Pygmy Swordtail
Pygmy Swordtail
Pygmy Swordtail (Xiphophorus pygmaeus) is a genuinely distinct species from the standard swordtail — not a small form of X. hellerii but a separate species endemic to the Río Axtla drainage in San Luis Potosí, Mexico. Males develop a small but distinct sword and iridescent blue or yellow coloration depending on the color form. At only 1.5 inches it is genuinely nano-sized for a swordtail.
Feeding & Care Tip: Sera Vipan Tropical Flakes and Hikari Mini Algae Wafers make excellent daily staples. Supplement 2–3× per week with Hikari Frozen or Freeze-Dried Baby Brine Shrimp, Hikari Frozen or Freeze-Dried Brine Shrimp, Hikari Frozen Daphnia, or Hikari Vibra Bites. For fry, Sera Micron Fry Food is an ideal first food. Feed small amounts 2–3 times daily.
Native to the Río Axtla and tributaries in San Luis Potosí, Mexico — clear, cool, well-oxygenated streams. A distinct species that has been recognized separately from X. hellerii since its description in 1960. The small size and iridescent coloration make it a very different fish from the standard large swordtail.
Keep in groups of at least six with more females than males. Compatible with other small, peaceful nano species — small tetras, nano rasboras, and dwarf Corydoras. Too small for standard swordtail companions. A planted nano aquarium suits this species well.
A livebearer that produces small numbers of tiny fry. Sera Micron Fry Food is essential for the tiny newborns. An unusual and collector-grade swordtail species for aquarists who appreciate the diversity of the Xiphophorus genus.
Care & Ideal Parameters
| Difficulty | Easy — Moderate |
| Temperament | Peaceful — nano community |
| Typical Adult Size | 1.5 inches (3.8 cm) |
| Min. Group Size | 6 minimum — more females than males |
| Ideal Temp | 68–79°F (20–26°C) |
| Ideal pH | 7.0–8.3 |
| Ideal GH | 8–25 dGH |
| Ideal KH | 4–15 dKH |
| Staple Food | Sera Vipan Tropical Flakes; Hikari Mini Algae Wafers |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Baby Brine Shrimp; Hikari Frozen Daphnia |
| Origin | Río Axtla drainage, San Luis Potosí, Mexico |
| Notes | Distinct species — not a small X. hellerii. Endemic to Río Axtla. Genuinely nano at 1.5 inches. Males develop small sword. Collector interest. |
