Swordtail

Xiphophorus hellerii

Synonyms Green swordtail · Red swordtail · Xiphophorus helleri · Kohaku swordtail · Pineapple swordtail · Lyretail swordtail

Swordtail (Xiphophorus hellerii) is a semi-aggressive freshwater fish that reaches about 12 cm (4.7 in) and swims in open water. It wants 72–82°F (22–28°C) and pH 7–8.3, is kept in groups of 3 or more, and needs a tank of at least 100 L (26 gal).

At a glance

Type	Fish
Adult size	12 cm (4.7 in)
Minimum tank	100 L (26 gal)
Group size	3 or more
Temperature	72–82°F (22–28°C)
pH	7–8.3
Temperament	Semi-aggressive
GH	12–30
Lifespan	3–5 years
Eats shrimp	Yes

Before it goes in

Swordtail needs at least 100 L (26 gal). The smallest size in this library that clears that is the 29 Gallon.
Keep 3 or more. Below that it hides, colours down and is far more likely to be picked on.
It eats shrimp. Cherry Shrimp, Crystal Red Shrimp and Bamboo Shrimp are on the menu.
It holds at 72–82°F (22–28°C). That shares a window with Betta and Cherry Shrimp.
It is semi-aggressive — plan the tank around it rather than adding it to a finished community.
It jumps. An open-top tank needs a lid or a low water line.
It eats soft-leaved plants. Hygrophila corymbosa 'Siamensis' and Bacopa caroliniana will not last with it; tough-leaved Anubias nana 'Petite' and Marimo Moss Ball will.
A group of 3 takes up roughly 66% of what a 29 Gallon will comfortably hold, so plan the rest of the stock around it.

What tank size does it need?

At least 100 L (26 gal). The smallest size here that clears it is the 29 Gallon.

How many should I keep?

3 or more. Fewer than that and it spends its time hiding instead of out in the open.

Will it eat shrimp?

Yes. Shrimp are food to it, so pick one or the other.

What water does it want?

72–82°F (22–28°C), pH 7–8.3, GH 12–30.

How long does it live?

3–5 years in a tank that suits it. That is how long you are signing up for.

Good tank mates

Tank mates from this library that share its temperature window, are peaceful and eat neither it nor its young: Goldfish, Bristlenose Pleco, Celestial Pearl Danio, Molly and Otocinclus.
Plants that hold up with it: Anubias nana 'Petite', Marimo Moss Ball, Subwassertang and Anubias barteri.

Often compared with

	Swordtail	Platy	Boesemani Rainbowfish
Adult size	12 cm	6 cm	12 cm
Min tank	100 L	60 L	200 L
Group	3+	3+	6+
Temperature	72–82°F (22–28°C)	68–79°F (20–26°C)	75–82°F (24–28°C)
Eats shrimp	Yes	Shrimplets only	Yes

More livestock

Plan a tank with Swordtail →

Sources (4) · checked Sep 2026