I wonder how biodegrable the spine from the long spine urchin are. I could use the Marine Epoxy to make a ball on the LR. Then stick real urchin spine on the epoxy. Is the spine alive, or dead? I can go to the LFS tomorrow, and ask him if he'll sell just the spine for half price. :-o I'll clip the spine from the urchin, and stick it on the rock.

But my foxface might have trouble with that, he sleep walk. He might end up with spine sticking out of his body in the morning.

But they will also hide in larger acro colonies as well.
All my acro colony have commensal crab inside them. Will the crab bother the babies? The bangaii is swimming close to the bottom, and all the acro colonies are on top. The father better release the babies at night.