In one batch of fry, there are always some who will quickly become twice as large as the others. They are the ones who come to the surface first, who are less afraid of danger and who eagerly await my visits to their tank with food in hand.
Others will end up very small. These could be females, or they could be omega fish. They tend to hide behind the plants longer, are less eager to come to the tank glass, and are far less adventuresome. They spend much of their time near the bottom of the tank.
This is normal with a batch of fish fry. However, as time passes, the smaller ones will catch up, though the females will typically remain smaller than the males. Eventually, they will all be quite accustomed to human faces and the food humans dispense.
I have begun feeding them finely crushed dry flakes in conjunction with the dried brine shrimp and First Bites. They will soon transition to the flakes and dried shrimp, and then almost exclusively to flakes, as I ready them for their new homes.