Overview
The Green Swordtail (Xiphophorus hellerii) is a freshwater fish belonging to the family Poeciliidae. It thrives at temperatures of 22–28 °C with a pH of 7.0–8.3, and requires a minimum tank volume of 110 litres. Known for its peaceful community fish; males may fight each other, it is considered a beginner-level species. Females can spontaneously change sex to functional males; active jumpers — keep tank covered. Water changes of 25–30 % weekly, stable parameters, and appropriate tank mates are key to long-term success with this species.
Scientific Classification
| Rank | Classification |
|---|---|
| Family | Poeciliidae |
| Genus | Xiphophorus |
| Species | Xiphophorus hellerii |
| Water type | freshwater |
| Native range | Reunion|Martinique|North America|Oceania|Afrotropical|Australasian|Neotropical|Oriental (Indomalaya)|Palaearctic|Pacific (Oceania) |
Natural Habitat
Xiphophorus hellerii originates from Reunion|Martinique|North America|Oceania|Afrotropical|Australasian|Neotropical|Oriental (Indomalaya)|Palaearctic|Pacific. It inhabits freshwater environments and is adapted to the water conditions found in its native range.
Appearance
Adults reach Males 10–12 cm (with sword); females 12–16 cm in length. The body is freshwater and the species displays characteristic coloration suited to its environment.
Behavior
This species is described as a peaceful community fish; males may fight each other. It does not school and can be kept individually or in small numbers. Activity level is high. Females can spontaneously change sex to functional males; active jumpers — keep tank covered.
| Trait | Value |
|---|---|
| Temperament | peaceful community fish; males may fight each other |
| Schooling | No |
| Activity level | high |
Water Requirements
| Parameter | Ideal Range | Notes |
|---|---|---|
| Temperature | 22–28°C (72–82°F) | Use a reliable adjustable heater |
| pH | 7–8.3 | Avoid sudden swings |
| Hardness (GH) | 12–30 dGH dGH | Soft to moderately hard |
| Ammonia | 0 ppm | Any detectable ammonia signals a problem |
| Nitrite | 0 ppm | Toxic even at low levels |
| Nitrate | <25 ppm | Manage through regular partial water changes |
| Min. tank | 110L (29 gal) | Larger tanks are easier to keep stable |
Interesting Facts
- The elongated 'sword' is an extension of the lower caudal fin rays and is exclusive to males.
- Female Swordtails prefer males with longer swords — one of the first documented examples of mate choice in fish.
- Swordtails readily hybridise with Platies (Xiphophorus maculatus), producing fertile offspring.
📋 Full Care Guide
Ready to set up a tank for your Green Swordtail? The complete care guide covers tank setup, feeding schedule, common diseases, tank mates, and breeding.
Read Green Swordtail Care Guide →Related Species
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This species profile was reviewed for biological accuracy and practical aquarium care guidance. For suspected illness or disease, test your water parameters first and consult an aquatic veterinarian if symptoms persist.