Theyre the lil pipe shaped things by the patches of coraline on both sides of the rock, theres 2 in that pic I see.
I have all kinds of these guys in my tank, I mean alot.Big fat ones to lil guys like that in the pic. I havent encountered any problems, sometimes it would disturb some polyps on my cabbage coral, but I havent see any stretched out over my sps either, though the flow around the SPS should be a lil too strong to be doing that though. I know both my yellow and sixline wrasse dont mess with them, so I wouldnt know about a "reef safe" fish that would as those are my most predatorial, oh, and my Copperband too but he doesnt mess with em either.
-Justin