I purchased three smaller Pyramid Butterflies - lovely coloration and swim habits! They school together all over the aquarium, and often are poised above the reef. They were quarantined and eating frozen food at my purchase. Healthy eaters of mixed pellets and mixed frozen....even taking Nori on occasion. They have grown, and are no longer skinny. No aggression from the many purple and yellow tangs, nor the grand sohal. They were quite timid for the 1st few weeks with diet, and one individual did not eat for a couple weeks....now all are healthy and eating prepared food.
Last month, during vacation for a week, my fish were fed with two auto feeders, but no frozen food or nori. Someone, singular or plural, ate many healthy heads of one of my 30 head ducal colonies (all started three Duncan colonies started small, grew dramatically over the past 16 months). The occasional grazing on the specific Duncan colony <several heads a day, some days no damage> continued over three more weeks after I returned home, but I never witnessed any fish giving the Duncans attention. I removed the remnant of the "consumed" colony last week, and replaced with a new frag of my Raja Rampage chalice. Two serving Duncan colonies at the present.
"Buyer beware."
I wrestled between the Pyramids and dwarf angels, lol. No fish bothers the SPS.
Finally, I have seen one Pyramid picking repeatedly on the only yellow colony of zoanthids - which is hilarious, the zoas grow like weeds, would love a fish that snacked on Zoas. The bothered zoas close up in tiny balls....new growth seems to match or exceed the butterfly diet?