Velvet Worm – Onychophoran time travellers

There are a few certainties in Nature, but one I’m prepared to bet on is that we don’t last, in evolutionary terms, as long as the velvet worm. But they’re no worm either, nor are they insects, they’re not even an arthropod. These tiny beasts have their own phyla, the Onychophora.

Peripatellus sp. from Osborne, NZ. Photo: James Reardon

When palaeontologists first saw their ancestral forms preserved in the Cambrian rock of the Burgess Shales they weren’t even sure if they were looking at a whole organism or in what orientation they should describe it. The story is beautifully told by Stephen Jay Gould in his book Wonderful Life, a book published just before I went to University to study zoology and for me, a mind-expanding text. The truth in nature, as in life, is often stranger than fiction. About 530 million years ago the ancestors of modern-day Onychophora silently evolved into existence in what’s known as the Cambrian Explosion. Life had existed on earth for many millennia but never really more organised than algae and protozoa, but DNA is a relentless driver of invention.

A fossil of the animal Hallucigenia. Credit: Photo by Chip Clark, Smithsonian Institution.

 

These little velvet worms were there when the first animals crawled or wriggled from the water. They lurked underfoot and in the rotten timbers felled by the huge herds of Saurapod dinosaurs, they drifted into isolation as the Gondwanan supercontinent broke apart. But that was then. In light of  the grand depth of Onychophoran history it is easy to overlook their remarkable nature today. These little chaps are hunters. They stalk the mossy forests dampest corners and hunt within the rotting timbers of the forest floor. They have eyes but use highly sensitive antennae to feel their prey in the darkness. But these are no clumsy predator. When prey is found they rear back, like a snake about to strike, and squirt a glue that ensnares their prey. They wait for the glue to congeal before approaching the now immobile spider, springtail or whatever and biting a hole in it’s cuticle with two sharp  mandibles they inject an enzymatic soup to kill and liquify the internal organs of their prey which they then suck out. There is a lot more to know about these small wonders. If ever there was an animal to inspire the budding naturalist or zoologist, this must be it.

I’m currently working on filming a small sequence of this behaviour for the BBC Natural History Unit. It’s slow progress, they’re keen to keep themselves to the dark side of the log (the peripatus that is, not the BBC…) However I have started to get a few shots of a gorgeous little local species, Ooperipatellus viridimaculatus exploring it’s habitat. Just a few test shots really to get a feel for what sort of light they will tolerate and how they behave under low lighting but a great way to share the tiny majesty of the ancient velvet worm.

 

~ by motolorax on August 24, 2014.