http://forum.aqua-fish.net/ A forum devoted to aquarium fish, plants, techniques and fish keeping as a whole. en http://forum.aqua-fish.net/?topic=swordtails-help-on-breeding-and-raising-fry-#1 With Swordtails they are extremly easy to breed as they are livebearers. Which means that their young are born alive not as eggs.To sex the Swordtail, the males have a gonopodium which is the anal fin modified you can normally easily tell the difference.You can tell when one of your females is about to give birth as she will fatten up become less aggresive and start forming a dark spot at the bottom of her stomach. With Livebeares much like most aquatic parents they like to eat their young. To save the fry you can always put the pregnant parent in a breeder trap which seperates most of the fry from the mother. These breeder traps are not pretty but utalitarian. If you want to save the fry and not use a ugly and annoying breeder trap which can be stressful for all the fish, you can use very protective plants such as Java moss or Cambomba. Using plants is a better option although the fry yield may not be as high at first there will not be the eventual fighting between males, when the juveniles are suddenly allowed in the tank. Eventually after about 4months or so you will find that a social structure is formed and less fry are eaten. Ackerz 2008-05-01