Swordtails with shrimp
The green swordtail, Xiphophorus hellerii, is a livebearer from southeastern Mexico, Guatemala, Belize and Honduras, named for the sword-like extension on the male's tail (Seriously Fish). It is one of the most recognizable aquarium fish, and selective breeding and crosses with platies have produced varieties such as koi, high fin, lyretail and pineapple (Seriously Fish, Aquarium Co-Op). Because swordtails are close relatives of platies, keepers often ask whether they can share a shrimp tank too.
Swordtails at a glance
| Green swordtail (Xiphophorus hellerii) and hybrids | |
|---|---|
| Adult size | 140 mm (6 in) SL (Seriously Fish); 4–6 in (Aquarium Co-Op) |
| Temperature | 61–82 °F (16–28 °C) (Seriously Fish); 70–80 °F (Aquarium Co-Op) |
| pH | 7.0–8.0 (Seriously Fish); above 7.0 (Aquarium Co-Op) |
| Hardness | 10–25 dGH (Seriously Fish); higher GH (Aquarium Co-Op) |
| Tank | Base of at least 48 × 12 in (120 × 30 cm), about 29 US gallons (Seriously Fish) |
| Diet | Generalist omnivore; wild fish eat aquatic and terrestrial invertebrates, detritus, algae and plants (Seriously Fish) |
| Temperament | In confined spaces, males form dominance hierarchies and spend much of their time defending their rank (Seriously Fish) |
Will swordtails eat shrimp?
- Shrimplets: yes. Seriously Fish says stomach analyses of wild swordtails show they eat aquatic invertebrates, and it recommends small live and frozen foods such as daphnia and brine shrimp. A newborn shrimp is the same kind of prey (our reading).
- Adult shrimp: at risk. A 4 to 6-inch fish can fit a small cherry shrimp in its mouth, and Practical Fishkeeping says fish often eat anything that fits (our reading for swordtails).
- Molting shrimp: the most vulnerable adults (our reading).
- Stress: Practical Fishkeeping says shrimp kept with predatory fish hide more and breed less.
Practical Fishkeeping says that with larger livebearers it's "not a matter of if but when" they eat your shrimp. Swordtails are the largest of the common livebearers (Aquarium Co-Op), so we rate them a step above platies. Compare platies with shrimp and mollies with shrimp, or see the full cherry shrimp tank mates list.
Matching the water
Seriously Fish lists 61–82 °F, pH 7.0–8.0 and 10–25 dGH for green swordtails, and Aquarium Co-Op says they like pH above 7.0, higher GH and 70–80 °F. The Shrimp Farm lists 65–80 °F, pH 6.8–8.0, GH 4–8 and KH 2–5 for cherry-type shrimp. By our comparison, temperature (65–80 °F) and pH (7.0–8.0) overlap well, but the hardness ranges miss by about 2 dGH, the same gap as with platies: the shrimp's top is GH 8 and the swordtail's bottom is GH 10. Water is the smaller problem here; size is the bigger one. See shrimp GH and KH explained.
Tank size, males and fry
- Size: Seriously Fish says a base of 48 × 12 in is the smallest to consider, with some water movement, floating plants and driftwood. That's far larger than a typical shrimp tank.
- Males: rival males establish dominance hierarchies (Seriously Fish), so a cramped tank means constant chasing.
- Fry: swordtails breed like other livebearers, and Seriously Fish notes females can store sperm for months, so a female can keep producing fry without a male. More fish mean more mouths (our reading).
- Platy crosses: Aquarium Co-Op warns that swordtails and platies interbreed, so keep them apart if you don't want hybrids.
Better options
- Breeding shrimp? Keep them in their own tank. This is our recommendation.
- Want the swordtail look in a small tank? Platies are close relatives at about 2 in; see platies with shrimp.
- Already have swordtails? Adult Amano shrimp are larger than cherry shrimp; see Amano shrimp care.
If you try it anyway
- Big tank, shrimp first. Practical Fishkeeping says to give the colony time to build up before adding fish.
- Dense cover at the bottom. See baby shrimp care and java moss for shrimp.
- Feed the fish well, which Practical Fishkeeping says reduces losses.
- Acclimate slowly. See how to drip acclimate.
- Quarantine the fish separately. Practical Fishkeeping says many fish medications are not safe for invertebrates. If fish get sick, ask a fish veterinarian or an experienced store about treatment that won't harm the shrimp. See how to quarantine and is copper toxic to shrimp.
Common mistakes
- Treating swordtails like platies; they grow two to three times as long.
- Keeping several males in a small tank.
- Putting swordtails in a 10 or 20-gallon shrimp tank.
- Expecting a shrimp colony to grow alongside a livebearer population.
Track it
Log temperature, pH, GH and TDS on the free Water Parameter Log printable so you can keep the tank in the range both species share.
Frequently asked questions
Will swordtails eat cherry shrimp?
They will eat shrimplets, and a 4 to 6-inch swordtail can eat small or molting adults. Practical Fishkeeping says larger livebearers do not belong with shrimp. We rate swordtails a high risk.
Can cherry shrimp breed with swordtails?
Very few babies are likely to survive. Use a separate shrimp tank if you want the colony to grow.
What water do swordtails and cherry shrimp share?
About 65 to 80 °F and pH 7.0 to 8.0. Seriously Fish lists GH 10 to 25 for swordtails and The Shrimp Farm GH 4 to 8 for cherry shrimp, a small gap.
How big a tank do swordtails need?
Seriously Fish recommends a base of at least 48 by 12 inches, about 29 gallons.
Are swordtails or platies better with shrimp?
Platies. They are about 2 inches long; swordtails reach 4 to 6. We rate platies a moderate risk and swordtails a high risk.
Can swordtails live with Amano shrimp?
Adult Amanos are larger than cherry shrimp, so in our reading they are safer, though not guaranteed with big swordtails.
Sources: Seriously Fish, Xiphophorus hellerii (green swordtail) (southeastern Mexico, Guatemala, Belize and Honduras; 140 mm SL; base 120 × 30 cm, about 29 US gal; 16–28 °C, pH 7.0–8.0, 10–25 dGH; generalised omnivore eating aquatic and terrestrial invertebrates, detritus, algae and plants; small live and frozen foods; male dominance hierarchies in confined spaces; females store sperm for months; hybrids with platies); Aquarium Co-Op, Top 10 livebearer fish to try breeding (swordtails 4–6 in, one of the larger livebearers; mostly crossed with platies; pH above 7.0, higher GH, 70–80 °F; keep apart from platies to avoid hybrids); Practical Fishkeeping, What can I keep with shrimp? (larger livebearers don't belong with shrimp; fish eat what fits in their mouths; shrimp hide and breed less with predators; medications not invertebrate-safe); The Shrimp Farm, Red rili shrimp tank set-up and care (cherry-type range 65–80 °F, pH 6.8–8.0, GH 4–8, KH 2–5).