Can anyone identify this thing? It was NOT on the fish when I got him. i looked him over really well in the bag and saw no flaws with him. I noticed this about 2 days after he was in the tank. it started off looking like some gra fuzzy thing, almost like a piece of mysis was stuck on him. now, however, it appears to be a hard object, like a shell forming or something. the fish is acting fine, it doesn't seem to bother it. the only time it does seem to bother it is when my shrimp hops on him to try and clean it off him. Fish is also eating well. thanks ahead of time for any ideas.