What disease has my sunset gourami?

[serbanmm]

Hi all! I have a problem with my sunset gourami. I bought him1 month – 1.5 months ago and then he has not shown any sign of illness. After three or four days it appear on his skin and fins brownish-blackish patches. Since then (with 1 month ago) he doesn’t shown any changes even he’s slightly worse. However, he’s eating and swimming normally but he is a little more agitated than the other fish. I attached a picture with my fish and I hope someone to know what he has! Sorry for my English but as you noticed I’m not a native English speaker! Thanks!

PS: My aquarium: -60 litters
-heater, white light bulb, water filter
-fishes: 1 pearl gourami, 2 sunset gourami and a betta male
-5 plants
-water temperature around 82 Fahrenheit(28 Celsius)
-water parameters: 0 ammonia, 0 nitrites, 0 nitrates, PH:7.8

 

[serbanmm]

Here are more pictures....i hope to be more accurate! The fish looks brighter because of flash-light!! Fish goes now very often to the water surface to breathe!

 

[serbanmm]

My sunset gourami it's darken than ever...so, now he have the caudal fin almost black...and his other fins are also black....and of course that on the skin the patches are darker...so...someone have an ideea what it is??? In the same time he's eating and swimming like a shark...soooo...i'm so confused!

 

[chrispar0323]

It could be being abused, seems like you have some territorial fish in your tank he migh just be catching the brunt of it. Is your tank normally peacful? what number fish was he in your tank 1-4? im no expert just my opinion

 

[1077]

Do have a read here.. FAQs on Colisa lalia, C. chuna... "Dwarf" Gouramis of Many Names, Honey, Flames, Neon Blue,  Sunset Fire... Disease/Health
I am not suggesting that this could be diagnosis but rather attempting to give you more help.

 

[serbanmm]

Here are some new pics (are not so great but you can see the problem)!