Redtail Catfish – Care, Size, Tank Mates, Food & Full Details!

The redtail catfish, or Phractocephalus hemioliopterus, is a strikingly large freshwater fish native to northern South American countries such as Colombia, Brazil, Peru, Venezuela, Ecuador, Guyana, and Bolivia.

Its natural habitat encompasses freshwater river basins (mainly Amazon and Orinoco), streams, and lakes.

It has an eclectic diet, consuming whatever comes its way, and it is revered in its native regions due to its imposing size and the folklore surrounding its supposed aggression.

Understanding and appreciating the redtail catfish requires careful study and attention to detail. This massive freshwater fish species poses an intriguing challenge for seasoned aquarists and demands a commitment to their particular care needs.

Our comprehensive guide aims to offer a clear picture of what it truly means to raise and care for a redtail catfish.

Quick Stats About Redtail Catfish

Scientific Name Phractocephalus hemioliopterus
Family Pimelodidae
Common Names Redtail catfish; redtail fish
Range and habitat Brazil, Colombia
Size 1.8 m (5 ft 11 in)
Lifespan 15 years
Ease of keeping Easy
Minimum tank size 220 gallons and more
Temperament Predator
Diet Omnivorous
Temperature 72-78 °F (22-26 °C)
pH 6.0-7.5
Water hardness 5-20 dGH

Exploring the world of freshwater aquariums introduces you to an impressive variety of aquatic life. Among them, the redtail catfish holds a prominent position due to its unique appearance and size.

Dive with us into the captivating universe of the redtail catfish as we discuss its appearance, natural habitat, origin, and other essential factors like growth, size, and lifespan.

Appearance of Redtail Catfish

The redtail catfish or Phractocephalus hemioliopterus is a remarkable freshwater species owing to its imposing presence.

The classic catfish silhouette graced with a couple of significant features makes the redtail catfish hard to miss, even in a crowded aquarium.

Its most distinguishing feature, as the name implies, is the vibrant red tail, contrasting sharply with the dark grey body.

This scarlet hue often extends to the upper part of the dorsal fin, creating a striking visual appeal.

A close look at this impressive fish reveals a body stippled with faint dots, covering the dark grey expanse.

A stark white underbelly extends from the underside of the head to where the pectoral fins start, continuing to the base of the caudal fins.

The facial structure of the redtail catfish is characterized by large barbels, mimicking the look of whiskers.

These barbels jut out straight, lending a sense of assertiveness to its look, regardless of whether it’s in motion or at rest.

Natural Habitat of Redtail Catfish

Understanding the natural habitat of redtail catfish is instrumental for any aquarist wishing to recreate similar conditions in a home aquarium.

Native to the north-most countries of South America, redtail catfish inhabit freshwater river basins, streams, and lakes, displaying a remarkable adaptability to diverse aquatic environments.

The Amazon and Orinoco river basins are the primary playgrounds for these large fish, where they can hunt for a variety of prey.

Not known for being picky eaters, they feed on anything they can get their barbels on, marking their presence as formidable predators in these water bodies.

Origin and Distribution of Redtail Catfish

The geographic distribution of redtail catfish covers a considerable expanse, spanning countries like Colombia, Brazil, Peru, Venezuela, Ecuador, Guyana, and Bolivia.

These areas teem with folklore about the size and aggressive tendencies of redtail catfish, cultivating a profound respect for these creatures among local populations.

Growth, Size & Lifespan of Redtail Catfish

Dwelling into the aspects of growth, size, and lifespan of redtail catfish helps us appreciate its true magnificence. Captivity sees these creatures reaching an average length of about 3-4 feet.

However, their counterparts in the wild can grow up to 5 feet, underlining the vast difference in the growth rate across different environments.

A crucial point to note is that their size necessitates a large enough tank, ensuring the fish’s comfort and facilitating its natural behavior.

Keeping these fish in smaller tanks at a young age could stunt their growth, but they can still attain a considerable size, around 3 feet, under such circumstances.

When it comes to lifespan, the redtail catfish enjoys a reasonably long life, with an average lifespan of 15 years in captivity.

However, subpar care or inadequate living conditions can significantly shorten this lifespan.

In conclusion, the redtail catfish’s grandeur demands more than just an appreciative glance.

It requires a detailed understanding and careful attention to its needs, ensuring a healthy and comfortable life for this majestic creature.

Redtail Catfish: Behavior and Temperament

The behavior and temperament of the redtail catfish mirror its large size and striking presence. Known for their active and curious nature, these fish are always on the move, exploring their surroundings.

Despite their size, they are surprisingly gentle and often display a friendly demeanor, especially in a well-managed tank environment.

However, the predatory instincts of the redtail catfish shouldn’t be underestimated. In the wild, they are opportunistic hunters, ready to consume any animal or fish small enough to fit into their large mouths.

This trait often translates to a robust feeding response in a tank environment as well.

Keep in mind that due to their active nature and large size, redtail catfish can become stressed in confined spaces, resulting in erratic behavior.

