Swordtail - Xiphophorus helleri
Updated May 14, 2020
Author: Mike - FishLore Admin
The Swordtail comes in many different colors with the males being easily identified by their signature sword like tail. This is an extremely hardy fish that can adapt to a wide range of water conditions.
They are livebearers which means that the baby fish come out free swimming. Like their livebearer counterpart, the guppy, this is a prolific breeder and a female will give birth about once every 28 days. If you are interested in breeding them, please check out the breeding livebearers page for more information.
Some hobbyists have reported problems with aggression among males when keeping multiples. It may be a good idea to limit the number of males in your tank. A good mix may be three females to one male.
Swordtail Fish Care Detail
Scientific Name : Xiphophorus helleri
Common Names : Black, Gold Tux, Green, Lyretail, Neon, Red Simpson, Spotted, Red Velvet, Black Velvet, Belize, Atoyac
Care Level : Easy, good fish for freshwater fish beginners
Size : Up to 5 inches (13 cm)
pH : 7 - 8
Temperature : 72°F - 82°F (22°C - 28°C)
Water Hardness : 9° to 15° dH
Lifespan : 3 - 5 years
Origin / Habitat : Central America
Temperament / Behavior : This is a tough litte fish. They can take care of themselves when there are bigger fish in the tank. The males may become aggressive towards other males.
Breeding : They are livebearers, so it is fairly easy for them to breed. Be sure to give a lot of floating cover for the baby swords. Try to put the babies in a separate tank otherwise the adult fish will eat them. To condition them for breeding a study was conducted showing that small frequent daily feedings (3 times fed per day) led to faster growth rates and better reproductive capability. I know, pretty obvious right?
If you want to try and raise the babies look into investing in a breeding box or breeder net like the following:
Aquarium Size : 10 gallon or larger
Tank Mates : Don't keep with tropical fish big enough to eat them. They should be able to handle themselves with many fish their same size or larger.
Fish Disease : Freshwater Fish Disease - Diagnose, Symptoms and Treatment
Diet / Foods : Omnivore but they need some greens in their diet. They will take flake, freeze dried and live foods.
Tank Region : All over the tank
Gender : Easy to determine - the male has a signature long anal fin.
Photo Credit : Photos copyright JJPhoto.dk
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Swordtail Comments and Tips
Hi. I have a female that had babies last night. When I realized she was having them I moved her and the babies to the breeding net. When I woke this morning the babies were dead (except 2). I moved the mom out and left the 2 babies in the net. Can you please tell me what might have caused the babies to die???
Hi Tammy. Without more information (such as ammonia, nitrite and nitrate levels) I would only be guessing as to what caused the death of your baby swords. Here are some possible causes:
- If it is a new tank that has not completed the aquarium cycle yet, you may have high ammonia or nitrite levels which are very toxic to fish. These are hardy fish that can sometimes tolerate these high levels but I don't think the babies would.
- If you have a cycled tank but haven't changed the water recently, your nitrate levels may be very high. Nitrate at low levels is not very toxic to fish, but at high enough levels it can become toxic to them. The babies may not have been able to tolerate the high nitrate levels.
- Sometimes your water parameters may be fine, not all babies make it. This could be attributed to the heavy inbreeding of the many types of tropical fish. Breeders go for certain colors and in so doing inbreed multiple times, thereby weakening the genetics of these fish. It's sad but true.
I bought three swords and they all died within a week. All of the conditions were right so I don't know what happened. They looked and acted normal except for right before they died they just swam in one spot and didn't move or eat. None of my other fish have died, just the 3 swords. Anyway, I am not going to get them (or buy fish from where I got them) again.
Sorry about your fish. This fish is usually fairly hardy and one of the last ones to die if the water parameters are out of whack.
How would you properly care for the baby fish?
You can give them finely crushed flake food, baby brine shrimp and/or finely crushed freeze dried blood worms. To get the best growth rate possible, try to change the tank water frequently, about once a week. You also need to siphon up any uneaten food so that it doesn't foul the water. Thats when keeping them in a tank without gravel really comes in handy.
How do I get my female pregnant? I have one male and two females in the tank right now but I don't know what will help them breed.
Provide them with good water by performing frequent Water changes and then wait. You could try bumping up the water a degree or two for a few days and see what happens.
How do I know when my female swordfish is pregant?
Look for a growing belly and a dark spot near the anal fin. This dark spot is also called the gravid spot and it may be difficult to see in some species of swords like the red velvet.
I have been breeding them and they are so amazing! Just watch out if the lid is off the tank, your swords WILL jump out!
I currently have 2 female and 1 male swordtail that are actively breeding. A lot don't make it, they get eaten as they're born, but we have had some success in a 20 gallon tank. We're breeding what looks to be marigold/velvet hi-fin females and the male is yellow and orange with a long, beautiful red tail. Some babies come out clear, some yellow, some orange and even some with dark brownish spots on their heads.
When my female green swordtail is about to give birth, I put her in the breeding net, along with some small plastic plants. If I'm around when the babies come, I watch and wait until she's about done, then drain about 2 or 3 gallons of water from the main tank into my 5 gallon fry tank. Then I take about a 4 foot length of air tubing and siphon the babies from the main tank to the fry tank. Once the mother is done birthing, I top off the fry tank with water from the main tank and leave the mother in the breeding net for a day or two so that she can recover her strength before being put in with the other fish again. The plastic plants offer some protection for the babies if I'm not around or awake when the big moment comes, because the mother will often start to eat the babies soon after giving birth.
I have swordtails and I saw one having babies in our 55 gallon tank. I moved her to the net in our 10 gallon tank. She had about 40 fry. How can I tell when my swordtails are close to giving birth.
You really just have to watch them closely, watch for swelling in the stomach region and make a note of when they last gave birth and then make an educated guess knowing that their gestational period is usually around 4 weeks. If this is the first fish birth for you, you'll just have to watch them closely. Look for them to become less active and maybe less hungry right around the time they are ready to release the fry. When it happens, write the date down and you'll have a better idea for when it will happen again. Time to get more tanks!
Related Fish Profiles
The Endler's livebearer species might be extinct in the wild. They have very similar care requirements as the guppy and the two are closely related.
One of the first species for beginning hobbyist to breed. The Guppy is a prolific breeder that can be quite hardy and colorful as well. Keep males separated from females if you don't want baby guppies!
Pictured is the black molly. These livebearers like some aquarium salt in the water and will give lots of fish babies. Be responsible and only breed them if you have a plan for what to do with all the fry.