I wouldn’t say that they will eat zoas as they are filter feeders but their presence may irritate especially the more sensitive and finnicky zoas. If you could remove the whole frag it would be easier to remove the spirorbid worms since you can just get a toothpick or something thin to flick off the worms. They are quite easy to remove.I have never cared too much about spirobid worms until now. There are a handful on my rasta Zoas. Some say the eat Zoas… any recommendations on removing the spirobid worms without injury the polyp base/ stem? ( not sure the technical term for this part of the Zoa)
