Walking worms, who still resemble their ancestors who lived hundreds of millions of years ago, and which spit on their prey before devouring them – peripatus or velvet worms are intriguing but little-known creatures of the New Zealand undergrowth.
Full story by Paddy Ryan
Main image: Peripatus with her young
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What are peripatus?
Peripatus are like worms with legs – the name peripatus comes from the Greek ‘to walk about’. They are also called velvet worms because their many fine bristles make them look velvety.
What they look like
Peripatus look a lot like caterpillars. Their short legs have spiny pads at the tips and a hooked claw. Species in New Zealand have 13–16 pairs of legs (species overseas can have as many as 43 pairs) and grow to 35 millimetres in length (species elsewhere can grow to 22 centimetres).
New Zealand species
There are five named species of peripatus in New Zealand, with more still to be named.
Māori call peripatus ngaokeoke, from ngaoki, which means to crawl.
Fossils of the ancestors of peripatus have been found dating from around 520 million years ago. At that time, they lived mostly in the sea. They look surprisingly similar to today's peripatus.
Where they live
Peripatus dry out easily. To avoid the drying heat of the sun, they are nocturnal. They need to live in a moist place – but not one with so much water that they drown. They can be found in forest undergrowth or under rotting logs. Some have been found in tussock grassland, and one species lives beside the Tasman Glacier.
Peripatus can sense prey such as spiders or beetles with their antennae. They squirt liquid at their prey from special structures on the sides of their head. The liquid becomes sticky, trapping the victim, which the velvet worm then grabs with its jaws.
It is not certain how velvet worms reproduce. Probably, a male deposits a packet of sperm on the female’s body, which she absorbs. Once inside her body, the sperm fertilises her eggs. Some velvet worms lay eggs, which hatch. Others give birth to live young.
Most young peripatus are white, and develop colour later on.