Abscess or wound on the head?

[mordor]

I haven't been at home for couple days and when I came back I noticed
that one of my apistos has something on its head. Fish seems to
behave normally but I do not know if this it an infection or wound.
Is it malachite green good for treating wounds?

 

[Neil]

Unless there is a worsening of this or you find out specifically what it is, I won't be hesitant to treat with anything. Medication can sometimes stress a fish more than the little nicks that occur on occasion. If thi turns out to be a bacterial or fungal infection, that is a different matter. How does it look now?

 

[mordor]

Its dead now. At first I only isolated it but it got weaker every day so I started treatment with metronidazole. It did not help. All other fishes are fine so I do not understand that.