Swordtail: Care, Size, Lifespan, Diet & More

Swordtail fish (Xiphophorus helleri) is a popular choice for freshwater aquariums. They are active and sociable species that can bring life and color to any tank. The unique sword-like structure on their tails makes these fish very different from other fish.

In this article, you will be provided with the necessary instructions for taking care of Swordtails as well as any other information that may be useful.

Species Profile & Overview

Swordtail fish are native to Central America and Mexico, where they inhabit a variety of freshwater habitats. In the wild, Swordtails typically live in large numbers forming social groups but they will not school as some species might do. 

Swordtails belong to the Xiphophorus genus which has 28 known species. Of these 28 species, some develop a sword-type structure on their tail known as swordtail fish. The others that don’t develop this sword structure are known as Platy Fish.

The Swordtails commonly seen in aquariums are a mix of different species of the Xiphophorus genus and are line bred to develop unique colors and patterns that are not common in the wild. The 28 species in the Xiphophorus genus can interbreed with each other.

Swordtails are known for their active behavior in the aquarium. They are peaceful fish that can get along well with most other community fish. These fish have become popular among aquarists due to their hardiness and attractive coloration.


Male Red Swordtail
Red Swordtail

The Swordtail fish is a beautiful and vibrant species that stays small. These fish are known for their long, slender bodies with distinctive sword-like tail fins. This gives them their name, as the tail resembles a small sword or saber.

However, it’s only the males that have a sword shape growth on their tail fin. This makes identifying their gender very easy. 

When placed in an aquarium environment, Swordtails make quite an impression with their colorful patterning and distinctively shaped fins! Especially when the aquarium is fully planted and fish explore the plants.

These fish come in a variety of colors and patterns ranging from solid black to bright reds and oranges. Some even have stripes while others may have spots or speckles on their body. 

No matter what color they are, all Swordtails have an unmistakable beauty about them that makes them stand out among other aquarium inhabitants.

Adult Size

Swordtail fish are small, slender-bodied fish that typically grow to be around 5.5 inches in length. Some specimens can grow slightly larger or smaller. 

Males usually have smaller bodies but with their swords, they can be slightly lengthier than the females. This makes them easy to distinguish from the females, who lack this feature.

Their relatively small size makes them ideal for beginner aquarists as they don’t require a large space. Additionally, they are hardy and adaptable which means they can thrive in smaller tanks.


Swordtail fish is a species of tropical freshwater fish that can live from 3 to 5 years in captivity. In the wild, they typically have a shorter lifespan due to predation and other environmental factors. 

Factors that can affect the lifespan of Swordtail Fish include water quality, diet, stress levels, tank size, and overcrowding. Following the right care recommendations, we made in this guide will help your fish reach their maximum expected lifespan. 

Behavior & Temperament

Swordtail fish are typically very peaceful but active species. They enjoy swimming around the tank, exploring their environment, and interacting with other fish in the tank. They are very peaceful towards other fish.

Swordtail fish are good community tank fish, as they are peaceful and get along well with other species. It’s best to keep them in small groups of 3 – 5 individuals with one male and the rest being females.

It’s important to keep fewer males and more females in a tank. This is because the males will often chase the female and try to mate with them. Too many males will increase the stress levels in females. 

These fish will eat any small creatures that can fit in their mouth. They will also eat their own newborn fry. So it’s important to not add smaller creatures like freshwater shrimps to their tank. 

Overall, swordtails are fascinating fish with calm personalities that make great fish for entertaining. With proper care and maintenance, these active little fish will bring joy to any home aquarium for years to come.

Swordtail Care

Swordtail fish is a great choice for beginner aquarists due to their hardy nature and ease of care. All they demand is regular water changes, good filtration, and a proper diet. 

Swordtail fish are incredibly adaptable species and can survive in a wide range of aquarium parameters. As long as the tank has stable pH levels and temperature you can expect these fish to thrive. 

Despite their high adaptability, it is best to know the best range of parameters and tank environments they need. So keep reading the next few sections to make sure your fish can experience their best life with you.

Tank Size

Swordtails need a minimum tank size of 10 gallons but it’s best to have them in a larger tank. This is because the Swordtail fish can grow up to 6 inches in length, so they need enough space to swim around freely. 

