My theory has always been that juvenile fish are much more opportunistic feeders... it's a rough life on a coral reef, especially for small juvenile fish, and they need to take what they could get food wise... larger individuals will often rule the roost and could be much more specific about their diets and get set in their ways... humans are not that different... we have a guy I work with that grew up in the midwest on almost exclusively meat and potatoes... that is basically all he'll eat. I grew up having been exposed to many different foods and love seafood and most everything for instance... most people that do not like seafood, for instance, were usually not exposed to it at a young age... while those that do like seafood were... similarly, a butterfly that grows up with an abundance of *insert Acropora species* will be very unlikely to change their ways later in life in captivity... one that is exposed to other foods very early on in life will adapt to other foods (like us humans!)... I have never believed that there is some magic nutritious component that these butterflies are getting from corals, but rather a result of what I address above...
