so you just have the male betta and a swordtail? no platies? then there swordtail fry and your sword is female
Gawd knows I'm frequently mistaken, and I think that practically qualifies as my career, if only I could move into politics and get paid for it, but aren't they possibly Swordtail Platies, and sold as such, explaining the confusion?
Used to read a lot about them back in the dinosaur days when I was growing up.
Although I'd no idea (as far as I remember right now, which seems sometimes to be only about out to here) that the Swordtail Platy I'd read about and wanted as a small child, (a disastrous guppy population explosion painfully crowding out acquisitive interest in livebearers) was actually a crossbred...
http
/www.fishdeals.com/livebearers/
'... Platies and Swordtails belong to the same Genus which means they are closely related and in most cases they will interbreed quite freely. And most of the modern fancy varieties originate from various crosses between the two along with some selective breeding. ...
'It's interesting that Platies and Swordtails will often interbreed to produce hybrids. In fact most Platies and Swordtails sold as pets have genes from both species. ...'
As if life wasn't confusing enough...