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Velvet worms/peripatus/ngaokeoke

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Ruth
1237806.  Mon May 22, 2017 12:07 pm Reply with quote

Peripatus or velvet worms, adapted from http://www.teara.govt.nz/en/peripatus

Peripatus look like velvety worms with legs. The name peripatus comes from the Greek ‘to walk about’. New Zealand Māori call peripatus ngaokeoke, from ngaoki, which means to crawl. Peripatus is just one genus of velvet worm, but the name is loosely used to include the entire velvet worm phylum or subphylum, Onychophora ('claw-bearers').

The earliest fossil remains of Onychophorans date from the early Cambrian period, around 520 million years ago, and are all marine species. Onychophorans were once seen as the missing link between annelids (segmented worms) and arthropods (insects, spiders, crustacea). Like the annelids, they have a hydrostatic ‘skeleton’ – a fluid-filled core surrounded by muscle – instead of a hard exoskeleton like arthropods or a bony skeleton like vertebrates. But like the arthropods, they have chitin (a tough compound, from which their claws are formed), and a tracheal system – a series of tubes that carry oxygen into the body.
Today, the Onychophora are usually placed in the arthropod line of evolution, either as a phylum in their own right or a subphylum in the Arthropoda.

Velvet worms feed on invertebrates, are virtually blind and primarily active at night. They detect prey with their antennae, and squirt it with a gooey fluid from glands called oral papillae on each side of the head. The twin streams trap the victim in glue. The velvet worm then tears the creature open with its jaws and injects saliva, which contains digestive enzymes. It can then suck out the partially digested innards at its leisure.
New Zealand peripatus can accurately hit prey at a range of several centimetres. They may spit further than this when defending themselves from predators. Some overseas species can spit up to 50 centimetres.

The female can have 16 embryos at different stages of development in her two uteri and some species give birth to live young. Check out the link above or do a google search of 'baby velvet worm' to see how adorable they are.

 

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