Oct 27, 2009

Of Shear Force and Shingles

What good is a sea urchin without spines? Well, I'll tell you.

Here you've got the Indo Pacific Shingle (or Helmet) Urchin (Colobocentrotus atratus). According to Echinoblog (great site, folks), they are found in rocky intertidal areas of the South and Central Pacific. What benefit does having a helmet-shaped body serve this sea urchin? Turns out that their native waters can flow at high rates, and their shape offsets the effects of shear force.





















But the true power of this little beast is seen only when you upend one. Take a look at those tube feet (especially in the last photo). They enable the shingle urchin to withstand water flows of a couple magnitudes greater than your spiny urchine. Those spines won't do you much good if you're swept away with the current, Mr. Spiny Urchin. Nope, best to keep a low profile, like Mr. Shingle Urchin.

Thanks for the uchin, Jelo.








6 comments:

Anonymous said...

I don't find them ugly at all. I find them quite beautiful, in fact.

jenjen said...

Wow... as the spawn of a marine biologist I thought I was pretty versed in the shapes of marine invertebrates. But that's a new one on me. Super cool! I love putting new things in my brains!

ChrisM said...

Always happy to featured on Ugly Overload! Thanks for the attention guys!

Ellen said...

What beautiful colors! They look like they have reptilian skin.

Angelo said...

Hello ChrisM, big fan of your site. Good work dude.

K@ said...

These are amazing! I've never even heard of them. They've certainly evolved brilliantly, they look so alien!