Well my experience has been NO. I had a clown fish,"Jacko", untill I intraduced a 3" Humma "Tank" Well needless to say, "Jacko" didn't make it thru the night. Woke up, couldn't find him. Asked my wife if she saw him,nope. Not a fin or anything. "Jacko" was gone without a trace. Next day,night, "tank" starts chasing my Yellow Tang. He suvived, but needless to say, "Tank" went back to lfs & we brought back a smaller Huma "Hummi, aka ZoomZoom", who is doing just fine, although he is the king of the tank, & does whatever he wants.