I was feeding my tank today and a large piece of krill landed on my pink and purple zoanthids ... it closed up around it and began eating it (the piece of krill was larger than the polyp). I then gave a few more polyps pieces and they chomped them down as well. I always thought that zoanthids didn't really eat large food items (the others in my tank have never shown any food capture response). I imagine this will certainly support their growth.