Australian Golden Orb WeaverFemale Male Dimorphic Males Juvenile to Mature Female Moult Prey Web of Sex Egg Sac Web

The Australian Golden Orb Spider must shed its outer exoskeleton in order to grow, in a process known as moulting (sometimes spelt molting). This process is common to all spiders, especially the female where they shed their old skin in order to grow.

To allow the spider to grow the entire cuticle must be shed periodically, a process known as moulting. A new larger cuticle is first made underneath the old one, the old one splits and the spider climbs out.

Source: Spider structure, Australian Museum1
Moulting female Australian Golden Orb Weaver Spider (Trichonephila edulis), Alice Springs NT
Moulting female Australian Golden Orb Weaver Spider (Trichonephila edulis), Alice Springs NT

Young female spiders moult frequently, thought to be at least every month (subject to the availability of food). As they grow and get older, they moult less often.

The moult itself is complex, involving processes where enzymes dissolve the layer between the skin and the rest of the body, as a new skin begins to form beneath the old skin. The nerves stay connected to the spiders sensory organs on the old skin, so that the spider still has control over her legs.

Moulting female Australian Golden Orb Weaver Spider (Trichonephila edulis), Alice Springs NT
Moulting female Australian Golden Orb Weaver Spider (Trichonephila edulis), Alice Springs NT

The process of shedding an exoskeleton is called “ecdysis”. The old skin is called an “exuvia”.

The Latin word exuviae, meaning “things stripped from a body”, is found only in the plural. Exuvia is a derived singular form

Source: Ecdysis, Wikipedia2

Both male and female spiders moult, thought to be between five and twelve times before the spider reaches maturity. Some species of spiders will moult after maturity. These stages are known as instars and the number of times it occurs is subject to food availability and a favourable growing season. When the current exoskeleton is shed, they need to remain quiet to allow their new skin to harden.

Moulting female Australian Golden Orb Weaver Spider (Trichonephila edulis), Alice Springs NT
Moulting female Australian Golden Orb Weaver Spider (Trichonephila edulis), Alice Springs NT

When the skin has become completely loose the spider falls out of her old skin. These old skins are the “dead” spiders you can see hanging…

Source: The spider – Moulting, Ed Nieuwenhuys3
Moulting female Australian Golden Orb Weaver Spider (Trichonephila edulis), Alice Springs NT
Moulting female Australian Golden Orb Weaver Spider (Trichonephila edulis), Alice Springs NT

Moulting does not come without some difficulties. Sometimes a spider may lose a leg or two during the moult. These do not grow back until the next moult.


Footnote & References

  1. Spider structure, Australian Museum, https://australian.museum/learn/animals/spiders/spider-structure/
  2. Ecdysis, Wikipedia, https://en.wikipedia.org/wiki/Ecdysis
  3. The spider – Moulting, Ed Nieuwenhuys, https://ednieuw.home.xs4all.nl/Spiders/InfoNed/blood.html

Australian Golden Orb WeaverFemale Male Dimorphic Males Juvenile to Mature Female Moult Prey Web of Sex Egg Sac Web

SpidersIndex of Spider Images Spiders in Australia Araneidae — Orb Weavers Arkys Australian Huntsman Spider Barking Spider Black House Spider Carepalxis sp Celaenia sp Crab Spiders Deinopidae — Net-casting Spiders Dolomedes sp Dolophones sp Flower Spiders Hackled Orbweavers (Uloboridae) Jewel Spider Jumping Spider Long Jawed Spider (Tetragnatha sp) Lynx Spider (Oxyopes) Mangrovia albida Maratus volans Missulena occatoria (Red-headed Mouse Spider) Miturgidae Nicodamidae (Red and Black Spider) Ogre-faced Net-casting Spider Poltys sp (Twig Spider) Redback Spider Scorpion-tailed Spider (Arachnura higginsi) Thomisidae Tiger Spider (Trichonephila plumipes) White-spotted Swift Spider (Nyssus albopunctatus) Wolf Spider