Help!!!

[happyaquarium]

i have had my tank for over two years and about a year ago i noticed one of my skirted tetras had a black spot on his right fin joint... it hasn't hindered him in any way besides making this fin stick out a little further... more recently though i noticed the sam black stuff around his mouth and caudal fin... he can still eat and has not died but it prevents him from fully closing his mouth. anyone know what this is?? pics included

 

[katiekelsey]

I have some black skirt tetras and about a year ago I noticed a black spot on one of their mouths. My LFS is really said not to worry about it that sometimes this type of fish has color changes. My fish eat and they are fine. I trust this fish store as they're very knowledgeable about fish.

 

[Aquena]

I'm not sure how to help but if it is a growth that prevents him from closing his mouth and not only a mere color change, I would think it could be something wrong. If he used to be able to close his mouth and it is definitely a growth that does not sound normal to me. Good Luck! Sorry I don't have any other advice or knowledge about this.