The Marigold Swordtail – All You Need To Know - "Marigold Swordtails" by Eric F Savage is licensed under CC BY-SA 2.0.
The Marigold Swordtail – All You Need To Know - "Marigold Swordtails" by Eric F Savage is licensed under CC BY-SA 2.0.


The Marigold swordtail fish is a captivating and popular freshwater aquarium fish cherished by aquarists for its striking appearance and ease of care. With its radiant, marigold-colored body and unique sword-like tail, this species adds a burst of color and vibrancy to any aquarium. Creating the perfect environment for Marigold swordtails is not only essential for showcasing their beauty but also for ensuring their well-being and breeding potential. In this guide, we will explore the ideal setup, tank mates, feeding, and care tips to help you create a thriving aquatic habitat for these remarkable fish. Whether you’re a seasoned hobbyist or a newcomer to the world of aquarium keeping, this comprehensive guide will assist you in successfully caring for Marigold swordtails and appreciating their charm in your aquatic sanctuary.

Appearance and Behavior of Marigold Swordtails

Marigold swordtails are a vibrant and popular species of freshwater aquarium fish. They are a variety of swordtail fish, which are named for the distinctive elongated lower lobe of the male’s tail fin, resembling a sword.


  • Coloration: Marigold swordtails are known for their striking and vibrant coloration, which is one of the key reasons for their popularity in the aquarium hobby. They are predominantly golden-yellow, with a marigold or sunburst-like hue that covers most of their bodies. The males tend to have a more intense coloration, while the females are somewhat less vibrant.
  • Body Shape: These fish have a typical elongated body shape, with a streamlined appearance. The males have the characteristic sword-shaped tail fin, which is typically elongated and can be as long as half the length of their body.
  • Size: Marigold swordtails are relatively small fish, with males reaching around 4-5 inches (10-12 cm) in length, while females are slightly larger, reaching up to 5-6 inches (12-15 cm).


  • Social and Peaceful: Marigold swordtails are generally peaceful and social fish, making them suitable for community aquariums. They are known for their compatibility with a wide range of other peaceful freshwater fish species. However, it’s essential to avoid aggressive tankmates that may harass or nip at their long tails.
  • Active Swimmers: These fish are active swimmers and enjoy exploring their environment. They often occupy the middle to upper water levels of the aquarium and appreciate having plenty of open swimming space.
  • Reproductive Behavior: Marigold swordtail fish are livebearers, which means they give birth to live fry rather than laying eggs. Breeding these fish is relatively straightforward, and they can produce numerous fry in a well-maintained aquarium. They exhibit courtship behavior, with males displaying their vivid colors and flashing their sword-like tails to attract females.
  • Hardy and Easy to Care For: Marigold swordtails are known for their hardy nature and adaptability to a range of water conditions. They can thrive in a well-maintained aquarium with stable water parameters, including a temperature range of 72-82°F (22-28°C) and a pH level between 7.0 and 8.0.

Marigold swordtails are a visually stunning and relatively easy-to-care-for species of freshwater aquarium fish. Their vivid marigold coloration and sword-like tails make them an attractive addition to community tanks. They are social and peaceful fish, known for their active behavior and straightforward breeding habits, making them a favorite among aquarium enthusiasts.

Tank Mates For Your Marigold Swordtail Fish

When selecting tank mates for Marigold swordtails it’s essential to choose fish that are peaceful, compatible in terms of water requirements, and won’t harass or outcompete the swordtails. Here are some suitable tank mates for your Marigold swordtail:

  • Other livebearers: Marigold swordtails are compatible with other livebearer species such as guppies, platies, and mollies. These fish share similar water parameter requirements and reproductive habits.
  • Tetras: Peaceful tetras like neon tetras, cardinal tetras, and harlequin rasboras can coexist with Marigold swordtails. They add color and activity to the aquarium without being aggressive.
  • Corydoras catfish: Corydoras species, such as the bronze corydoras or panda corydoras, are bottom-dwelling, peaceful fish that can help keep the tank clean. They won’t bother your Marigold swordtails.
  • Danios: Zebra danios and pearl danios are active swimmers that generally get along with Marigold swordtails. They prefer similar water conditions and swimming patterns.
  • Small rainbowfish: Species like the rainbowfish are peaceful and can share the same water parameters as Marigold swordtails.
  • Rasboras: Rasboras like the chili rasbora or lambchop rasbora are small, peaceful fish that won’t compete with Marigold swordtails for territory.
  • Gouramis: Dwarf gouramis are generally compatible, as long as the tank is of sufficient size. Avoid larger or more aggressive gouramis that may harass Marigold swordtails.
  • Bristlenose plecos: Bristlenose plecos is a good choice for an algae-eating bottom-dweller. They are peaceful and help maintain water quality.
  • Snails and shrimp: Amano shrimp or various snail species like Nerite snails and Malaysian trumpet snails can help with algae control and won’t pose a threat to Marigold swordtail fish.

