In the case of a clown you have consider his mouth size. Mine will take krill and squid but normally can't get it in to eat. All my clowns like formula 1 & 2 diced up, blackworms, live and frozen brine, frozen mysis shrimp, and flakes. The gold stripe I had was meek for a clown and lived behind a rock most of the time. A few weeks ago my King Angel did it in, which surprised me altho I knew they can be aggressive I was surprised when I found the clown dead and chewed up pretty good. Since they had been together for quite a while ( and the other fish could not have done what was done, I know it was the King).