"Mushrooms" are a cousin of what we call "anemones", and that elaphant ear is just a closer cousin is all. Oh as it becomes larger it will take fish and "slowly" close up around it. ( this happens mostly at night when the little fishy decides to sleep near/on it ) Ive seen elaphant ears as big as dinner plates and they are not picky eaters when it comes swallowing a clown or your favorite tang etc. Actualy had considered it one time' they do "fill in" tanks quite nicely. But had a friend that had a real nice softie tank , had a couple of nice tangs, a purple and a yellow. One day the purple came up missing "MIA" and he was totally lost as to where it went lol.... ( no carpet diving , we checked all over ). Upon closer inspection of the tank, we noticed the elaphant ear was quite "bulgy" looking , lmao !. Quite the expensive dinner ' a 25.00 elaphant ear consumed a perfect 130.00 purple tang.