Heyya Chris,
The males deposit a sperm packet beneath the female. When the eggs travel through the body and exit, they have to pass through the packet to get to the swimmerets. Most eggs hatch after fert, provided the male is not sterile, and teh female can hold onto the eggs long enough. IN a healthy environment, usually both present no problems, although the first time or two for the fems it is not uncommon for them to drops eggs while going the the process of learning how to carry them.
Neo eggs can be different colors, as well as mischling cards.