I have one in my tank. I bought some Zoa's from LFS a few months ago, they were on what I thought was just a shell until I put it in my tank and the darn thing disappeared with my new zoa's. It has since found a new spot, but stays very close to the rocks. I haven't been feeding it, and it's doing fine. I do feed some phyto to my clams and cucumber so it likely gets some of that.