All fish / Poeciliidae

Montezuma Swordtail

Xiphophorus montezumae

Also known as montezuma swordtail, montezuma's swordtail, montezumae swordtail, montezuma sword, モンテズマソードテール, 蒙特祖玛剑尾鱼

This wild swordtail has an olive to silvery body with a dark lateral stripe and scattered black spotting, and mature males carry a very long, slender sword that can match or exceed their body length, plus a tall dorsal fin. Hobbyists keep it as a natural, unhybridised alternative to the domestic swordtail, valued for its elegant males and lively behaviour in clear, flowing water.

Care at a glance

Care level

Moderate

Temperament

Semi

Adult size

5.5 cm

Temperature

20 to 26 °C

pH

7 to 8

Smallest tank

120 litres

Keep as

One male with several females, or a larger group with plenty of cover

Diet

Omnivore: quality flakes and granules, algae-based foods, plus live or frozen bloodworm, daphnia and brine shrimp

Swims

Middle of the tank

Lifespan

3 to 5 years

Water

Freshwater

Wild range

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

Breeding

It is a livebearer: females give birth to small broods of well-formed fry after about four weeks. Breeding is straightforward in a well-planted tank, though broods are smaller than in domestic swordtails and adults may eat the young, so dense plants or a separate rearing tank help.

Good to know

Males can be quarrelsome with each other, so give space and cover, and avoid keeping it with other Xiphophorus to prevent hybridisation and preserve pure wild lines. It is restricted in range and threatened in the wild, so source captive-bred stock.