Topic: Spider FAQs
Is part of topic Spiders of New Zealand
What do I do if I want to get a spider identified?
You can try and identify it yourself using our What Spider Is That? section. If that doesn’t help, you can contact Te Papa's experts using the enquiry form. If you would like to send your spider in for identification, please see the Expertise section on our Insects, Spiders, and Similar page.
How many kinds of spider are there?
Worldwide, about 35,000 to 40,000 species of spider are known to scientists. In New Zealand, around 1100 species have been discovered with 95 per cent of them found nowhere else on earth. However, this may only be the tip of the iceberg as scientists estimate there are somewhere between 2500 and 3500 species in New Zealand.
Why doesn't a spider get caught in its own web?
Spiders are thought to produce a special liquid that they coat their bodies with. This stops them getting caught in the sticky part of the web.
What is the difference between a spider and an insect?
Many people mistakenly group spiders with insects. While spiders and insects are both arthropods (animals with an exoskeleton) and have a lot in common, there are some important differences that separate them.
Spiders are actually arachnids, a group that includes mites, ticks, scorpions, and harvestmen, among others. The most obvious feature that distinguishes arachnids from insects is the number of legs. Arachnids have eight, while insects only have six.
Unlike insects, spiders don't have antennae (feelers). The main part of the spider's body is also different from an insect's - while an insect has a head, thorax, and abdomen, the spider has the head and thorax fused into one structure called a cephalothorax.
What is ballooning?
This is one method that the young of some species such as katipo and nursery web spiders use to colonise new areas. The spiderling will climb to a point (such as the end of a branch) where it is exposed to air currents. It will then produce a small quantity of silk called gossamer.
The wind catches the gossamer and carries it aloft, taking the spiderling with it. If conditions are right, the spider may not land for hundreds of kilometres, although a journey of only a few kilometres would be more usual.
How do spiders grow?
A spider starts its life as one of a number of fertilised eggs, bound together in a protective silken egg sac. After a few weeks, the spiderling is ready to hatch out.
Usually, the spider does not need to feed straight away as it can survive on yolk reserves from the egg. Spiders do not stay like this forever, but they face a major problem if they are to grow bigger. They have an exoskeleton, as do other arthropods such as insects and crustaceans.
Exoskeleton literally means ‘skeleton on the outside’. With the exception of the abdomen, a spider’s exoskeleton is quite rigid and can’t stretch, preventing the spider from growing. However, spiders and other arthropods get around this problem by moulting.
This process starts with the growth of a new exoskeleton underneath the old one. When the spider is ready to moult, the old exoskeleton splits and gradually the spider pulls itself free.
At this point, the new exoskeleton is still soft and wrinkled. It will be stretched and smoothed before it hardens at its new, larger size. The spider is unable to defend itself until the new exoskeleton dries out.
A spider has to undergo several moults through the course of its life. How many moults usually depends on how large it will grow. Very small spiders usually need fewer moults to reach adulthood than larger spiders such as tarantulas.
Males also tend to be smaller than females, and therefore, usually undergo fewer moults. Males and females generally can’t be distinguished from one another until they have reached their final moult. It is only then that the reproductive structures which allow them to be told apart become obvious.