Invertebrates - Centipedes

Centipedes don't actually have 100 legs and millipedes don't have 1,000 legs but they are technically referred to as 'myriapods' which means that they have 'many pairs of legs'. The two are easily recognised as the centipede has a single pair of legs per segment of its body. Millipedes have two pairs of legs per segment.

As with other sorts of invertebrates in the Wet Tropics region (especially those which live in leaf litter or soil), information on how many species are found here is not always available. The types of myriapods described below are found in the rainforests of this region but exact numbers of species of each type are not available . . . yet. Perhaps when more research is undertaken, we will have a better idea of how well represented locally the arthropods are. In the meantime, some general information is provided here.

Some of the biggest centipedes in Australia reach up to 15 cm (6 inches) long and these could give you an unpleasant bite. These scholopendrid centipedes have a mild toxin in the claws underneath the head and this toxin is used to restrain their food (mostly invertebrates) but it is not usually serious to humans. Scholopendrid centipedes can be found under rocks or tree bark with the smaller species occupying leaf litter or soil. Some species have reddish legs, making them easier to identify - that is, if you can look at it long enough. Once discovered in their hiding places, they make fast work of finding somewhere else to hide.

Much smaller and harmless are the Earth centipedes which are very slender and much longer than their larger counterparts above. This appear to be incapable of consuming solid food particles and so restrict their diet to soft bodied invertebrates such as earthworms, molluscs and some insects. These are found in wetter habitats under moist bark and in soil but some range into semi-arid areas.

Another centipede which may be useful around the house - especially for those who dislike spiders - is the House Centipede. Rather different to the large centipedes found under rocks, this creature is small with very long legs and even longer antennae and final pair of legs. They can be seen occasionally scurrying from closets or other hiding places and they will happily eat any spiders and other insects they find.

The millipedes are usually easy to distinguish from the centipedes because of their double-paired legs per body segment but this appears to be mostly an adult characteristic. Apparently, many species have single pairs of legs in their juvenile stages (instars). The millipedes do not have the toxin of the predatory centipedes and most of them feed on plant material, algae or decomposing vegetation.

There are several types of millipedes but perhaps the easiest to recognise is the Pill millipede.

This is a short, stout millipede reaching up to 3 or 4 cm (1.2 to 1.6 inches) which has very hard and shiny segments (these are called schlerotized tergites). Like your average garden slater (or woodlouse), the Pill millipede rolls up into a ball when disturbed, protecting its head and legs.