Swordtail Fish – Care, Tankmates, Feeding, Breeding & Details

Welcome to the captivating world of Swordtail fish, a realm filled with vibrant colors, dynamic behaviors, and a fascinating life cycle.

These freshwater species, known scientifically as Xiphophorus helleri, are a popular choice among aquarists, from beginners to seasoned enthusiasts, and for good reason.

Swordtail fish are renowned for their striking appearance, characterized by their elongated lower lobe of the caudal fin, which resembles a sword, hence their name.

Their bodies are adorned with a variety of colors, ranging from olive-green in the wild to a spectrum of red, orange, and black in captivity, thanks to selective breeding.

But there’s more to these fish than just their good looks. Swordtails are hardy, adaptable, and relatively easy to care for, making them an excellent choice for those new to the hobby.

They are also peaceful and sociable, making them ideal candidates for community tanks.

Moreover, Swordtails are livebearers, meaning they give birth to live young, a trait that adds an extra layer of intrigue to their care.

Watching a new generation of Swordtails come into the world and grow is a rewarding experience that offers a glimpse into the wonders of aquatic life.

In this comprehensive guide, we will delve deeper into the world of Swordtail fish, exploring their care requirements, diet, breeding, and much more.

Whether you’re considering adding these beautiful creatures to your aquarium or simply wish to learn more about them, this guide is designed to provide you with the knowledge you need.

So, let’s embark on this journey into the captivating world of Swordtail fish.

Quick Stats About Swordtail Fish

Information Chart Swordtail Fish
Scientific Name Xiphophorous hellerii
Family Poeciliidae
Care level Easy
Temperament Peaceful
Color Olive green
Lifespan 3-5 years
Size Up to 6.5 inches
Diet Omnivore
Minimum tank size 10-20 gallons
Temperature 70-82°F
Water conditions Freshwater with low stream
Tank mate compatibility Peaceful temperament and sociable

Appearance of Swordtail Fish

Swordtail fish, or Xiphophorus helleri, are renowned for their distinctive appearance, which makes them a favorite among aquarium enthusiasts.

The most striking feature of these freshwater species is the elongated lower lobe of the male’s caudal fin, which resembles a sword and can be as long as the rest of the body.

This unique trait allows for easy differentiation between males and females, as the latter lack this extension.

Beyond this signature characteristic, Swordtails possess a streamlined body, akin to the Southern platy. They feature a wide tailfin, a pointed snout, and an upturned mouth.

The midsection, where the dorsal and pelvic fins appear, is the widest part of their body.

Swordtails exhibit a plethora of color variations. Wild specimens typically have an olive-green base with a brown lateral stripe running through the sword.

However, thanks to cross-breeding, a multitude of unique aesthetic options have emerged, including red, orange, and black morphs, as well as multi-colored and distinct patterned varieties.

Natural Habitat of Swordtail Fish

Swordtails are incredibly adaptable and can thrive in a wide range of environments. In the wild, these freshwater fish inhabit warm streams and rivers abundant with vegetation.

They can be found in various locations across North and Central America, with the highest prevalence in Belize, Guatemala, and Mexico.

Interestingly, Swordtails can survive in virtually any freshwater environment, from shallow mountain creeks to deep rivers.

They can even prosper in brackish estuaries near the coast. This adaptive lifestyle is one of the reasons why Swordtail fish care is such a straightforward task.

Origin and Distribution of Swordtail Fish

Originating from North and Central America, Swordtails belong to the Poeciliidae family. They share a close relation with other common aquarium species like platy and guppy.

Their popularity in the aquarium trade is largely due to their ease of care and breeding, resulting in a wide array of colors and variations.

Swordtail fish are some of the most widely sold in the aquarium trade. They are readily available at most pet stores and are a favorite among breeders.

Thanks to their penchant for cross-breeding and ease of care, many different colors and variations exist, making them a captivating species for display.

Growth, Size & Lifespan of Swordtail Fish

Swordtail fish are considered medium-sized freshwater fish. Males, including the elongated tail, reach an average size of 5.5 inches in length.