Giving them ample space and replicating their natural environment can help ensure a healthy, calm demeanor.

Redtail Catfish Tank Setup

Setting up a perfect habitat for your redtail catfish is an art that requires both knowledge and patience.

The following sections delve into the specifics of creating a conducive environment for these magnificent creatures.

Tank Size

Redtail catfish are large, fast-growing fish. Given this, they require a spacious tank to accommodate their growth and active nature. As a general rule, the minimum recommended tank size for an adult redtail catfish is 1000 gallons.

However, if you’re starting with a younger catfish, a 250-gallon tank will suffice initially. Remember to upgrade the tank as your fish grows to ensure its comfort and health.


When choosing a substrate for your redtail catfish tank, sand proves to be an excellent choice. It is soft, which reduces the risk of the catfish hurting itself as it roams around, and mimics their natural Amazon river bed habitat.

Decorations and Hiding Spots

Redtail catfish appreciate some form of cover to replicate the conditions of their natural habitat. Large rocks and driftwood can serve as ideal hiding spots. However, avoid sharp decorations as they may harm your fish.

Water Parameters

Maintaining optimal water conditions is crucial to your catfish’s health. Redtail catfish prefer a pH range of 6.0 – 7.5 and a temperature between 68°F (20°C) and 79°F (26°C). Regular water testing is a must to ensure these conditions are consistently met.

Filtration and Aeration

Given the large size and dietary needs of redtail catfish, a robust filtration system is necessary to maintain clean water. Similarly, aeration is crucial as these fish require high oxygen levels. A combination of external filters and air stones usually serves these needs effectively.


Redtail catfish are not overly sensitive to light, but a moderate level of lighting that mimics natural conditions will keep your fish most comfortable. Using a timer to simulate a day and night cycle can help create a balanced environment.

Tank Mates

When it comes to tank mates, remember the predatory nature of the redtail catfish. They can live peacefully with other large, non-aggressive fish species. However, smaller fish are often seen as food and may not last long.


Redtail catfish are carnivorous and require a high-protein diet. They happily eat sinking catfish pellets, live foods, and frozen foods like shrimp, mussels, and fish fillets. Always ensure their food is proportionate to their size to maintain their health.

Tank Maintenance for Your Redtail Catfish

Creating a conducive home for your redtail catfish goes beyond initial setup. Regular maintenance is the key to a healthy and happy pet.

Let’s delve into the key aspects of tank maintenance for redtail catfish:

Regular Water Changes

Keeping the water clean is vital for your redtail catfish’s well-being. Regular water changes help remove waste and prevent the buildup of harmful chemicals.

As a rule of thumb, change 10-20% of the tank water weekly. Remember, new water should match the temperature and pH of the existing tank water to avoid shocking your catfish.

Cleaning the Tank and Decorations

Over time, algae and other wastes can accumulate on the tank’s walls and decorations. Cleaning these not only keeps your tank looking fresh but also prevents harmful bacterial growth.

Use a soft algae scraper for the tank walls and a toothbrush for the decorations. Avoid using harsh detergents or chemicals, as they can be harmful to your catfish.

Filter Maintenance

The filter plays a vital role in maintaining the water quality in your catfish tank. Hence, it requires regular attention. Check the filter media weekly and replace it if it’s clogged or damaged.

The internal parts should also be cleaned monthly to ensure efficient operation. Always follow the manufacturer’s instructions when servicing your filter.

Monitor Fish Health

Regularly observing your redtail catfish can help detect health problems early. Check for changes in behavior, eating habits, or appearance. If you notice anything unusual, it’s advisable to consult a fish health expert.

Keeping a close eye on your pet not only ensures its health but also gives you a deeper understanding of its habits and needs.

To conclude, maintaining a tank for your redtail catfish is a rewarding task that requires regular effort. With the right care, your redtail catfish will thrive, providing you with an engaging and fulfilling pet-keeping experience.

Acclimating Redtail Catfish

Bringing a redtail catfish into a new environment requires a gentle and thoughtful process of acclimation.

Here’s how to acclimate your new pet effectively:

Start by floating the bag containing your catfish in your aquarium for 15-20 minutes. This allows the water in the bag to match the tank’s temperature, reducing thermal shock.

Next, gradually mix a little of your tank’s water into the bag every five minutes. This slow introduction helps your fish adjust to the new water conditions, such as pH and hardness.

Finally, after about an hour of slow acclimation, gently release your redtail catfish into the tank. Remember, avoid using any water from the bag, as it could contain contaminants or diseases.

Your redtail catfish is now ready to explore its new home!

Redtail Catfish Diet and Feeding

Redtail catfish have a wide-ranging diet, and understanding their dietary needs will help keep them healthy and vibrant.

Here’s what you need to know:

Variety is Key

Redtail catfish are omnivorous, so a balanced diet should include both plant and animal matter.

Foods can include:

  • Commercial fish pellets: These provide essential nutrients and should form the base of your catfish’s diet.

