Swordtails are an all around great fish to keep. They are easy to care for, can handle a range of parameters, easily breed and available in many colors. They are a peaceful fish that will do well in a community tank, however it is recommended to only keep one male per tank as they tend to fight. They require at least 20 gallons as they are active swimmers. Swordtails can tolerate cooler temperatures than many tropical fish, but do best in a warm tank with a ph neutral and above and a medium hardness. As with all live bearers they breed easily and frequently and can give birth to as many as 80 fry every 28 days or so. Many times females will already be pregnant when purchased from the pet store. You can see the gravid spot below their belly, which is actually the eggs forming.