Injured From Fighting Or Burned On The Heater?

[Ellieabbott4]

this is a picture of my male gourami and i have noticed that it has a raised lump and a strange red/black mark on its side. im not sure if it has been fighting with my other male gourami or if it has burned itself on the heater. the picture below the other one is what it looks like the next day. its not as red and it looks like it might be starting to heal. has anyone got any ideas of what it might be or how i can help it to heal quicker?

 

[techen]

Burns tend to be yellowish like puss stuff. It's possible it could have be fighting with the other male, You ever seen them fight before or do they tend to get on.

 

[Ellieabbott4]

it has turned yellowish now (a day later). normally this fish chases the other one but they do usually get on

 

[epic154]

go get an aquarium heater cover