Gardneri Killfish, strange marking on back.

[IanoYG]

Hello,

I have just noticed my male Gardneri Killfish has a strange mark on it's back. Is this a sign of illness, or could it maybe have been attacked? I am really not sure, it never seems to have any quarrels with other fish. Sometimes the loaches in the tank chase off other fish, that's the only fish I could think of that could do damage. It is swimming as it normally does and is eating Anyway any advice would be fantastic.

Kind regards

Ian

edit: there was supposed to be a 3rd picture, but will some reason not upload...

[IanoYG]

Managed to upload the 3rd picture on a seperate reply, sorry for that.

[kklim]

Looks like fungal infection or columnaris. One of my bettas had that two weeks ago. Treated with Waterlife Protozin and it went away.