I have two black angelfish in a twenty gallon, and another five marbled in a different tank. The black ones are both female and become aggressive, only when they lay eggs. I have also wanted to save the countless eggs, which they so neatly arrange on my anubias, but never successfully, as i do not own a male, to fertilize them with. With that being said, they will lay eggs regularly, those eggs being haploid, and eventually either consume them or lose them to other fish in the tank.
As far as I've read or heard, it is advised to segregate the breeding pair, turn up the temp and provide either broad-leafed plants or a piece of slate, as they prefer these smooth surfaces to lay their eggs on.
Im not sure if the male needs to be removed after fertilization takes place?