I can’t remember which site I read this on but it stated that the secret to breeding platies and other live bearers is that there is no secret; the female platy is almost always pregnant. I’m beginning to believe that.
When I turned on the lights on my 55 gallon aquarium I noticed one of my pearl gouramis poking it’s snout up and down repeatedly into the massive growth of green cabomba at the top of the water. Upon closer examination I barely noticed movement out of the corner of my eye. When I looked under a hood there were about a dozen and a half fry cowering in the thick growth of plants. I got about eight of them into a protective plastic breeding container, the rest will have to try to survive as the previous three did.
I’m fairly certain the live breeders, i.e. the platies, were the proud parents. The pearl and opaline gouramis are bubble nest builders and I would assume that any eggs laid amongst the bubbles at the water surface equaled food for the platies, other gouramis, flame tetras and/or Siamese algae eaters. The flame tetras are egg scatterers and I guarantee if their eggs were not food for the previous fish then dozen catfish or two plecos in the tank would have taken care of them. There are a pair of ottos and the two plecos in the tank but breeding them is next to impossible. So I think it’s safe to say one of the two female platies birthed dem babies.