Black Dot on Platy

[theotheragentm]

One of my Platies has a black dot on her front, left fin. It doesn't seem to bother her, but it also doesn't seem to go away. I'm guessing this is some sort of hitchhiking parasite. Can someone conform this? Is there any type of cure for this? She is pregnant if it matters.

 

[Devilishturtles]

Does it look like a parasite (ie: something sticking on her) or just a discoloration? Sounds like just a discoloration to me. I can't think off the top of my head a black parasite like that.

 

[theotheragentm]

It is a yellow Platy and this dot is black or quite close to black. It's only a dot with nothing else. There is no stringiness, fuzzineses, or anything else. It's as if someone took a black marker and made a dot. I really think it's something on the fish rather than a discoloration as the fins are almost transparent towards the edges where the dot lies.