IME, tube anemones won't eat your fish, definitely not more than a hosting anemone will. My tube anemone sucks back down into it's tube whenever anything bigger than mysis shrimp gets near it. He certainly hasn't eaten the chromis that is currently in my tank, and after I build my sump, I'll be removing him and putting in some barnacle blennies with no fear of them being eaten. I think you're safe with putting just about any fish in the tank with your tube anemone, as long as your tank is appropriate for the fish you put in there.