zoos

[daniella3d]

It could be a predator or it could be a bacterial attack and the protozoas do the rest. They could disapear in one night if they are small polyps as they can melt pretty fast.

If it's a predator then other colonies will do the same, if it is a bacterial infection or some other disease than you might not have other colony doing the same.

It's not zoo....zoo is a place where animal are kept in captivity. It's either zoanthids or zoa for a shorter form.