Females often grow about an inch larger, making them slightly bigger than their male counterparts.

The growth of Swordtails can be influenced by various factors, including the quality of care provided and their genetic predisposition. With optimal care, these fish can reach their full size within a year.

In terms of lifespan, Swordtails typically live between three to five years.

However, this can vary depending on factors such as the quality of care, genetic predispositions, and overall health. Fish kept in the best and most stable living conditions tend to live longer.

Types of Swordtail Fish

In this section, We will delve into the various types of swordtails, exploring their unique characteristics and variations.

Green Swordtail

The Green Swordtail is the most recognized type of swordtails. It boasts a vibrant green body, often accentuated with a red or orange stripe running along its side.

The males are particularly striking, with a long, sword-like tail fin that can be as long as the body itself. This type of swordtail fish is a common sight in home aquariums and is loved for its bright coloration and active behavior.

Red Swordtail

The Red Swordtail is another popular variety. As the name suggests, this type has a bright red body, which can range from a light orange-red to a deep, fiery red.

The males’ tail fin is typically red or black, creating a stunning contrast against their vibrant bodies. Red Swordtails are a fantastic choice for aquarists looking to add a splash of color to their tanks.

Black Swordtail

The Black Swordtail is a fascinating variety with a dark, almost velvety body. This type is less common than the green and red varieties but is equally striking.

The males’ tail fin is usually black, matching the rest of their body. Black Swordtails are a unique addition to any aquarium, offering a touch of sophistication with their dark coloration.

Other Varieties

In addition to these common types, there are several other varieties of swordtail fish.

These include:

Pineapple Swordtail

The Pineapple Swordtail is a beautiful variety that features a mix of yellow and black colors, reminiscent of a ripe pineapple.

This variety is a real standout in any aquarium due to its unique coloration.

Tuxedo Swordtail

The Tuxedo Swordtail is another interesting variety. It features a two-tone coloration, typically with a darker upper body and a lighter lower body, giving the appearance of a tuxedo—hence its name.

Marigold Swordtail

The Marigold Swordtail is a stunning variety that features a mix of orange and yellow hues, similar to a blooming marigold flower. This variety is a bright and cheerful addition to any aquarium.

In conclusion, swordtail fish come in a variety of types, each with its unique coloration and characteristics.

Whether you prefer the classic Green Swordtail, the vibrant Red Swordtail, or the unique Pineapple Swordtail, there’s a type of swordtail fish to suit every aquarist’s preference.

Swordtail Fish Behavior and Temperament

Swordtail fish are known for their peaceful and sociable nature, making them an excellent choice for community aquariums.

They are active swimmers and tend to stick to the middle and upper parts of the water column. While they are not shoaling species, Swordtail fish enjoy the company of others and often form loose groups.

Male Swordtail fish can exhibit territorial behavior, especially when there are multiple males in the same tank. To maintain harmony, it’s recommended to keep a higher ratio of females to males.

Despite this occasional aggression, Swordtail fish are generally friendly and interact well with other fish species.

Crafting the Perfect Home: Swordtail Fish Tank Setup

Creating a comfortable and stimulating environment for your Swordtail fish is crucial for their health and happiness. Here’s a detailed guide on setting up the perfect tank for your Swordtail fish.

Tank Size

Given their active nature, Swordtail fish require ample space to swim. A minimum tank size of 15 gallons is recommended for a single Swordtail fish.

However, if you plan to keep a group, a 30-gallon tank or larger is ideal.


Swordtail fish aren’t particularly picky about substrate as they spend most of their time in the middle and upper parts of the tank.

However, a substrate that mimics their natural riverbed habitat, such as fine sand or small, smooth gravel, can make them feel more at home.

Decorations and Hiding Spots

Swordtails appreciate a tank that replicates their natural environment. Incorporate live or artificial plants, driftwood, and rock caves to provide shelter and hiding spots.

Plants like Java fern, Anubias, and dwarf hairgrass are excellent choices. Remember to leave plenty of open space for swimming.

