Is this a fungus or a wound i haf three Otocinclus end up in the pre filter of my Oase biomaster

[Country joe]

 

[Country joe]

Two of them have this white patch o there back, could it be a wound from ending up in the pre filter, and if you think it is do I just leave it, adding no medication.

 

[MattW68 184]

When I last kept ottos I had one develop a white mark on its tail, which I believe was caused by the fish going between the hardscape. It didn't survive even with a hospital tank and medication. I think the wound had been infected with a fungus of some kind. Does the patch look similar to this?

 

[Country joe]

Yes