Troubled Gourami

[btaylo75]

Okay, so my oldest fish is an Opaline Gourami and he has always been very active in my 55 gallon. I have only a few fish in there which leaves him with plenty of room. About a month ago the female opaline just died, literally she just died out of nowhere, she would ocasionally be agressive toward the other fish but I just came down one morning and she was gone. He has been fine for a while now but all of a sudden, his color has been taken away gradually and he is down to less than 1/3 of his body being as colorful as usual, his stomach is no longer full, he refuses to eat more than a half bite and I just don't know what to do.

I thought about giving him another female or male of the same species to try and make him active as he now avoids the other fish.

Does anyone have any suggestions or experienced anything similar to this?

 

[Tokis-Phoenix]

The gorami most likely has either an internal bacterial infection or internal parasites, does the fish have any white/stringy looking poop at all or an inflamed looking anus?
Internal bacteria can be responsable for sudden deaths in the aquarium, and both it and internal parasites will cause fish to loose weight (particularly around the stomach area, causing a sunken-looking stomach) even if they are still eating normally (although in long term cases of either parasite/desease, the fish will eventually stop eating).
Personally i would put my money on the fish having internal bacteria rather than internal parasites, but you still need to answer the above questions to make sure. Both infections are treatable, but treating the fish as early on as posible is the key to a good successful recovery.