Water Parameters

Maintaining the right water parameters is crucial for the health of your Swordtails.

They prefer slightly alkaline water with a pH level between 7.0 and 8.4, a temperature range of 65°F to 82°F, and water hardness between 12 to 35 dGH.

Filtration and Aeration

A high-quality filter is essential to keep the water clean and free from harmful toxins. Swordtail fish also appreciate a moderate current, which can be achieved with a good filtration system.

Additionally, an air pump can be used to ensure adequate oxygen levels in the tank.


Swordtails do not have specific lighting requirements. However, a standard aquarium light that mimics a regular day-night cycle can help regulate their biological rhythms.

Tank Mates

Swordtail fish are peaceful and get along well with most non-aggressive species of similar size.

Suitable tank mates include Platy Fish, Molly Fish, Angelfish, Cory Catfish, Rosy Barbs, Dwarf Gouramis, Neon Tetras, Celestial Pearl Danios, Kuhli Loaches, and Otocinclus.


Swordtail fish are omnivores and thrive on a varied diet. Feed them a combination of nutrient-rich flakes or pellets, algae wafers, and occasional high-protein snacks like brine shrimp, daphnia, and bloodworms.

Juveniles require more protein for growth. Feed your fish two or three small meals a day, providing enough food for them to eat within two minutes.

Swordtail Fish Tank Maintenance

Ensuring a clean and healthy environment is crucial for the well-being of your Swordtais.

Regular tank maintenance not only keeps the water conditions optimal but also helps in early detection and prevention of potential health issues. Here’s a detailed guide on maintaining your Swordtail fish tank.

Regular Water Changes

Regular water changes are essential to maintain the right water parameters and to remove waste, uneaten food, and any chemicals that might have built up over time.

It’s recommended to change 10-20% of the tank water weekly. Always ensure the new water is treated and matches the temperature and pH of the existing tank water to avoid shocking the fish.

Cleaning the Tank and Decorations

Over time, algae and waste can accumulate on the tank walls and decorations. Regular cleaning helps maintain a healthy environment for your Swordtails.

Use an algae scraper or pad to clean the tank walls and a gravel vacuum to clean the substrate. Decorations can be cleaned with a soft brush under running water. Avoid using soap or detergents as they can be harmful to fish.

Filter Maintenance

The filter plays a crucial role in maintaining water quality by removing waste and harmful chemicals. Regular maintenance ensures its efficient operation.

Rinse the filter media in the removed tank water during water changes to remove debris without killing beneficial bacteria. Replace the media as per the manufacturer’s instructions.

Monitor Fish Health

Regular observation of your Swordtails can help detect any signs of illness early. Look out for changes in behavior, eating habits, or appearance.

Common health issues include Ich, a contagious ectoparasite, and fungal infections. Regular monitoring of tank conditions and water changes can help prevent these diseases.

In conclusion, regular tank maintenance is key to keeping your Swordtail fish healthy and happy. By following these guidelines, you can ensure a clean and stimulating environment for your aquatic pets.

Acclimating Swordtail Fish

Introducing Swordtails to a new aquarium requires careful acclimation to ensure they adapt to their new environment without stress.

Start by floating the bag containing the fish in the aquarium for about 15 minutes to equalize the temperature.

Next, gradually add small amounts of tank water to the bag every 10 minutes for about an hour. This process helps the fish adjust to the water parameters of the new tank.

Once acclimated, gently release the fish into the tank. Avoid adding the bag water to the aquarium to prevent potential contamination.

Swordtail Fish: Diet and Feeding

Swordtail fish are omnivores and require a balanced diet of both plant-based and protein-rich foods.

Here’s a detailed guide on feeding your Swordtail fish.

Commercial Fish Food

Commercially available fish food forms the staple of your Swordtail fish’s diet. Opt for high-quality flakes or pellets that are nutrient-rich. These foods are formulated to provide a balanced diet and support the overall health of your fish.

Algae Wafers

Swordtails enjoy plant-based food, and algae wafers are an excellent choice. They not only provide necessary nutrients but also help keep your fish’s digestive system healthy.

