Spot on lens

[ToddnTN1]

Opinions on what this could be? It is deep within a Nikon 200mm Micro F/4 lens.
This is the best photograph I could get of it, but it accurately portrays what I can see when looking through the lens from the front with the aperture wide open.

 

[benhasajeep52 50]

Fungus among us. It can be cleaned at a normal lens shop. Not much you can do without removing and cleaning the lens section (rest of lens too).