Clown fish gills

[Chooki11]

Hi, I was wondering why my clowns gills are swollen? All my water levels are fine. I noticed one with swollen gills yesterday and today the other one looks like it might be getting the same thing, the Dragon Goby in the tank looks fine and is doing it's thing. The Anemone (that the clowns don't even know exist) looks fine and all the coral seem to be doing fine as well. I Haven't seen to much of my fire shrimp lately (think it's molting though, seeing bits and pieces of it's shell everywhere) see him hiding under rocks, but is still moving. The clowns seem fine other then that though, they are sticking to their corner and eating the shrimp I put in for them, and the pellet food i some times throw in there for them. I just did a water change a week ago of 10%. I will continue to watch them, but am worried for the little guys!
Thanks for all and any help!!