Is there a type of crab that will eat SPS coral. I found one on one of my corals I could swear I seen him munching away on polyps. I didn't get a picture but it was a sort of flat crab like a emerald crab but the legs looked thicker and it had smaller claws. Looked hairy like a spider. I tried to catch it but it got away. Lights were near the end of the cycle. Still very bright.