One of my Zebra Danios seems to have gotten injured. He's missing about 2/3 of his bottom lip, from left to right, with a large flap of meaty lip hanging off of one side. So much is missing he is unable to close his mouth. The other Danios in the tank seem to have noticed and have started picking on him. He looks unable to eat so far, though the injury happened sometime today. Is this something that the fish may recover from, I really don't want him in there if he'll be dying or spreading disease. I don't have a hospital tank to put him in.