My anemone deflated today and when I looked at him there apeared to be a gray mass on the side of the tube part of him. I thought at first that it might have just been some food or something that had floated up against him. But when I squirded some water at him to move it away and clean out around his hole I found out that it is firmly attached to him. I am posting a picture of it. Could someone tell me what this might be and if i need to be worried?