In this tank size, you can comfortably house two or three Swordtails as long as there are plenty of hiding places for them to feel secure. It’s important not to overcrowd the tank with too many fish, as this could lead to stress and possibly bullying.

If you want to have a larger group of Swordtail fish, then you’ll definitely need a bigger aquarium. A larger tank will provide more space for the fish to swim around and explore. At the same time, you will not run into overcrowding problems as they continue to breed. 

Regardless of the number of fish you want to have, a large aquarium can have many benefits. A larger tank provides more space for the fish to swim and explore, which helps reduce stress levels. This in turn can lead to better health and longer lifespans. 

So we recommend having a tank of 30 to 50 gallons if you want to give your fish a better living area.

What To Put In A Swordtail Tank

Decorating the tank is definitely the most fun part of keeping any aquarium fish. For swordtails, you are in luck as these fish can live in any tank design you create. But it’s best to give them plenty of plants so they feel more comfortable. 

Plants are an essential part of keeping these fish thriving since they hunt and eat their newborns. Live plants will provide the fry with enough hiding spaces to take refuge from larger fish. 

At the same time, plants will remove the toxins from the water making the tank a healthier space for your fish. You can use almost any type of plant you want but it’s probably best to pick fast-growing Aquarium Plants

If you want to go with water column plants like Buce Plants, Hornwort, or Anubias then you can pick any substrate. These fish do not have any preference when it comes to the substrate so it’s best to pick the substrate based on the plants you want to keep. 

You can also create more hiding spots by carefully selecting and placing the decorations in the tank. By adding natural decorations like driftwood and aquarium rock, you can create a more aesthetically pleasing tank for humans and fish. 

Light Requirements

Swordtails can live in any lighting conditions but they look their best in moderate to bright lighting conditions. High-quality light can help bring out the vibrant colors of Swordtails and make them appear more beautiful. 

High-quality lights also benefit plants by providing the right amount of intensity, spectrum, and duration for photosynthesis. This helps promote healthy growth and development in aquatic plants, which is beneficial for any aquarium environment.

Male Red Swordtail
Red Swordtail

When buying lights for your aquarium, it is important to consider what type of lighting you need based on the species and desired look you want to achieve. Generally, most LEDs are the best option for planted aquariums. 

Pay attention to the Kelvin rating which indicates how warm or cool the light is. 40000K to 60000K lights are ideal for aquariums with plants.

Water Conditions & Parameters

Swordtail fish are also quite hardy and can adapt to a wide range of water parameters. However, it is still important to match the water parameters in your tank to the natural habitat of this fish if you want them to be as healthy as possible. 

Swordtails are native to slow-moving, warm waters of Central and South America. Maintaining these conditions in the aquarium is beneficial for these small fish as it allows them to live in an environment that closely resembles their natural habitat. This helps reduce stress and promote good health.

Here is the ideal range of parameters for Swordtail:

  • Temperature: 70 – 82 Degrees Fahrenheit 
  • PH: 6.5 – 7.5
  • TDS: 100 – 250 PPM

As long as your tank has consistent parameters that fall within the above-mentioned range your swordtails will thrive!

To keep the parameters consistent in a tank, you should do regular weekly water changes and never overfeed your fish. This will prevent fluctuating parameters in the tank and your fish will enjoy a healthier life.

Filtration System

Using a good filter in a fish tank helps to prevent waste from accumulating and reduces harmful ammonia and nitrate levels. Various types of filters can be used in a Swordtail tank. But it is best to choose one that is strong enough to clean the water without causing too much water movement.

A hung-on-back filter or a sponge filter can be good options for a Swordtail tank. Be sure to select a filter that is appropriate for the size of your tank.

Overall, a combination of filtration, regular water changes, and proper water temperature can help to create a healthy and conducive environment for Swordtail fish. By following these best practices, you can enjoy watching your Swordtail fish thrive and live a long, healthy life in your tank. 

Common Diseases and Prevention

Some common diseases that can affect Swordtail fish include bacterial infections, parasites, and fungal infections. These diseases can cause symptoms such as cloudy eyes, redness or swelling of the skin, lethargy, loss of appetite, and abnormal behavior.

