Sheepshead swordtail

Xiphophorus birchmanni

Also known as Birchmann's swordtail, Swordless swordtail

FreshwaterFish

Sheepshead swordtail (Xiphophorus birchmanni) — Dnoerholm · CC BY-SA 4.0

Care at a glance

Temperature: 68–81°F (20–27°C)
pH: 7.2–8.2
Adult size: 2.8 in (7 cm)
Minimum tank: 24 gal (90 L)
Temperament: Mostly peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Medium
Breeding: Medium
Rarity: Rare
Origin: Native to the Rio Panuco basin in Hidalgo, Mexico, in fast flowing, well oxygenated streams.
Family: Poeciliidae

Overview

Keep a group in a longer tank of 90 liters or larger at 20 to 27 C, pH 7.2 to 8.2, in medium hard to hard water with brisk flow. Feed a varied diet with plenty of vegetable matter plus frozen daphnia, brine shrimp, and bloodworm. Keep several females per male, and give current and cooler temperatures rather than warm, still water. Mostly peaceful but active.

In the wild

A wild swordtail from fast mountain streams, so it wants cooler, well oxygenated water with real flow. Despite the name, males grow no sword and instead have a tall dorsal fin and a blunt, high headed profile. Both sexes are silvery with dark vertical bars. Give them a longer tank with current and open swimming room.

Good to know

Xiphophorus birchmanni is a swordless swordtail, reaching about 7 cm, whose males attract females with a large dorsal fin and body barring rather than a sword. In the wild it hybridizes with the related Xiphophorus malinche where their streams meet, and these natural hybrid zones are heavily studied by geneticists. Females give birth to 20 to 40 live young.

Did you know

Female sheepshead swordtails can be swayed by the scent of related species, which is one reason natural hybrids with Xiphophorus malinche form in the wild.