Coral Gone Missing

[christyf5]

Hey Lee,
What is the white fuzzy stuff surrounding the base of the coral stuck in that hole?? I was just wondering because at one point I had a white fuzzy thing similar to that (yes I know the picture is waay out of focus) that was a coral eating nudibranch that in particular had a fondness for my colt which it ate most of before I finally figured out what was going on and hauled it out of there.
Just a thought

Christy