Green Swordtail Male

Xiphophorus hellerii in its wild-type green form is the ancestral basis for all captive swordtail varieties. Males develop a prominent elongated lower caudal ray — the 'sword' — bordered in black, which is used in displays and male-male competition. The olive-green body with a faint reddish lateral stripe is the natural colouration from the river habitats of Mexico and Central America.

Green Swordtails are among the most active and energetic of all livebearers, and males are notably assertive toward each other. Only one male should be kept per group unless the tank is large enough to establish territories. Females are larger and lack the sword.

This species is ideal for anyone wanting to appreciate the natural form from which the entire swordtail aquarium trade descends.

Water: 20–26 °C, pH 7.0–8.0, moderate to hard water; active swimmers need good oxygenation. Tank: 100 L minimum; long tank preferred; plants along edges with open centre for swimming. Feeding: Omnivore; varied flake, pellets, live/frozen invertebrates, and vegetable matter. Breeding: Prolific; females produce 20–100 fry per drop; remove fry or provide dense plant cover. Compatibility: Peaceful toward other species; males may fight — keep one male or multiple females per male.