Platy fry and black spots

[Alexthefishguy]

My red wagon platy gave birth to 8 fry 6 weeks ago and they started getting black dots that are turning into solid black. It was with a green lantern platy and a male dalmnation Molly and black Molly. Could it be possible that the red wag platy cross breed with the Molly or what kind of fry are they?

[coralbandit]

Mollies and platy can not cross breed.
Those look like what are called Tuxedo platy.
I breed Tuxedo swordtails and the coloring is not always the same.
Sometimes I get wag tails from them.
It is common for livebearers to show colors from their genetic history.
Swordtails and platy are basically the same as they are crossbred often.
It is not uncommon for a swordtail to store milt from a male for up to 7 months.
That means a female can have several batches of fry or a birth months after the last time she was with a male...

[Alexthefishguy]

Thank you for the help. I was also wondering if there is a way to speed up the coloring and for them to grow faster and to be able to tell them males and females apart?

[coralbandit]

Males will hide from the alpha male and stay looking female as long as needed.
Change water as often as possible to remove growth inhibiting hormones the alpha male secretes.
Also if you change more water you can feed them more.
My fish eat at least 2x a day but I change water often to accommodate it.

[Alexthefishguy]

I will do more water changes. And also about how big would you say they should be to be moved to a tank with mollies and guppies and skirt tetras?

[coralbandit]

Once they are big enough to not be eaten they can go with the others.