I kept a dwarf zebra in a 125 softy/mushie reef years ago, and had him in there with pretty small fish, even a small school of chromis and 4 perc clowns, and he never ate anybody. BUT.....I added him when he was really tiny, (2 1/2" maybe) and as he grew he was so used to prepared foods that I wonder if it even ever occurred to him that he could eat his tankmates. He was the only lion I ever had too, so I'm far from an expert....good luck!!