All fish / Poeciliidae

Northern Mountain Swordtail

Xiphophorus nezahualcoyotl

Also known as mountain swordtail, nezahualcoyotl swordtail, nezahualcoyotl, x. nezahualcoyotl

This small wild swordtail from Mexican mountain streams has an olive to silver body with a dark zigzag line along the flank and rows of small spots. Males grow a short, often dark-edged sword. Hobbyists keep it for its natural look and to help conserve pure wild-type livebearer lines.

Care at a glance

Care level

Moderate

Temperament

Peaceful

Adult size

5 cm

Temperature

18 to 25 °C

pH

7 to 8

Smallest tank

80 litres

Keep as

Group of 5 or more with more females than males

Diet

Omnivore: quality flakes, small pellets, algae and vegetable foods, live or frozen bloodworm, daphnia and brine shrimp

Swims

Middle of the tank

Lifespan

2 to 4 years

Water

Freshwater

Wild range

Mexico: upper Río Pánuco basin (Río Tamesí and Río Moctezuma drainages), Tamaulipas, San Luis Potosí and Querétaro

Breeding

It is a livebearer: females give birth to small batches of fully formed fry about every four weeks. Breeding is easy in a well-planted tank, and since adults may eat the young, dense cover or a separate rearing tank helps.

Good to know

It prefers cooler, well-oxygenated water with some current and does poorly when kept warm for long periods. Do not keep it with other swordtails or platies, as it hybridises readily.