sentipeed?

#1
hey guys, i havent been around for a while. But my 38 G reef is still goin. I was watching the other day and checking out one of my rocks, and i noticed some weird stuff. First, in one of the holes in the bottom of the rock, there is like a little pinkish-red centipeed or milipeed looking thing that comes out every once in a while. i have no clue what it is.. Secondly, there are like 3 or 4 little white strings coming out. Its like...there are strings coming out of the rock, and there is sand at the base of these whit tenticles, connecting them to the rock i think. Really wear. Sometimes they look bigger than other times. they can prolly streth out to about 1"-1.5" though. I just thought id ask becuase i ahve no clue what this stuff is? anybody, any ideas?