Whats happened to my pearl gourami?

Two days ago all was fine, last night when we went to feed we noticed he was hurt on top, it looks like the scales were gone so I don't know if he had been in a fight or got too close the heater or anything. Now this morning I've gone to check before I go to the shop and he really isn't looking well, is it a disease?
It's a 150L tank shared with 3 other pearls, 2 opaline and 2angelfish. We've had them for almost 4 months with no problems although recently we have had a sudden spurt of brown algae growth.

Getting closer I can see his fin on the left side is damaged too, its got bits hanging off. He's gulping alot and didn't eat, I'm not sure what's wrong or how I can help him

I don’t know enough to help. Apart from putting this back to the top of the page. Best of luck

I don't know what it is either, looks like an injury or maybe a burn or something, since it came on so suddenly. But any lost scales can also leave a fish vulnerable to secondary infections from fungus or bacteria. @NCaquatics and @essjay know gourami, hopefully they can help or know who could?

I'm not very good with illnesses, but it does look a bit like a burn. Given that he is sharing a tank with opaline gouramis and angelfish, it is possible he was being bullied and hid behind the heater.
Angels and gouramis should not really be kept in the same tank, and opalines are among the most aggressive gourami species. Even females have been known to kill every other fish in the tank. Pearl gouramis are at the less aggressive end of the behaviour spectrum.
What sex are the other pearls? If you have other males, he could be being bullied by one of them as all gouramis are territiorial fish and a dominant male will be aggressive to a subordinate male.

It could also be columnaris, and we can't get antibiotics to treat this in the UK. Stress from being bullied would allow a fish to become infected.


I'm afraid you are going to need to separate this fish from the others. If you can set up another tank or even a large plastic box with a heater and small filter, move him into that - use some media from your current filter. Add aquarium salt to the water at the rate of 1 x 15 ml spoonful per 5 gallons (20 litres) water. Do a water change every day and add salt to the new water at the same dosage to keep the salt level in the tank/container stable.
I would also separate the other pearls into a different tank as well. It is always a bad idea to keep different gourami species in the same tank. These fish would have been young when you got them and after 4 months they have matured and will be showing their true behaviour.

I think it may be columnaris or similar bacterial infection.

Separate him to a hospital tank, dose the hospital tank with aquarium salt. 1 tablespoon per 10 gallons. Change the water daily and redose the salt accordingly. Try to keep the temperature lower as bacteria spreads faster in warmer water

Thanks for your replies all! I didn't have any resources for a hospital tank but have one setting up now. We did add melafix to the tank for three days up to this morning, and today he finally ate again, and although still gulping is doing it alot less than before. It looks like he may be healing but I'm not certain.
In the tank three of the pearls are male, one did become big and would chase the others at feeding time, the two opaline always hide all the time apart from feeding or hanging out with others, they never seem aggressive. The angels only seem to go for each other, although lately they are always proper going at it, but I can't tell what sex they are.

Be very very wary of using any melafix or pimafix with labyrinth fish, the oil in those damage their delicate lung and can kill them

Oh really, thankyou for letting me know. It was all I had to hand at the time but now I'll have the hospital tank I'll be able to treat without it