What The Hell Is That?
 

Sorry I don't have picture of this but maybe someone will know what I'm talking about. I was looking at my live rock today and noticed something moving around on it. I looked closer and saw several tiny creatures crawling around, picking on algae and running in and out of the holes. They are almost transparent with what looks like a dark stripe down their backs. I would guess that they are some kind of shrimp. Has anyone ever seen these things before?

sounds like Copepods to me.

here is a link with a bit of information on them

http://www.reefkeeping.com/issues/2002-10/rs/index.php


Cheers,
Matt

Or do a search on Amphipods

I did a bit of reading and copepods are what they are.