Danio fish Abnormality

One of my danios appears to have something wrong with the side of his stomach. It looks translucent in a spot on one side but not the other, none of the other fish look like this. What is this and how do I treat it if needed? These are the best pictures I could get

 

From the picture looks like it could be an ulcer, which you will need an antibiotic for. Though it’s hard to tell from the picture, it looks like it could be fish lice, maybe flukes, which requires a different med

 

From the picture looks like it could be an ulcer, which you will need an antibiotic for. Though it’s hard to tell from the picture, it looks like it could be fish lice, maybe flukes, which requires a different med

I looked up ulcers, the ones i’m seeing pictures of are red. The hole on my danio is clear, could it still be an ulcer? It doesn’t look to be flukes or fish lice after I looked that up too.

 

I looked up ulcers, the ones i’m seeing pictures of are red. The hole on my danio is clear, could it still be an ulcer? It doesn’t look to be flukes or fish lice after I looked that up too.

Ulcers can sometimes be brownish. Do you know if the fish was ever injured or wounded? Ulcers usually come about as wounds that become infected.

 

Ulcers can sometimes be brownish. Do you know if the fish was ever injured or wounded? Ulcers usually come about as wounds that become infected.

No, not that I’ve ever noticed