Something is eating my coral!

[iseeweed]

A couple of weeks ago I started noticing a white blotch at the base of this red acropora. The blotch started getting bigger, and bigger. I then noticed the same pattern on a green acropora.
Last night after all the lights were off, I shined a flashlight on the corals. I noticed some little critter, kind of looked like a tiny crab or something. The little bug was almost clear in color. It was real small and I'm almost sure it was eating the coral. I only saw it for a second, then it ran under the rock the coral was mounted on.
Any ideas?? I'm afraid I may have somting nasty.

 

[iseeweed]

Ok, It has been a week since I posted these pics. About a week ago, I removed the green acro and dipped it in an Iodine based dip. The dip didn't seem to have an effect, and the blotches have since doubled in size.
Tonight I noticed these tiny little white mite looking things swarming all over the dead parts of the coral. I'm not sure if they are causing the damage, or just eating the dead tissue.
Any ideas?? I may frag out a healthy piece and get rid of the rest.

 

[Ben1]

Maybe what you are seeing are typical pods, and the blotching is STN from the base up. Have you checked all your parameters recently with good kits. Sometimes a shift in parameters can start this type of effect.

If its not stopping the two things that have worked for me are fragging and covering the effected area with superglue or epoxy.