Kinda late, but....
infusoria
Take a clean gallon jar and fill it about 75 percent full of chlorine-free water. Put a few rotting lettuce leaves into the water and let it stand for a day uncovered. Then cover it and allow the jar to sit for several days. (Because the infusoria takes several days to culture, make sure you begin before the fry are born.) By that time the water should have a cloud of infusoria in it.
To feed your fish, take up some of the water with a turkey baster or eye-dropper and drip the infusoria into your fry tank. Begin with a few drops and feed several times a day. If you see your fry tank becoming cloudy, make a water change and cut back on the number of feedings. The infusoria will last for several days, long enough to allow your fry to develop to the point that they will be able to begin feeding on larger food.
After a week or so, you can begin feeding the fry live brine shrimp or microworms.