Thursday, 1 July 2010

Some amazing facts about Velvet worms

Velvet worms

Source: Vishesh Jain, Wonders of Evolution, on

Readers please note that Vishesh Jain is a believer in evolution, and in no way does he support the opinion I express on this blog.

While spiders shoot silk, velvet worms shoot stringy goo.
Admittedly, velvet worm slime is far from silk molecularly, and spider silk departs from spinnarets on their abdomen while velvet worms use oral tubes.

Nevertheless, the slime is amazing.

Without congealing within the worm's own body, the slime is still a quick-hardening, sticky substance that sprays from two oral tubes, intertwining and lacing over its prey. This substance does not adhere to the water-repellent skin of the velvet worm, which can therefore safely approach its victim, bite a hole in its skin, and suck out its vital systems after digesting them with powerful saliva....

If you're still curious about that "weird sex," velvet worms use spermatophores, or packets of sperm, to transfer the male gametes to the female. Now this is weird enough, but there are several arthropods that do it too.

What really begs explanation is that the spermatophores are transferred from spikes on the the head of the male to the back or sides of the female. Enzymes in the female's body then break down both the spermatophore casing and the female's own skin, allowing the sperm to flow through this self-inflicted wound to her reproductive organs.

For one reason or another, the wound usually escapes infection, and velvet worms have apparently been successful enough to survive hundreds of millions of years without modification.

Velvet worms give birth in a variety of forms, ranging from oviparous(egg-laying) to ovoviviparous(egg-hatching within the body and then live-bearing) to viviparous(live-bearing). Weird.

by Vishesh Jain


  1. I just discovered your blog, and discussion of your book, through a Google search. It appears you discontinued blogging in July 2010. Are you still out there? If so, how much is the PDF of your book, in US Dollars?

    1. Llamamom

      Have just returned.

      I've put the book up on for £4.95 which translates to about $7 USD if you still want it.

      Apologies for the long absence, and I hope you get this message.