Black dots

[Erink]

Hey everyone,

One of my hammerheads has a black dot on it and the other has black on the tip. They both are happy. Any clue what this is?
The bottom 2 pix are the same one, just different angle. Best I can get...

 

[Ron Reefman]

I don't know what that is, but if it's not growing or propagating, I wouldn't worry about it.