The bane of my reefing existence. Been pulling this many or more out almost nightly for more then the past week. The white/tan ones I can deal with but the little blue/grey F's I find wrapped around Z's & P's. Not the cheap ones either. So far I've lost all my soul snatchers, and clementines, and space monsters are about half of the original colonies. I ended up moving a bunch of my high end collection to a friends tank till I can figure this out.
harelequin shrimps. problem solved.