I have a feather duster that looked like he was doing great. I understand if they get stressed, they may lose their crown and they grow back over several months.
When I put him in the tank, I put him in a crevice in some live rock. The other day, I saw the what I think is crown floating around the tank as a single unit. I could not tell if it was the crown or part of the actual worm. I think the reason why this may have happened is that one of the larger snails in my tank was on top of the casing. But since the majority of the casing is in the crevice, I could not feel down to see if it was the entire animal or not. I'm apprehensive about removing the casing because it seems to have attached to rock and I don't want to risk harming it if it is still alive.
My question is, when they lose the crown, is it usually in pieces (as if each feather separated), or is it normal for the entire thing to come off in one piece?