Thanks for all the info on plate corals. Have had mine for 8 years and am surprised it does so well in that the peppermint shrimp are a constant threat to feeding time. Once a week I give it a morsel of shrimp or scallop and have to keep watch for at least 30 minutes. The shrimps will still open the mouth of it to get the food, and honestly, I wish it would teach the shrimps a lesson but it will never happen. It extends out a good 8 inches when fully extended and has a gorgeous pink-purple mouth with the body being green neon, but changing at times. . The polyps are almost always fully extended. Have always had mine on the sand bed and it is pretty shaded by a very large spaghetti leather. Has only shifted slightly now and then. One of my favorites.