My white molly (Captain Jack) lately hasn't been looking well. He's in the 10 gallon and his right eye is about twice the size of his other eye. Also, some of his scales are lifting up, which I know is't a good sign. He's also got some white spots on his tail fin, like little dots. But not solid, like ich. It's more like centralized milky areas in his slime coat. He's in the same tank with my angelfish and ghost shrimp, and the black molly is in a breeder tank ready to give birth. The other fish are perfectly healthy. I thought maybe he's just too old. I don't want the white molly to spread any harmful diseases to the other fish, so what do you guys think I should do? Euthanization? 
