual among orb-weavers, there is marked sexual dimorphism in general appearance, but especially in size; in linear measurements males are three to four times smaller than females, and they also are more slenderly built. This implies a mass some thirty to seventy times smaller than that of a large female.
The specific epithet clavipes is derived from the Latin:
Because humans inadvertently transport spiders as passengers in cargo containers, plant nursery stock and the like, Nephila clavipes generally occurs very unevenly over wide areas; often there are patches of high local densities far from any other populations. Accidental human transport of the species increases markedly in late August to early September, when the spiders' reproduction is at its height.
The main web of a mature female may be as large as one meter in diameter, not counting the main filaments that anchor the web between trees; such anchor filaments may be two or three meters in length. A yellow pigment in the silk lends it a rich golden glow in suitable lighting. Males come into the female's web for copulation and mate with her while she is feeding and unable to attack them. After mating, the female spins an egg sac on a tree, laying hundreds of eggs in each sac.
The spider is not aggressive and only bites if pinched; the venom is relatively harmless and rarely causes more than slight redness and temporary localized pain.[2]
A single thread of the anchor silk has a tensile strength of 4×109N/m2, which exceeds that of steel by a factor of six.
The silk of Nephila clavipes has recently been investigated to evaluate its usefulness in surgically improving mammalianneuronal regeneration. In vitro experiments showed that a filament of the silk can lead a severed neuron through the body to the site from which it was severed. Best of all for these experiments, the silk elicits no reaction from the immune system, and thereby escapes rejection by the host body.[3]