if u start off with a small specimen, the chance of it bothering corals and clams r less imo since they havent learned to eat those things yet from the wild. i hv a coral beauty in my fowlr, and he eats my xenia. when i got the cb though, he was much bigger. all dwarf angels will nip, but as long as they dont constantly nip at the same coral or invert, then i think its fine.