Xiphophorus helleri
The Swordtail is perhaps the quintessential community aquarium fish. The time-tested popularity of the Swordtail can be attributed to its ease of care, peaceful temperament, and wonderfully diverse fin and color varieties. The most common Swordtail varieties include: Red Wag, Red Velvet, Marigold, Black Nubian, Pineapple, and Neon Swordtail. The male Swordtail is especially prized for its namesake feature, the showy extension on the lower part of its tail resembling a sword.
The Swordtail requires an aquarium of at least 20 gallons that is well planted with plenty of room for swimming. Because of its peaceful nature, the Swordtail is well suited for the community aquarium. However, the male Swordtail can demonstrate territorial aggression towards other male Swordtails so care should be taken when housing more than one male. Also, the Swordtail is an accomplished jumper, so be sure to provide a secure cover for the aquarium.
The Swordtail is a live-bearing fish related to freshwater aquarium favorites including guppies, mollies, and platys. As such, a female Swordtail can give birth to as many as 80 fry at one time. A spawning box is recommended, or if one is not available, provide dense floating cover to protect the Swordtail fry from potential predation by the adults. Unless it is your intention to breed Swordtails, the male Swordtail fry should be separated once the sex of the fry is determined. The Swordtail can begin breeding as young as three months of age and can quickly overpopulate an aquarium.
The Swordtail is an omnivore that will eat commercially prepared flaked foods and algae as well as freeze dried bloodworms, and brine shrimp.