Flagtail Catfish: A Comprehensive Care Guide (2024)

Dianema urostriatum close up profile
Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: October 3, 2023
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Flagtail catfish, admired for their distinctive flag-like tails and vibrant colors, are favored in freshwater aquariums. This guide, suitable for aquarists of all levels, provides essential information for the care and thriving of these captivating fish, making them a wonderful addition to your collection. Dive into the world of flagtail catfish care with confidence.

Article Summary

  • Flagtail catfish, scientifically known as Dianema urostriatum, are native to South America, particularly the Amazon River basin.
  • They have an elongated body with a distinctive flag-like tail fin and typically reach 4 to 6 inches in length, with a lifespan of 8 to 10 years in proper care.
  • Proper care involves regular water changes, clean and well-aerated water, and a balanced diet of sinking pellets, flakes, frozen foods, and vegetables.

Species Overview

The flagtail catfish, scientifically known as Dianema urostriatum, is a popular freshwater fish catfish species that is native to the rivers and streams of South America. They are commonly found in the Amazon River basin and its tributaries, including countries like Brazil, Colombia, Venezuela, and other parts of the Amazon rainforest.

These catfish have an elongated body with a flattened belly, which is typical of most catfish species. What sets them apart is their distinct flag-like tail fin that gives them their name. Their body coloration usually ranges from brown to grayish, often adorned with dark spots along their sides. The pectoral fins of flagtail catfish have sharp spines that serve as a defense mechanism.

In terms of size, flagtail catfish typically reach about 4 to 6 inches (10 to 15 centimeters) in length. While they generally stay within this range, some individuals may grow slightly larger, reaching up to 10 inches in length. These fish reach their adult size within a year or two.

One remarkable aspect of flagtail catfish is their relatively long lifespan for aquarium fish. They can live for 8 to 10 years or even more when provided with proper care and suitable tank conditions.

Habitat and Tank Conditions

To ensure the well-being of your flagtail catfish, it is crucial to create a suitable habitat in your aquarium. Consider the following factors when setting up their tank:

Tank Size and Set Up

Flagtail catfish (Dianema urostriatum) originate from the Amazon River basin in South America. These active swimmers appreciate ample space to roam around. For a small group of flagtail catfish, it is recommended to have a tank size of at least 20 to 30 gallons. This will provide them with enough room to move comfortably.

To mimic their natural habitat in the Amazon River Basin, make sure to include hiding spots and areas with dense vegetation in the tank. Flagtail catfish are often found in slow-moving or still waters with plant cover, so replicate this environment as closely as possible.

flagtail catfish in light substrate

Water Parameters

Maintaining appropriate water conditions is essential for the health of your Dianema urostriatum. Keep the water temperature between 72°F and 78°F (22°C to 26°C) since this range aligns with their preferred conditions. Aim for a slightly acidic to neutral pH level, ideally around 6.0 to 7.0. Soft to moderately hard water with a dGH (degree of general hardness) between 5 and 12 is suitable for these fish.

Substrate and Decor

Flagtail catfish, scientifically known as Dianema urostriatum, thrive in heavily planted tanks that offer plenty of hiding spots. Use fine-gravel or sand substrate to resemble their natural riverbed habitat. Incorporate driftwood, rocks, and live plants into the tank decor for added complexity.

By providing an environment that closely resembles their native habitat of the Amazon River Basin, you can ensure that your flagtail catfish feel secure and comfortable in their new home.

Tankmates and Temperament

It’s important to consider their behavior and temperament. These fish are generally peaceful fish but can become territorial during breeding season. They are active swimmers and may spend time exploring the tank.

Compatible Tank Mates

Flagtail catfish, or Dianema urostriatum, can coexist with other peaceful community fish such as tetras, rasboras, dwarf cichlids, and other small catfish species like Corydoras catfish. It’s best to choose tank mates that share similar water parameter requirements. Bottom-dwelling fish that occupy different levels of the tank can also make suitable companions for flagtail catfish.

Tank Mates to Avoid

It’s crucial to avoid keeping flagtail catfish with aggressive or fin-nipping species. Larger, aggressive species like are cichlids should be avoided as well since they may stress or injure the flagtail catfish. Be cautious with very small fish that might be seen as potential prey, as flagtail catfish may occasionally attempt to eat very small tank mates.

Flagtail Catfish Care

To ensure the well-being of your flagtail catfish, there are a few essential care recommendations to keep in mind. Regular water changes are crucial as they help maintain good water quality for these fish. It is important to provide them with clean and well-aerated water, which can be achieved through proper filtration.

