Clown Goby has internal black coloration!!

[tkeracer619]

I am curious what would cause a yellow clown goby to have a black area inside him around his left gill.

Also there seems to be a black spot on the area were the left fin connects right behind his gills.

Could he have gotten stung?

I have two........... could he be a she and be getting ready to spawn?

Disease?

Fungus?

I havent added anything new in months and the system is 100% qt'd.

Params are stable and to R/C liking.


I had flatworms................. zapped them today. Could they have caused it?

Thanks in advance.