Raccoon butterfly food

[Nautilus1]

I recently got a raccoon butterfly hoping he would eat aptaisia. He is only about 1.5 inches. I read that only larger ones about 3 inches will eat aptaisia. He hasnt touched any of the aptaisia so now i am worried that it will starve. What is a good food for raccons? I have added many isopods to the tank but hard to tell if he ate any of them. I have observed them in the wild and just se them picking on rocks all the time. But what are they eating? The one i have does not seem to care for any macros. I was hoping i could feed him frozen foods but am willing to catch live foods from the ocean. Any ideas on food source for a raqccon butterfly would be appreciated and will help save this little guy. Water quality is excellent.