TankBud

One species · 6 varieties

Green swordtail

Xiphophorus hellerii

Also known as Xiphophorus helleri

FreshwaterFish

Green swordtail (Xiphophorus hellerii)
Imperial Tropicals · Used with permission

Care at a glance

Temperature
68–82°F
20–28°C
pH
7.0–8.0
Adult size
5.9 in
15 cm
Minimum tank
20 gal
76 L
Temperament
Peaceful
Social behavior
Social
Swim level
Middle
Difficulty
Beginner
Breeding
Livebearer · Easy
Rarity
Very common
Family
Poeciliidae
Origin
Mexico, Central-America

Pick a variety

One setup covers every line on this page: care is the species' care.

Overview

The green swordtail is a peaceful, active livebearer for a community tank with some length to it. It is easy to keep and a good first fish.

Did you know

A swordtail that seems to turn from female to male is often a male that matured late. True sex reversal is rare, but a few females that had already given birth have become fertile males.

Caring for the green swordtail

Keep green swordtails in a small group in a tank of at least 20 gal (76 L). They are active swimmers in the middle of the tank and appreciate length to cruise. Give them planted edges, open space in the middle and moderate flow, like the streams they come from.

Keep the water hard and alkaline, at 68 to 82°F (20 to 28°C) and a pH of 7.0 to 8.0. Swordtails are easy eaters that take a quality flake or pellet with some vegetable matter. Add the odd frozen treat.

They are peaceful and safe with other community fish. Keep more females than males to spread out the males' attention. Males grow a long sword extension on the lower tail fin. Females are larger bodied but lack the sword.

Green swordtails bear live young rather than laying eggs. A female can store sperm and produce several broods from one mating. They breed readily, so expect fry and give the babies plants to hide in.

Good to know

Xiphophorus hellerii is a livebearer in the family Poeciliidae, and it is fairly large for a community fish. Its name is also spelled Xiphophorus helleri.

In the wild

Green swordtails come from warm rivers, streams and springs in Mexico and Central America. They often live in flowing water with plenty of plants.

Other named lines

Wild swordtails are green. Nearly every shop swordtail is a line-bred color of the same fish, with platy crosses behind some of the patterns.

Hi-fin
tall sail dorsal; also sold as Simpson swordtail

Weekly picks

Tank mates

Every variety on this page wants the same water, so one set of picks fits them all. These picks match on water type, temperature, pH, size and temperament.

Check the full mix in the stocking calculator

Common questions

What size tank does a green swordtail need?

A green swordtail needs at least 20 gal (76 L). It spends most of its time in the middle.

What temperature and pH does a green swordtail need?

A green swordtail is comfortable at 68–82°F (20–28°C) with a pH of 7.0–8.0.

What does a green swordtail eat?

A green swordtail is an easy eater that takes a quality flake or pellet with some vegetable matter. Give it the odd frozen treat as well.

How big does a green swordtail get?

An adult green swordtail reaches about 5.9 in (15 cm).

How can you tell a male green swordtail from a female?

Males grow a long sword extension on the lower tail fin. Females are larger bodied and lack the sword.

How does a green swordtail breed?

A green swordtail bears live young, and a female can store sperm for several broods from one mating. It breeds readily, so give the fry plants to hide in.

Related species