In a nut shell, as the male and female circle each other during mating she will drop an egg in the usual way of fish and quickly turn around and scoop it up into her mouth. Depending on how many she lays this can go on for a while. At the same time the male will circle keeping head to tail with the female. On his anal fin he has "eggspots" that he flutters at her. Thinking thier eggs she will try to scoop them up. At this time the male will add his milk to fertilize the eggs she is "holding" in her mouth.
For the next month or so she will hold these eggs in her mouth to protect them from predators and to insure they get a constant supply of water moving over them. When they have developed into fry she will hold them for a little while longer allowing them out for a little swim but quickly scooping them back up if danger comes near. Soon she will release them "spit" into the rocks and resume her normal life without any care as to what happens to them after that.
During the time she holds she does not eat and not too long after she spits her prodigy can become lunch.
Hth.
