Mark on a weather loaches nose

[Banana mouse]

It's need your opinion, my weather loach has had this mark on his nose for roughly a year now, any ideas what it is?
He is still his normal gready self, chases all the fish lol.
Should I be worried about the mark on his nose thanks






I'm going to a fish shop later so i can get any treatment needed

 

[Banana mouse]

Sorry about the bad picture also does his eyes look okay?