Remember that while Marigold swordtails are generally peaceful, individual temperament can vary. It’s always a good idea to monitor their interactions when introducing new tank mates and have a backup plan in case any fish become aggressive or overly territorial. Also, provide plenty of hiding places and ample swimming space to reduce stress and potential conflicts in the aquarium. Additionally, ensure that the tank size is appropriate for the combined bio-load of all the fish to maintain good water quality.

The Marigold Swordtail – All You Need To Know - "Marigold Swordtails" by Eric F Savage is licensed under CC BY-SA 2.0.
The Marigold Swordtail – All You Need To Know – “Marigold Swordtails” by Eric F Savage is licensed under CC BY-SA 2.0.

Aquarium Setup

Setting up an aquarium for Marigold swordtails involves creating an environment that mimics their natural habitat while providing a safe and comfortable space for them to thrive. Here are the key steps to set up an ideal aquarium for Marigold swordtail fish:

  • Tank Size: Marigold swordtails are active swimmers, so a tank size of at least 20 gallons (75 liters) for a small group is recommended. Larger tanks are better, as they provide more swimming space and help maintain stable water parameters.
  • Water Parameters: Maintain a water temperature between 72-82°F (22-28°C). Keep the pH level in the range of 7.0 to 8.0.
  • Filtration: Use a good-quality aquarium filter to maintain water quality. Swordtails are sensitive to ammonia and nitrite, so an efficient filtration system is crucial.
  • Substrate: A fine gravel or sand substrate is ideal. Marigold swordtails like to sift through the substrate in search of food, and a smooth substrate prevents injury to their sensitive mouths.
  • Decor and Plants: Provide plenty of hiding spots and areas for exploration using driftwood, rocks, and artificial or live plants. Swordtails appreciate dense plantings, such as Vallisneria, Java Fern, and Amazon Sword, as they offer hiding places and aid in water quality.
  • Lighting: Moderate to low-intensity lighting is sufficient for Marigold swordtails. It’s essential to provide a day-night cycle with a timer for about 10-12 hours of light per day.
  • Aeration: Swordtails appreciate good water circulation and aeration, which can be achieved with air stones or adjustable flow from the filter.
  • Maintenance: Regular water changes are essential to maintain water quality. A 25% water change every 2-4 weeks is a good starting point, but the frequency may vary based on your tank’s specific conditions.
  • Tank Mates: Choose compatible tank mates, as discussed earlier. Ensure that the tank is not overcrowded to prevent territorial issues.
  • Feeding: Marigold swordtails are omnivorous. Provide them with a balanced diet of high-quality flake or pellet food supplemented with live or frozen options like brine shrimp, daphnia, and vegetable matter. Feed them once or twice a day, only what they can consume in a few minutes.

Remember that Marigold swordtails are livebearers and can reproduce readily in captivity. If you intend to breed them, provide dense plant cover for fry to hide in, as the adults and other fish may eat the offspring.

By following these guidelines, you can create a well-maintained and suitable aquariumyou’re your Marigold swordtail, ensuring their health and well-being.


In conclusion, setting up an aquarium for Marigold swordtails requires careful consideration of their specific needs and preferences. By providing the right tank size, water parameters, filtration, substrate, decor, and suitable tank mates, you can create an environment that closely resembles their natural habitat and promotes their well-being.

Marigold swordtail fish are known for their vibrant colors, active nature, and ease of care, making them a popular choice among freshwater aquarium enthusiasts. Maintaining a well-maintained tank with proper feeding, water quality testing, and regular maintenance will help ensure the health and longevity of these beautiful fish.

With the right setup and attention to their requirements, Marigold swordtails can thrive, exhibit their natural behaviors, and even reproduce in a home aquarium. Creating a comfortable and aesthetically pleasing habitat for these fish can be a rewarding experience for both novice and experienced aquarists, allowing you to enjoy the beauty and charm of this captivating species.