I put my two boys in a divided 10 gallon today. One of them, Livius, has had a white mass under his lip for a few weeks now.. and I see another growing on his cheek below his left eye, and he's starting to get white patches on his head, and starting to move down his body.

So far, I have no idea what it is.. but is it contagious? If it is, I need to know so that I can figure out if I should remove him from the tank or not, and if Felix is at risk.

He still eats, poops, and plays normally.

Here are pictures.