My Fu Manchu does well, he bumps the shrimp but doesn't eat them. He eats tiny clownfish i give him. I know a a guy that breeds them and i get the rejects or the dead ones, he freezes them for me
As long as it fits in it's mouth its fair game it is a predator. He is 4 years olds so i am doing something right, although my 2 year old bubble tip just croaked...bloody weird that was.