Anyone ever have an urchin munch on their zoa's? I have had this urchin for almost a year and he has not bothered palythoa's, gsp's, or a combination yellow polyp/zoa rock. I acquired two zoa frags about two weeks ago with approximately 20 polyps each. Came home tonight and there was the urchin positioned on top of one of the frags. After I chased him off, it appears that he had munched about 75%. Besides scouring coralline, he has done a good job with algae control. After this apparent episode, I wonder if it is time to find him a new home. BTW the urchin is the typical long-spined variety (Diadema).