Are Swordtail Fish Hardy?

By Nadine Oraby | 2020 Update

Are you planning to add swordtail fish into your tank but are confused if it is hardy? Knowing whether swordtails are hardy or not is essential for effectively populating your tank.

So, are swordtails hardy fish? Swordtail fish is definitely hardy and easily adjusts to a new environment. Being hardy helps the Swordtail to adapt to almost all water conditions making it a top priority fish for your tank.

This article will outline the character and nature of Swordtail fish so that you know what you are getting into before you actually buy one.

The nature of Swordtail fish

If you are thinking of adding Swordtails to your tank, then be sure that these species are extremely hardy and adjust well to almost all water conditions. Nevertheless, providing them with an ideal environment will definitely boost their health and life.

Swordtail fish is famous for being hardy and adaptable. This fish is one of the most sought-after fish, especially by amateur aquarists. The reason behind their being so famous is definitely their easy-going nature. The name of this fish is derived from its distinctive sword-like tail that differentiates it from others. This live-bearing fish is very adaptive and will definitely not give you a hard time.

Despite Swordtail fish being hardy, they thrive in open spaces. To ensure healthy Swordtails, provide them with a big aquarium of at least 29 gallons if you plan on keeping a small group (4-5 of them). Since Swordtail fish are extremely active, large spaces are required for them to thrive. With that being said, make sure that you have their tanks covered because swordtails are athletic and can jump right out of the tank.

As mentioned earlier, Swordtail fish are extremely hardy, making them an excellent community fish. Generally, they are peaceful in nature. However, male Swordtail can tend to be a little aggressive. It is therefore advised to maintain a 3:1 ratio of female to male swordtails. Additionally, to ensure that your Swordtail blooms, avoid placing big fish into the tank as your Swordtails might feel intimidated by them.

Aquarium size

Even though Swordtail fish are hardy in nature, to ensure that they grow well, it is essential that their aquarium needs are met. Despite the fact that these fish are average-sized, they are extremely active and love swimming around, thus it is advised to provide them a spacious aquarium. If you plan on keeping just a trio of swordtails, then a 15-gallon water tank would provide them a healthy environment. But if you plan to add Swordtails with some other species in the tank as well, then you will need a 29-gallon aquarium.

As mentioned earlier, Swordtails are extremely active. Make sure that your tank is large enough and has a lid placed on top as swordtails are amazing jumpers and may jump right out of the tank.

Swordtail | Hardy Beautiful & Easy to Care | Beginner Fish (Video)

Swordtail Fish diet

Swordtail fish are omnivores; this means that they eat almost everything, be it live, fresh or flake. Since these fish are very tough, they are good with almost all kinds of fish food. However, it is advised that they are fed more greens as they tend to eat a lot of algae in their natural habitat. They are active fish and love eating live food like brine shrimp and blood worms. Swordtail fish don’t tend to give you a hard time and will eat almost all fish foods: flakes, freeze-dried, frozen and live.

Even though they are tough and hardy, it is essential that their dietary needs are met and a balance is created between vegetables and protein.

Ideal Tank Companions

Swordtail fish are tough little creatures that can survive on their own. Unlike many other small fish, they are not at all boring. They are peaceful creatures that gel in well with closely related breeds like Platy and Mollies. They even go well with other passive species. Another option for possible swordtail tank mates could be Corydoras and a few larger types of Tetras.

It is seen quite often that the male Swordtails tend to get aggressive with each other. If that is the case with your tank, then make sure you place at least four female fish for one male so that the aggression dims over time. However, it is better if only one male Swordtail is kept while all other fish are female.

Breeding Swordtail Fish

Swordtail fish are livebearers. This means that they give birth instead of laying eggs. These fish are hardy and self-sufficient when it comes to breeding and require no intervention from the aquarist. All you need to do is place them in the tank and Voila! They will start breeding away.

A pregnant female Swordtail can be easily identified by its round belly and a distinctive grey spot near her anal fin. These fish are not that smart and may not know the difference between their fry and food. It is thus advised to either increase the number of plants when fry are born, so as to provide them with hiding spots, or to move them to another tank till they are big enough to survive on their own. The ideal time to place the fry back in the community tank is when they get large enough as to not fit into the adult swordtails’ mouth.


Famous for being extremely hardy and playful, Swordtail fish are one of every beginner aquarist’s top choices. Despite the fact that these fish are so adaptive in nature, it is important that special care and attention is given to them so as to ensure that they reach their full potential and live a healthy life.

Here is a short recap for you to tally:

  • Ideal tank size is 25-29 gallons
  • Best ratio of male to female is 1:4
  • Required pH is 7.0-8.0
  • It is an omnivorous breed that eats almost anything
  • The males have a sword-like extension in their anal fin while females have a rounder anal fin
  • Make sure you balance the proteins and vegetables so as to fulfill your swordtails dietary needs
  • Put a lid on your tank as these fish are good jumpers
  • Compatible with almost all passive species, however ideal as a single aquarium species.

Related questions

How to tell the gender of your Swordtail fish? Unlike the closely related Platy fish, the Swordtail fish’s sex can be easily identified. Male Swordtails have a pointed extension to their anal fin that resembles a sword while the female’s anal fin is much rounder and fan-shaped. Additionally, females are more round and fuller and may grow 1 to 1.5 inches by the time they attain maturity.

What is the origin of Swordtail fish? Discovered in 1848, Swordtail fish originated from the North and Central America. These fish are freshwater tropical fish with a lifespan of 1 to 2 years on average (although with proper care, you can expect them to live for 3-5 years). Often referred to as Red Swordtails or Green Swordtails, their scientific name is Xiphophorous helleri.


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