After doing some tedious research into Corallivore Butterflies and the selectivity displayed by some certain species in choosing which coral species' they choose to prey upon, I believe it may be possible to keep some species in a reef tank as long as their preferred coral species are absent. (Of course the butterfly will have to be weaned onto an alternative diet beforehand and fed regularly...I would never have one of my fish go hungry.) I believe this is also highly depended among butterfly species though as some will prey on practically any coral while others are MUCH more selective. In the next few days I will be buying a C. bennetti butterfly to prepare to test this theory and hopefully have success to shed light upon the fact that some of these species certainly can be kept with the proper care.