Can swordtails- mollies- platies breed together? For example, could a molly and a platy breed? I'm pretty sure they can, since they are closely related.
AMAZON Mollies & most other ovovivaparous livebearers- yes.
Ordinary mollies can't do it, but Amazon mollies have virtually no males of their own, but can be fertilized by most anything else so they don't need males.