Friday 11 November 2011

Microwhip Scorpion

Yet another arachnid that gets called a scorpion but isn't a scorpion at all! This time we're discovering one of the most overlooked and unknown of them all. You might need a magnifying glass for this one.

Microwhip Scorpions are also known as palpigrades, being 80 or so members of the order Palpigradi. There aren't so many pictures of them around but you can see some lovely ones here and here.

So let's see what we can learn about them via their names.

First, Microwhip Scorpion comes from similarities with the Whip Scorpion. Basically they both have a long thing sticking out from their rear end.

For Whip Scorpions it was long, thin and very flexible. The Microwhips are more flamboyant. They appear rigid and have bristles all along them; it looks like something you'd have next to the kitchen sink for cleaning bottles.

It would be nice to think of Microwhip Scorpions drinking beers and soft drinks and then cleaning the bottles for re-use, being all ecological and stuff. More likely they just kill creatures smaller than themselves and eat them. That's quite different.

Their prey would have to be seriously tiny since Microwhip Scorpions are already gravely minute themselves. A big one is just 3 millimetres (0.12 in) long, and most are half that or less.

A thin exoskeleton allows many of them to do all their breathing through their skin, but it also makes them prone to drying out. For this reason they live in damp places under stones or in the soil of the tropics and subtropics. Also they're scared of the light and will run away from it. All this makes it ridiculously difficult to find out anything about them.

But what does palpigrade mean?

Well, just as how Water Bears were called tardigrades because they were "slow walkers", Microwhip Scorpions are "palp walkers".

If you know about arachnids, you'll know that a lot of them use one pair of legs as antennae and 3 pairs of legs for walking. Microwhip Scorpions do this too, with their first pair of legs modified into feelers to help out in the darkness, especially since they don't have eyes anyway.

But, while scorpions have pincers at the end of long palps to aid in grappling with prey, Microwhip Scorpions have changed theirs into more legs! So it looks like they're walking with 8 legs when only 6 of them are really legs.

It seems very odd, but I guess that's the kind of thing that can happen when you have 10 limbs!


Crunchy said...

And the very best thing about this arachnid is that there might be one ON YOUR FACE AT THIS VERY MOMENT!

Joseph JG said...