Shrinking Wrasse

[prostaff]

I inherited a pufferfish probably a toby from a friend about 2 years ago. It was placed in a 180 gal tank along with a blue ring angel, banana wrasse and maroon clown. about 6 months ago the puffer started to lose a lot of weight even though it was feeding or appeared to be feeding normally. It is still quite active but still deteriorating physically. 1 month ago my 9in banana wrasse which I have had for over 7 yrs began to siwm with mouth wide open and breathing rapidly. There is no external sign of disease and he has almost stopped eating. He is also starting to lose weight. The maroon(13yrs old) and blue ring angel(9yrs old) still appear to be okay but now I am getting worried. Do you think the puffer and wrasse are related? Will this continue to spread? Does anyone know what this might be? /How to treat?Again there are no external indicators of parasites. Any help will be appreciated