The Real Shelob – A Freshly Moulted Tunnelweb Spider

Our Encounter

Whilst out on bird counts in Pohangina (Manawatu, New Zealand), Emma and I stumbled across a dead tree which was still standing. Being curious ecologists, we peeled back a large piece of bark. Behind the bark was this wonderful tunnelweb spider.

Click to zoom in

It had just moulted, displaying its cream cephalothorax (fused head and thorax) and blue translucent legs. Normally, these spiders are entirely black or black with a red/orange cephalothorax. This spider, given time, would slowly change to this darker colouration as its exoskeleton hardened.

Click to zoom in

---

Tunnelweb Facts

• Our spider is a tunnelweb spider, most likely a black tunnelweb (Porrhothele spp.)
• The black tunnelweb spider (Porrhothele antipodiana) New Zealand’s heaviest spider
• Peter Jackson described this spider as the inspiration for Shelob in the Lord of the Rings

  Click to zoom in
  

• They are a large species of spider reaching 5cm in length including their legs
• They are part of the infraorder Mygalomorphae, a primitive group of spiders including the tarantulas
• Mygalomorphs possess paraxial chelicerae (downwards moving fangs) and have a primitive respiratory system
• Tunnelweb spiders create silk tunnels beneath logs and stones
• Their spinnerets are easily visible extending from the rear of the abdomen
• Vibrations in the silk surrounding the tunnel entrance alert the spider to potential prey

Click to zoom in

• New Zealand tunnelweb spiders are closely related to Australian funnelweb spiders
• If handled inappropriately, they may give a painful bite
• Unlike their Australian cousins, however, their bite is not considered to be harmful to humans
• Their prey includes beetles, slaters and millipedes, but there are accounts of them eating snails and mice

Click to zoom in

• Male spiders face a predicament in that to find a female he must enter her tunnel
• Scientists at Canterbury University have found that not only could thing go horribly wrong for a male entering a females tunnel, but they have noted males eating females

---

Other New Zealand Tunnelweb Spiders

There are 85 species of tunnelweb spider known worldwide. Of these, 25 are found in New Zealand.

According to Crowe’s book, ‘Which New Zealand Spider?’, the most common New Zealand tunnelweb species is the banded tunnelweb (Hexathele hochstetteri) which we are yet to see. The search is on!

---

Are you a spider-lover?

Check out some of our other spider blog posts here:

---

References and Further Reading

Crowe, Andrew (2007). Which New Zealand Spider?. North Shore: Penguin. p. 29. ISBN 978-0-14-300643-5

Landcare Research Website, Black tunnelweb spider – https://www.landcareresearch.co.nz/resources/identification/animals/bug-id/what-is-this-bug/bugs-with-legs/8-legs/spiders/black-tunnelweb-spider
(Retrieved 06 April, 2018)

Naturespic Website, Image – https://www.naturespic.com/NewZealand/image.asp?id=6284
(Retrieved 06 April, 2018)

Te Papa Website, Black tunnelweb spider – https://collections.tepapa.govt.nz/topic/9426
(Retrieved 06 April, 2018)

Te Ara Website, Black tunnelweb spider – https://teara.govt.nz/en/photograph/12423/black-tunnel-web-spider
(Retrieved 06 April, 2018)