Attack of the Urchin (smother)

[clowny]

So i picked up a colored urchin(black white orange) and a African blue xenia (blue Cespitularia) on Sunday, Both urchin and xenia were doing great until last night, I walked past my tank and saw my urchin climbing off my xenia, well it didnt like that at all. It is now a small blob the size of penny height and diameter(was about 2 inches before incident tall and about 1/2 penny diameter) It took to the tank well when first arrived and was looking great now it still has great color but is so small and has not tried to extend at all today, and is in fact moving off of the frag plug it was purchased on. any hopes for this coral? could there be anything added to help it recover? i dosed some zooplankton today. all other corals are doing great (even tho the urching tried to go for the hammer too!)