Northern mountain swordtail

Xiphophorus nezahualcoyotl

A deep-bodied male with a prominent dorsal; spots are variable.

This spotted adult male has a silver-green body and yellowish black-edged sword. Unspotted fish occur, and younger males may have little sword development.

Adult length: Up to 5 cm
Water temperature: 20–23.3 °C

Native range: Central America: Rio Tamasi drainage in San Luis Potosi, Mexico.

Natural habitat: Inhabits fast-flowing mountain creeks.

Largest wild male 48 mm SL, excluding fins. Keep at 68–74°F.

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Appearance and identification

Differs from the red-striped alvarezi in body depth, spotting and dorsal prominence.

Same-species behaviour

Males pursue females; provide retreats.

Diet and feeding

Accepts flakes and pellets of 1 mm or less.

Compatibility limits

Small size does not prevent pursuit. Keep water clean and avoid prolonged acidic conditions.

Aquarium environment

Fry are actively preyed on; floating cover alone is inadequate.

Sources