Golden Silk Spider 40D0044328

Golden Silk Spider (Nephila clavipes), photographed at Hunting Island, South Carolina.

Nephila clavipes is a species of Golden Silk Spider or 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.

In the United States, it ranges throughout the coastal southeast and inland, from North Carolina to Texas. Its distribution in many regions seems localized, and it may be completely absent (or just hard to find) over wide areas. Conversely, in some arboreal or swampy nooks, adults and their webs can be found in large concentrations, especially near the coast. Golden orb-weavers are especially numerous in the time after summer and before fall in the south-eastern and southern U.S. This species is widespread - and often common - in large parts of Central America and warmer regions of South America.

The female has a long cylindrical body, up to about 50mm (2 inch) long by the end of the season. The males average 6 mm in length, and would often go unnoticed if not for the fact that they are often found in the webs of females.

The web of a mature female can reach one meter in width, the yellow threads appearing as a rich gold in sunlight. Males come into the female's web for copulating. After mating the female spins an egg sac on a tree, laying hundreds of eggs in one sac. The spider will only bite if pinched. The venom of the Golden Silk Spider is potent but not lethal to humans. It has a neurotoxic effect similar to that of the black widow spider; however, its venom is not nearly as powerful. The bite causes local pain, redness, and blisters that normally disappear within a 24-hour interval. In rare cases, it might trigger allergic reactions and result in respiratory troubles (in asthmatics) or fast-acting involuntary muscle cramps. As the genus possesses relatively strong chelicera, the bite could leave a scar on hard tissue (such as fingers).

The silk of N. clavipes has recently been used to help in mammalian neuronal regeneration. In vitro experiments showed that a single thread of silk can lead a severed neuron through the body to the site it was severed from. With a tensile strength of 4×109 N/m2, it exceeds that of steel by a factor of six. It is not recognized by the immune system and has antibacterial properties.

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