To prevent these diseases, it is important to maintain a clean and healthy environment for the fish. This includes regularly cleaning the tank, performing regular water changes, and maintaining the proper water temperature and chemistry. It is also important to avoid overfeeding the fish, as excess food can contribute to the buildup of waste and harmful bacteria in the tank.

In addition, it is a good idea to quarantine any new fish before adding them to the tank to ensure that they are healthy and not carrying any diseases. 

If your fish got sick, it is always a good idea to consult with a veterinarian or professional who specializes in fish health if you suspect that your Swordtail fish may be sick. They can provide a diagnosis and recommend treatment options.

Diet and Feeding Requirements

Swordtail fish are omnivores and their diet consists of a variety of small invertebrates, plants, and algae. In captivity, Swordtail fish can be fed a variety of commercial fish foods, such as pellets, flakes, and frozen or freeze-dried foods. It is also possible to feed them live or frozen foods, such as brine shrimp, bloodworms, and daphnia.

It is important to feed Swordtail fish a varied diet in order to provide them with the nutrients they need to thrive. A good rule of thumb is to offer them foods that include both plant-based and protein-based options. It is also important to avoid overfeeding them, as excess food can lead to waste and water quality issues.

In terms of feeding schedule, it is generally recommended to feed Swordtail fish small amounts of food several times per day. This mimics their natural feeding behavior and allows them to graze throughout the day. It is also important to only offer them as much food as they can consume in a few minutes, and to remove any uneaten food from the tank to prevent it from decaying and contaminating the water.

As for the best time to feed Swordtail fish, it is generally recommended to feed them in the morning and evening. This allows them to have a consistent food source throughout the day and helps to maintain their health and energy levels. It is also a good idea to observe your fish and adjust the feeding schedule as needed based on their individual needs and behaviors.

Breeding Swordtail

Swordtails are livebearer (give birth to live fry) fish, and it’s relatively easy to breed them in captivity. They can breed frequently if provided with the right conditions. These fish will breed almost every month with a proper diet and tank setup.

In order to breed Swordtail fish in a tank, you will need to have at least one male and one female fish, However, it is generally recommended to have one male for every two to three females. This can help to prevent the males from becoming overly aggressive and harassing the females.

You should have a large enough tank to accommodate the breeding pair and any resulting fry. It is also important to provide the fish with plenty of hiding places and plants, as well as stable and suitable water quality and temperature. 

As you should know by now these fish will eat their newborn fry so it’s important to have plants in the tank so the fry can hide. This will greatly increase the fry’s survival rate. 

The best water parameters for breeding and raising Swordtail fry include a water temperature of 74-78 degrees Fahrenheit, a pH of 6.5 – 7.0, and lower hardness levels. 

It is also important to maintain good water quality by performing regular water changes and keeping the tank clean.

Swordtail fish can breed frequently, and they can produce several hundred fries per year. The exact number of fry will depend on the size of females but they generally give birth to about 30 – 40 fry each breeding cycle.

Once Swordtail fish give birth, if possible, it is recommended to separate the fry from the adult fish. This is because the adults may eat the fry if they are not removed, and it can also help to feed the fry much more efficiently.

Tank Mates

It is important to choose tank mates that are peaceful and non-aggressive, as Swordtail fish are relatively small and peaceful fish. Avoid choosing fish that are known to be aggressive or territorial. These fish will bully or harm the Swordtails.

Choosing tank mates that are similar in size to Swordtail fish is important as larger fish can bully or eat them. It is also important to consider the size of the tank when choosing tank mates. Overstocking the tank can lead to poor water quality and stress for the fish.

Considering these points, here are our top picks of tankmates for swordtail species:

Male Red Swordtail
Red Swordtail


Swordtail fish are a great addition to any aquarium, as they bring vibrant colors and active personalities. They are easy to care for and can be kept in groups or alone. Swordtails have unique characteristics that make them stand out from other species of fish, such as their long sword-like tails and the variety of color patterns they come in. 

With proper care, these fish can live up to five years in captivity, making them an ideal choice for beginner aquarists.

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Xiphophorus helleri