Swordtail
Xiphophorus hellerii
A large, very active livebearer whose males carry a sword-shaped tail; it needs a long tank, a lid and hard water.
Key facts
- Body length
- 6.3 in without fins
- Minimum tank
- 34 gallons
- Group
- 3+
- Temperament
- Peaceful
- Care level
- 1 / 5
- Lifespan
- Not well documented
- Diet
- Flakes, pellets, spirulina, frozen bloodworm and brine shrimp
- Origin
- Southeastern Mexico to Honduras
- Hardier than87%
- Bigger than79%
- Calmer than68%
Water: their range vs yours
Swordtail tank mates
- Neon tetraGets along in shared water.Good mates
- Harlequin rasboraGets along in shared water.Good mates
- Fancy guppyGets along in shared water.Good mates
- Panda corydorasGets along in shared water.Good mates
- Cherry shrimpGets along in shared water.Good mates
- BettaGets along in shared water.Good mates
- AngelfishGets along in shared water.Good mates
- Tiger barbGets along in shared water.Good mates
- Amano shrimpGets along in shared water.Good mates
- Black neon tetraGets along in shared water.Good mates
- Black widow tetraGets along in shared water.Good mates
- Bristlenose plecoGets along in shared water.Good mates
- OtocinclusGreen swordtail outcompetes the slow-eating Otocinclus for food; target-feed to make sure it eats.Risky
- Blood parrot cichlidGreen swordtail outcompetes the slow-eating Blood parrot cichlid for food; target-feed to make sure it eats.Risky
- Blue dolphin cichlidBlue dolphin cichlid can eat young or small Green swordtail; adults are big enough to be safe.Risky
- Chinese algae eaterChinese algae eater attacks fish with a similar shape or colour: Green swordtail.Risky
- Clown loachClown loach attacks fish with a similar shape or colour: Green swordtail.Risky
- Convict cichlidConvict cichlid (aggressive) will bully the peaceful Green swordtail.Risky
- Iridescent sharkIridescent shark can eat Green swordtail: prey body depth 2.8 cm ≤ mouth 32.5 cm.Avoid
- OscarOscar can eat Green swordtail: prey body depth 2.8 cm ≤ mouth 12.3 cm.Avoid
- African clawed frogAfrican clawed frog should only be kept in a single-species tank.Avoid
- Marbled crayfishMarbled crayfish should only be kept in a single-species tank.Avoid
- AxolotlAxolotl should only be kept in a single-species tank.Avoid
- Bala sharkSilver shark can eat Green swordtail: prey body depth 2.8 cm ≤ mouth 8.8 cm.Avoid
How we check
The numbers the tank model uses for swordtails: water as ideal and tolerated ranges, bioload from adult mass, space, flow and how they act on other species.
- Standard length
- 16 cm (TL)
- Adult mass
- 48.37 g
- Bioload at 25 °C
- 13.33 BU
- Min. water
- 108 L net
- Min. footprint
- 120 × 30 cm per group
- Group
- 3+ (best 5)
- Swims in
- middle, top
- Flow
- moderate
- Body / fins
- fusiform, normal fins
- Diet type
- omnivore
- Fin nipper
- none
- Sensitive to
- —
Sources: Seriously Fish: Xiphophorus hellerii · FishBase: Xiphophorus hellerii
Care notes
Swordtails come from fast, rocky streams and springs from southeastern Mexico to Honduras. Females reach about 6.5 inches, males a little less plus the sword.
Give them a 4-foot tank of 29 gallons or more with hard water and a lid, as they are known jumpers. Males sort out a pecking order, so keep one male with several females, and expect them to crossbreed with platies.
Questions
What size tank does a swordtail need?
At least 34 gallons (108 litres of water after decor). Adults reach about 6.3 inches without fins.
How many swordtails should be kept together?
Keep at least 3, ideally 5 or more: fewer feel exposed and hide or turn nippy.
What water do swordtails need?
72–82 °F, pH 7–8 and 10–25 dGH. Swordtails come from Southeastern Mexico to Honduras.
How long do swordtails live?
Not well documented with good care.
What fish can live with swordtails?
Good tank mates include Neon tetra, Harlequin rasbora, Fancy guppy, Panda corydoras and Cherry shrimp. Each is checked both ways for size, fin nipping, temperament, territory and shared water.