I agree with robert, I have molly, platy and guppy fish, and I have never seen a molly try with anything but another molly... I recently bought 2 male sword tails, and the want even mess with my platy's... I have 1 sunset male platy, 1 red male platy, 2 male swords, male and female tuxedo platy and 2 female micky mouse platy's. I have these fish(all but the swords) for over a yr now...and only have one batch of fry and that was from my tuxedo platy...non of my platies will have any thing to do with the other.