Story: Spiders and other arachnids

Page 3. Mygalomorphs – tarantula relatives

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Only about 10% of New Zealand spiders are mygalomorphs, but this group includes some of the more spectacular species.

Most New Zealand mygalomorphs are large and stocky, with a body length up to 3 centimetres, and are related to tarantulas. Mygalomorphs have to strike downwards at their prey, and their fangs move up and down.

Catch a beetle

If you rest your hand on the ground, then raise the two fingers next to your thumb like a spider’s fangs, you will see how you have to lift your hand slightly.Your finger fangs can stab at the beetle that just walked by. This is how mygalomorph spiders strike at their prey.

Tunnel-web spider

The tunnel-web spider Porrhothele antipodiana (Family Hexathelidae) is found throughout New Zealand. Living among logs and loose stones, it builds silken tunnels along which it can quickly reach prey or run away from predators.

Although closely related to the very venomous Australian funnel-web Atrax robusta, tunnel-webs are harmless. However, they have big fangs and have been known to bite.

Trapdoor spider

The common trapdoor spider (Misgolas species) lives in a silken tube with a hinged trapdoor at the top. It waits with its front legs poking out from beneath the lid, and detects the vibrations of insects walking near the trapdoor. When the insect is within striking distance, the trapdoor flies open, and the spider leaps from the burrow and pulls the prey down the tube. The remains of victims are left next to the trapdoor.

New Zealand cave spider

The unique New Zealand cave spider, Spelungula cavernicola, has some features that are intermediate between mygalomorphs and araneomorphs.

Discovered in the Ōpārara caves near Karamea in 1957, it has since been found in other caves. It lives in the twilight zone near the mouth of caves rather than in full darkness, and feeds mainly on cave wētā, supplemented by blowflies.

Some cave spiders hang from the roof of caves on draglines, and feed and moult in this position. There are records of a cave spider grabbing a wētā, then letting itself down on a dragline, wrapping the prey in silk and eating it.

How to cite this page:

Simon Pollard, 'Spiders and other arachnids - Mygalomorphs – tarantula relatives', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/en/spiders-and-other-arachnids/page-3 (accessed 18 November 2017)

Story by Simon Pollard, published 24 Sep 2007