I have a problem with raising livebearers. Whenever my platies/swords have fry, I catch the majority of them and always purposely leave a few in the tank to fend on their own. I always notice the ones that I leave in the open with the adult fish grow faster and larger than the ones I raise in the breeding net.
I have a 2.5 inch long male that grew up in the tank who is only 2 months old, while I have a half-inch fry which was raised in the breeding trap who is nearly 12 months old. Same goes for ALL fry I catch and raise in the net.
What am I doing wrong? My month old batch is already doing the same. The fry I left out in the tank are already big enough to eat from the surface without hiding from the adults while the ones in the net are quite small.
I feed the netted fish 4 to 8 times a day and I give a good mix of food. I use hardboiled egg yolk, ground up betta food, soft spirulina pellets (their staple), ground up hikari veggie flakes, and a few others. The fish in the net get much more attention and variety than the adults do. Most of my net-raised fry only grow to a very max of 1.5 inches. I have a giant of a female who is nearly 4 inches long as well, but it was not raised in the net. My friend said it could be due to a lack of oxygen flow for the fry.