I just bought three danios from the store and I noticed that one of them has a white discoloration. I'm not sure whether it'a fungus, or a bacterial infection, or just some kind of harmless spot. I've put the danio in a makeshift quarantine tank. The quarried fish doesn't seem to be exhibiting any behavioral problems. I'm not really sure what to do. The other two danios are in the aquarium because they seem to be fine. Here's a picture.
