Friday, May 11, 2012

Commensal Crabs RIDE that starfish!!!

Thanks to Anna and!

This is probably the first time that these swimming crabs have been observed living commensally on Luidia maculata (or possibly on ANY starfish).

When people talk about commensals (crabs or whatever) living on a larger host, its often assumed they are taking advantage of things like food (from what the sea star eats) and protection..but here's ANOTHER potential "win" for the crab-TRANSPORT (aka dispersal).  Is this possibly how these crabs get around from one place to another??

Note also how the animal keeps on arching up?  It doesn't seem to be expelling gametes (as has been documented here before) so maybe its not all too fond of the crab attention and trying to shake them off??

Ride the Luidia Express!

Wow! Have a great weekend!


Anonymous said...

This reminds me of certain urchins like Astropyga radiata and some crabs....wonder if this behavior is really advantageous?

Johnn Morales said...

Maybe the crabs are actually manipulating the starfish in order to make it elevate itself to give them space underneath as well as to make it move faster than it would otherwise clinging tightly to the substrate.

ChrisM said...

An interesting idea! I think this is one of those instances where having more time to watch and to see how it varies among hosts would really make a difference in understanding. I think its great that everyone can enjoy and learn from this video and have some input!