Food and Diet

Flagtail catfish, scientifically known as Dianema urostriatum, are omnivorous and will readily accept a variety of foods. To ensure a balanced and varied diet, it is recommended to feed them high-quality sinking pellets or flakes. Incorporating frozen foods or live foods like bloodworms, brine shrimp, and daphnia can enhance their nutritional intake. Don’t forget about veggies! Including blanched spinach or zucchini in their diet can provide additional nutrients.

Feeding your flagtail catfish 2-3 times a day is ideal. However, be mindful of providing only what they can consume within a few minutes to prevent overfeeding and subsequent water pollution.

Fish Food
Fish Food

Common Disease Prevention

While flagtail catfish are relatively hardy, they can still be susceptible to common aquarium diseases such as ich (white spot disease) and bacterial infections. To minimize the risk of introducing diseases into the tank, it is advisable to quarantine new fish before adding them to the main tank.

Keeping an eye on their overall health is important. Be vigilant for any signs of disease or stress such as loss of appetite, abnormal swimming behavior, or visible physical abnormalities. Prompt action should be taken if any issues arise by consulting with a knowledgeable aquarium professional or veterinarian.

By following these care recommendations and providing a suitable environment for your flagtail catfish, you can ensure that they thrive happily in your aquarium.

Breeding the Flagtail Catfish

Breeding flagtail catfish (Dianema urostriatum) in captivity can be quite a challenge due to their specific requirements. To successfully breed these fascinating creatures, a separate breeding tank with suitable spawning sites is necessary. It’s important to maintain optimal water conditions and provide proper nutrition during this process.

Recommended Tank Set Up

For breeding flagtail catfish, it’s essential to have a well-prepared tank that meets their needs. Here are some key considerations:

Spawning Sites: Provide fine-gravel substrate with hiding places like caves or PVC pipes where the fish can lay their eggs.

Water Temperature: Maintain slightly warmer water conditions, around 78-82°F or 26-28°C, to simulate the rainy season when they naturally breed.

Water Quality: Ensure clean and well-filtered water with suitable pH levels (around 6.5-7) for optimal breeding conditions.

pair of flagtail catfish

Breeding Process

Flagtail catfish are egg layers and go through a specific breeding process. The male and female will engage in a courtship ritual, often swimming closely together. The female will carefully choose a hiding spot within the tank to lay her eggs. The male fertilizes the eggs immediately after they are laid, and both parents diligently guard the nest.

After a few days, the eggs hatch into fry, which are tiny versions of the adult fish. It’s crucial to remove the adult catfish from the breeding tank promptly to prevent them from eating the fry.

Fry Care

Caring for flagtail catfish fry requires attention and specialized feeding. Initially, feed them infusoria or newly hatched brine shrimp, which are small enough for their delicate mouths.

As the fry grow, introduce them to larger foods like finely crushed flakes or powdered fry food. Frequent water changes and careful monitoring of water quality are essential for the healthy development of the fry.

Breeding flagtail catfish can be a rewarding experience with proper care and attention. By creating an ideal environment and providing adequate nutrition, you can witness the incredible journey from egg to fry. Happy breeding!

Frequently Asked Questions

How big do flagtail catfish get?

Flagtail Catfish (Dianema urostriatum) typically reach sizes of about 4 to 6 inches (10 to 15 centimeters) when kept in aquariums. The size can vary based on factors such as diet and tank conditions.

Are flagtail fish aggressive?

Flagtail Catfish are generally peaceful in temperament. They are well-suited for community aquariums and are not considered aggressive. However, like many fish species, they may exhibit territorial behavior, especially during breeding or in certain situations.

What do flagtail fish eat?

Flagtail Catfish have an omnivorous diet. They readily accept various types of food, including high-quality sinking pellets or flakes, live or frozen foods like bloodworms and brine shrimp, and even blanched vegetables such as spinach or zucchini. Providing a balanced and varied diet consisting of protein and vegetables is essential for their health.

Do flagtail fish eat algae?

While Flagtail Catfish may occasionally nibble on algae in the aquarium, they are not primarily algae-eating fish. They should not be relied upon as the primary means of controlling algae growth. Offering them a varied diet that includes specialized fish food is important.

Do flagtails eat other fish?

Flagtail Catfish (Dianema urostriatum) are not known for being predatory or aggressive towards other fish. They are peaceful and generally coexist well with a variety of tank mates, as long as the tank conditions are suitable and there are no significant size or aggression disparities.

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