Live, Frozen, and Freeze-dried Foods

In addition to commercial food, Swordtails benefit from the occasional inclusion of live, frozen, or freeze-dried foods. These can include:

  • Brine shrimp

  • Daphnia

  • Bloodworms

These foods are high in protein and help in enhancing the color and vitality of your fish.

Feeding Schedule

Swordtails should be fed two to three times a day. Each feeding should last about two minutes, providing just enough food that they can consume in this time.

Overfeeding can lead to poor water quality and health issues. Any uneaten food should be removed promptly.

Juvenile Diet

Juvenile Swordtail fish require a diet rich in protein for growth. In addition to the regular diet, provide them with high-protein snacks more frequently.

In conclusion, a varied and balanced diet is key to keeping your Swordtail fish healthy and vibrant. By following these guidelines, you can ensure your fish receive the necessary nutrients they need to thrive.

Swordtail Fish Tank Mates and Those to Avoid

Swordtail fish are peaceful and sociable, making them excellent community fish. However, choosing the right tank mates is crucial to maintain harmony and prevent stress.

Here’s a detailed guide on suitable tank mates and those to avoid.

Suitable Tank Mates for Swordtail Fish

Swordtail fish get along well with most non-aggressive species of similar size.

Here are some suitable tank mates:

  1. Platy Fish: Like Swordtail fish, Platies are peaceful and easy to care for, making them an excellent choice.

  2. Molly Fish: Mollies are sociable and non-aggressive, making them compatible with Swordtail fish.

  3. Angelfish: Despite their size, Angelfish are generally peaceful and can coexist with Swordtail fish.

  4. Cory Catfish: These bottom dwellers are peaceful and will not compete with Swordtail fish for space.

  5. Rosy Barbs: Rosy Barbs are active and peaceful, making them a good match for Swordtail fish.

  6. Dwarf Gouramis: These calm and colorful fish can add diversity to your tank without causing stress to your Swordtail fish.

  7. Neon Tetras: These small, peaceful fish are a popular choice for community tanks.

  8. Celestial Pearl Danios: Known for their peaceful nature, these fish can coexist well with Swordtail fish.

Tank Mates to Avoid

Avoid aggressive or boisterous fish that can stress or harm your Swordtail fish.

Here are some species to avoid:

  1. Cichlids: Many Cichlids are aggressive and can bully or harm Swordtail fish.

  2. Tiger Barbs: Known for their fin-nipping behavior, Tiger Barbs can stress and harm Swordtail fish.

  3. Bettas: Male Bettas are territorial and can show aggression towards Swordtail fish.

  4. Red Tail Sharks: These fish are known to be aggressive and territorial, making them unsuitable tank mates.

  5. Oscar Fish: Oscars are large and aggressive, posing a threat to Swordtail fish.

Breeding Swordtail Fish and Fry Care

Breeding Swordtail fish is a rewarding experience. They are livebearers and can spawn in captivity with minimal intervention.

Here’s a detailed guide on breeding Swordtail fish and caring for the fry.

Breeding Process

  1. Set Up a Breeding Tank: A separate breeding tank with fine-leaf plants and a temperature around 80 degrees can increase the survival rate of the fry.

  2. Condition the Breeding Pair: Feed your breeding pair high-protein foods to prepare them for spawning.

  3. Spawning: When ready, the fish will spawn, and the female will start to swell with eggs. A visible gravid spot will develop.

Fry Care

  1. Separate the Adults: After birth, remove the adults to protect the fry, as Swordtail fish exhibit no parental instincts.

  2. Feeding the Fry: Fish fry are too small to eat standard flakes or pellets. Provide powdered fish food, infusoria, or freshly hatched brine shrimp until they are big enough to eat traditional foods.

  3. Monitor the Fry: Keep a close eye on the fry and monitor their growth. Regular water changes and maintaining optimal water parameters are crucial during this stage.

In conclusion, with the right tank mates and proper care, your Swordtail fish can thrive and even breed in your aquarium.

