Puffer Problem?

[Adam S]

Today when i got home from school i noticed that my dogface puffer had his left gill fully open i guess and he was on the bottom of the tank but the other side was normal. I just did a water change yesterday and he seemed fine. This happened the last time i did a water change as well if i remember right. This is the second time it has happened. The only thing ive noticed different is that he is starting to turn gold where all the white is. He seems like he isnt breathing as well on that one side as the other...as in the one side is full going and this side is slow and doesnt open as much.

Any ideas on whats wrong?

 

[Adam S]

Well it seems that he is breathing fine on the ones side but the side he was gasping open in the picture, he doesnt seem to be opening his gills on that side wide or even at all. He is still eating and swimming fine soo im not sure if i should be worried.