Tuesday, August 12, 2014

5 Cool, Weird Brittle Star Behavior Captured on video/pictures!

Ophiuroids (aka serpent stars and brittle stars) do some pretty remarkable things, BUT They are often tiny and cryptic so we don't get to see the cool array of things they do.

Flickr and YouTube have provided us with a HUGE quantity of imagery of interesting aspects of ophiuroid biology. Here is a sampling of the ones I found worth sharing!

1. Swollen Disk! This is the deep-sea serpent star Asteronyx! which live with arms wrapped around deep-sea cnidarians, such as sea pens. But this one has a fully inflated disk! When we study them in the lab, these are deflated and flattened. What do they do with them when inflated?  Why? 

This one is probably a different species, but it gives you an idea of how these live...with their arms wrapped around a cnidarian called a sea pen..

2. Brittle Star Burrowing!?  See those two brittle star arms emerging from the burrow?? That means the disk is buried within the sediment. But WOW! Look at the sediment being dumped out of that burrow in a continuous string! Maybe something else is in there putting that out? or is the brittle star doing that??

One of the rays of an amphiurid. Note the tube feet/spines fully occupied by sediment as it digs its way into the bottom.

That arm is probably part of this critter.. an amphiurid brittle star

3. Brittle Stars Feeding: Tube feet in ACTION!! How often do you get to see a brittle star in full feeding action??

and even MORE ophiuroid feeding action!!!

4. Brooding Brittle Star CT SCAN! Here is an internal CT scan of a BROODING ophiuroid! The ones inside the disk are juveniles!

5. Brittle Star "SWIMS"! This looks like Ophiocnemis, the brittle star which seems to find itself hitching a ride in jellyfishes! I've written about these here! 


Sarah said...

They are very cool! The swollen disk was bizarre but the CT scan was my favourite though it's also a bit creepy!

Cecily said...

That CT is amazing and Yeah those babies are a little creepy. So are they loose/planktonic as larvae and then crawl inside the brooding parent, or do they do the whole larval thing inside? How do they get out??

ChrisM said...

they live inside the brooding parent and then "escape" via the gonioducts present on the underside.. I'll have to write up a thing about that sometime...