By following these guidelines, you can ensure a peaceful and stimulating environment for your Swordtail fish.

Recognizing Distress: Signs of Stress in Swordtail Fish

Just like any other living creature, Swordtail fish can experience stress, which can lead to health issues if not addressed promptly.

Signs of stress in Swordtail fish include:

  • Changes in Behavior: This could include loss of appetite, lethargy, or unusual aggression.

  • Changes in Appearance: Look out for faded colors, clamped fins, or visible spots or patches on the body.

  • Erratic Swimming: This could include swimming near the surface, at the bottom, or hiding more than usual.

If you notice any of these signs, it’s crucial to identify and address the cause of the stress, which could be poor water quality, inappropriate tank mates, or illness.

Common Health Issues and Treatments for Swordtail Fish

Swordtail fish are generally hardy, but they can still suffer from common fish diseases.

Here are a few and their treatments:

  • Ich: This is a common parasitic disease that presents as white spots on the fish’s body. It can be treated with over-the-counter medications and by raising the tank temperature slightly.

  • Fungal Infections: These often appear as fluffy growths on the fish’s body. They can be treated with antifungal medications.

  • Fin Rot: This bacterial disease causes the fins to fray and rot away. It can be treated with antibacterial medications.

In all cases, maintaining good water quality and promptly isolating sick fish can help prevent the spread of disease.

Additional Tips for a Healthy Aquarium

  • Regular Maintenance: Regular water changes and tank cleaning are crucial for maintaining a healthy environment.

  • Monitor Water Parameters: Keep a close eye on the water temperature, pH, and hardness to ensure they remain within the appropriate range for Swordtail fish.

  • Balanced Diet: Feed your fish a varied and balanced diet to keep them healthy and vibrant.

  • Quarantine New Fish: Always quarantine new fish before introducing them to your main tank to prevent the spread of disease.

Should You Get a Swordtail Fish for Your Aquarium?

Swordtail fish are a fantastic addition to any freshwater aquarium due to their vibrant colors, peaceful nature, and ease of care.

They are suitable for both beginners and experienced aquarists. However, they do require a certain level of care, including a spacious tank, regular maintenance, and a balanced diet.

If you can provide these, Swordtail fish can make a rewarding and beautiful addition to your aquarium.

Conservation Status of Swordtail Fish

Swordtail fish are not currently listed as endangered or threatened. They are widespread in their native habitats in North and Central America, and their populations are stable.

However, like all wildlife, they can be affected by habitat loss and pollution. Responsible pet ownership and sustainable fishing practices can help ensure their continued survival.

Availability & Pricing of Swordtail Fish

Swordtail fish are widely available in pet stores and online due to their popularity in the aquarium trade.

They are also frequently bred in captivity, which contributes to their availability. Prices can vary depending on the size, color, and variety of the fish, but they are generally affordable, making them a great choice for both novice and experienced aquarists.

Frequently Asked Questions About Swordtail Fish

Q: How long do Swordtail fish live?

A: With proper care, Swordtail fish can live for 3 to 5 years in captivity.

Q: What do Swordtail fish eat?

A: Swordtail fish are omnivores and thrive on a varied diet of commercial fish food, algae wafers, and occasional high-protein snacks like brine shrimp and bloodworms.

Q: Can Swordtail fish live with other fish?

A: Yes, Swordtail fish are peaceful and sociable, making them excellent community fish. They get along well with most non-aggressive species of similar size.

Q: How do you breed Swordtail fish?

A: Swordtail fish are livebearers and can spawn in captivity with minimal intervention. A separate breeding tank with fine-leaf plants and a temperature around 80 degrees can increase the survival rate of the fry.


Swordtails are a delightful addition to any freshwater aquarium. Their vibrant colors, peaceful nature, and ease of care make them a favorite among aquarists.

Whether you’re a beginner or an experienced fish keeper, Swordtails offer a rewarding and engaging pet ownership experience.

With the right care and environment, these beautiful fish can thrive and bring joy to your home aquarium.