I am looking into a predatory fish tank. For sure I want a lionfish and maybe a shark if they are compatible. What all can you mix with them. I heard that if the fish can't fit in its mouth it will be fine, but I wanted expert opinion. This is the list of the type of fish I want; lionfish, eel, cool starfish, shark, and a octopus would be nice but not a need. So what could my combination be?