It's on the glass, not in the water. He's not breathing heavy, and since he had daphnia for breakfast the little scavenger has been spending a lot of time hunting around on the bottom, so there doesn't appear to be any breathing issues.
There is the plastic plant that he ripped his caudal fin on- maybe he scraped his underside as well. Now that I think of it, the day I noticed his beard I had also exercised him by holding up a mirror and getting him to flare, not for very long, though, a few seconds maybe. Possibly it was this?
In case you're wondering, the tank ammonia is between 0 and.25 (the tank is not cycled yet and there is ammonia in my tap water- I've been detoxing with Prime in the meantime), nitrites 0 and nitrates 20.