Expanded Fish Care

Swordtails

Kingdom: Animalia

Phylum: Chordata

Class: Actinopterygii

Order: Cyprinodontiformes

Family: Poeciliidae

Genus: Xiphophorus

Species: Xiphophorus helleri

Care level-Easy to Expert

Temperament and Behavior- Active peaceful swimmers, are often found in the top to mid-level of the tank, but not uncommon to see them along the substrate looking for bits of food.

Lifespan- Up to 5 years  

Size- Up to 5+ inches

Diet- Omnivores

It is important to feed a variety of high-quality foods that are rich in proteins. Flakes are a staple in the fish room and are the most fed food: Tetra Flakes or Extreme Krill Flakes are favorites. However, providing a varied diet is essential, offer granules like Fluval’s Bug Bites (made with mosquito larva) or a treat of frozen foods. Swordtails enjoy frozen or live food; however, this food is a special treat in my fish room. Feeding time is an enjoyable time to watch and learn the individual personalities of your swordtail fish. Remember providing smaller food portions is better than overfeeding. Dumping too much food in your aquarium will only allow food to mold in your tank, throwing off your nitrogen cycle. Watch and get to know your fish and only give the proper severing they will eat. 

Minimum Tank Size-20-gallons 

pH-7.0-8.2

Water Hardness- Harder water recommended 

Temperature- 65-82 degrees Fahrenheit 

Tank-Mates - Swordtails are a great addition to any community aquarium, but still not recommended with aggressive fish species. Nevertheless, you could try Tetra, Mollies, Platy fish, a small Plecostomus- Clown Pleco, Amano Shrimp, Dwarf Gourami, or anything peaceful in nature. Do not recommend fish like cichlids, which can be aggressive at times.

 Recommended Group Size- Swordtails, in my option, even though not required, do better in the company of fellow swordtails. 

Male v. Female- Having the characteristic swordtail is a sure-fire way of identifying the males in your group. Females are beautiful, stunning fish, but typically you only see the characteristic swordtail or caudal (tail) fin in males. Females have a rounded tail fin like other fellow livebearer females. Female Swordtails have a gravid spot that gradually darkens when carrying fry like other livebearer species. The gravid spot is a darkened circular spot on the belly above the anal fin. This spot will enlarge and darken with pregnancy. Females will also have a triangular anal fin, whereas males have a stick-like modified anal fin called a gonopodium. It's important to know that it's best to separate males from females or only keep one gender if you do not wish to breed. Remember that livebearers are all part of the Family Poeciliidae. However, breaking it down further, both Platy's and Swordtails are part of the genus Xiphophorus. Only species of the same genus can crossbreed and produce offspring. Swordtail's and Platy's fish can have fry together. I believe they are fertile, but they have meager reproduction rates. Swordtails cannot crossbreed with Guppies or Mollies. Yes, they are in the same family but categorized in a different Genus as Guppies. 

Fry--Swordtails reach sexual maturity reasonably quickly, around two or three months of age, meaning they can reproduce at this age. Swordtails can drop fry (offspring) every four weeks upon sexual maturity. However, in my experience, they do hold fry longer compared to other livebearers in the fish room. Females also can drop 50+ fry. The average drop in my fish room is 10-15, and the females may birth more fry; however, I do lose offspring due to the parents predating and eating them. I provide a heavily planted tank to allow the fry to hide and grow, mainly Vallisneria. Providing hiding spots, proper feedings, or having a separate grow-out tank will improve the odds of fry reaching maturity. 

Most female livebearers, including Swordtail fish, will internally fertilize eggs, and these eggs will develop and hatch inside the mothers before being born alive. Swordtail females, like guppy females, being ovoviviparous allows them to have the capability of holding sperm. If your swordtail female was cared for in the same tank as a male at any point, there is a high probability she is pregnant with babies. If removed and no longer exposed to a male, the females can still produce another generation even with no current mate. 

Tank Setup- Both of the swordtail species I keep in the fish room often swim in the water flow, seemingly enjoying the filter's output flow. Usually, you will see them actively playing in the filter's outflow. The two swordtail aquariums in my fish room are cared for similarly regarding the setup and maintenance schedule. The Calico Koi Swordtail trio enjoys a heavily planted 20L-gallon long aquarium and the Neon Swordtails in a 30-gallon. The Calico Koi Swordtails tank is a low-tech tank, only lit from a clamp shop light full of Vallisneria plants (Vallisneria nana) and Guppy Grass. The 30-gallon tank is lit by a Fluval light and also full of Vallisneria (Vallisneria nana) and Guppy Grass. Both aquariums hold a few rocks that I collected from the yard, small local pea gravel substrate, and CaribSea Natural Torpedo Beach Sand. 

*Don't forget to give them adequate rest time by remembering to turn off the lights.