I've got a 55 gal setup with two clowns, an assortment of snails, one hermit crab and two emerald crabs. I recently finished quarantining a small imperator angel and added him to my display tank. That was about a week ago. He seemed to be doing fine, grazing on the rocks, was not fighting with the clowns (even when going by their territory). A day ago when I turned my lights on in my tank I saw that the back of the imperator angel was nipped at and almost looked like something had feasted on its back end. It was literally chewed to its back bone. I naturally assumed that it was my clowns that got aggressive with it. I watched it throughout the day and while it stayed in hiding for most of the day, it did come out occasionally. When it was out it was near the clowns and I saw no aggression whatsoever. This morning I woke up and was looking for my angel and found him pinned down on a rock by my biggest emerald and he was just casually picking away at the backbone of my angel! I scared him away but the angel was done for. Have you guys seen this before? I was under the impression that emeralds were scavengers, not hunters.