  • Fresh or frozen foods: Items like shrimps, earthworms, and peas offer variety and extra nutrients.

  • Live foods: Although not always necessary, live foods like feeder fish can stimulate your catfish’s natural hunting instincts.

Feeding Guidelines

Redtail catfish are not picky eaters, but there are a few guidelines you should follow:

  • Feed juvenile redtails 2-3 times a day, reducing to once a day as they grow.

  • Monitor your fish during feeding. They should consume their food within a few minutes. If food is left uneaten, it can decay and harm water quality.

  • As redtail catfish grow quite large, ensure their food is appropriately sized. Larger food items can encourage natural hunting behaviors.

Observing Eating Habits

Always monitor your redtail catfish’s eating habits. Changes in appetite can signal health issues. A healthy redtail catfish should be eager to eat and display energetic behavior around feeding times. A well-fed redtail catfish is a happy and healthy one!

To conclude, a varied diet and careful observation of eating habits are crucial for the well-being of your redtail catfish.

Your commitment to its dietary needs will lead to a thriving and interactive aquatic pet.

Redtail Catfish Tank Mates

Selecting suitable tank mates for your redtail catfish is a crucial part of their care. Given their size and temperament, not all aquatic creatures make a good match.

Given their large size, redtail catfish can live harmoniously with a variety of similarly-sized, peaceful fish.

Here are some options:

  1. Oscar Fish: These large cichlids are hardy and can match the redtail’s size as they grow.

  2. Arowana: These fish are large, active, and can cohabit well with redtails.

  3. Pacu: Pacus are peaceful and can grow to a size that’s safe with redtails.

  4. Giant Gourami: These gentle giants can hold their own with a redtail.

  5. Black Ghost Knife Fish: Known for their unique shape and peaceful nature, these fish can live harmoniously with redtail catfish.

Tank Mates to Avoid

Avoid smaller species that could become prey for the redtail catfish. Moreover, aggressive species can cause stress and even harm.

Here are some species to avoid:

  1. Small Tetras: Their size makes them easy prey for redtails.

  2. Guppies: Despite their popularity, guppies are far too small to house with redtails.

  3. Zebra Danios: Their small size and active nature can make them a target.

  4. Angelfish: Their long fins and slower speed make them vulnerable.

  5. Betta Fish: Their aggressive nature and smaller size make them unsuitable tank mates.

Breeding Redtail Catfish and Fry Care

Breeding redtail catfish in home aquariums is rare due to their size and specific requirements. However, if you’re up for the challenge, here’s what you need to know:

Breeding Process

  1. Sexing: Male redtails are generally larger and have broader heads than females. However, sexing is challenging, and experts often determine sex by examining internal anatomy.

  2. Spawning: In the wild, redtail catfish spawn during the rainy season. To simulate this, you can attempt large water changes, lowering the temperature slightly to mimic rainwater.

  3. Egg-Laying: If successful, the female will lay thousands of eggs, which the male fertilizes externally.

Fry Care

Assuming successful breeding, looking after redtail catfish fry involves a few critical steps:

  1. Egg Protection: In the wild, redtails guard their eggs. In an aquarium, it may be best to move the eggs to a separate tank for hatching to protect them from other inhabitants.

  2. Feeding: Fry should be fed high-protein food like brine shrimp to support their rapid growth.

  3. Water Quality: Maintain high water quality with regular changes and monitoring. Clean, well-oxygenated water is vital for fry development.

Breeding redtail catfish is an ambitious but rewarding endeavor. Whether you’re considering tank mates or thinking about breeding, your attention to detail will go a long way in ensuring a healthy, vibrant environment for these fascinating fish.

Recognizing Signs of Stress in Redtail Catfish

Just like us, fish can get stressed. Noticing the signs of stress in your redtail catfish can help you to keep them healthy and happy.

Here are some of the telltale signs:

  1. Lethargy: Catfish are usually active, especially at feeding times. If your redtail is not showing interest in food or seems sluggish, it may be stressed.

  2. Loss of Color: Stress can cause redtail catfish to lose their vibrant coloration, appearing duller than usual.

  3. Rapid Breathing: If your catfish is taking rapid breaths, it could be a sign of stress, often linked to poor water conditions.

  4. Hiding or Avoidance Behavior: Redtails are not known to be shy. Constant hiding or avoiding other fish can be a symptom of stress.

Common Health Issues and Treatments for Redtail Catfish

Keeping your redtail catfish healthy means being vigilant about potential illnesses.

Here are some common health issues and how you can treat them:

  1. Ich: This is a parasitic infection that presents as white spots on the fish’s body. It can be treated using over-the-counter medications like malachite green.

  2. Fin Rot: This is a bacterial infection that affects the fins, making them appear frayed. Antibiotics can be used for treatment.

  3. Bacterial Infections: Redtail catfish can also suffer from various bacterial infections which often present as sores or ulcers. Antibiotics are the usual course of treatment.

Additional Tips for a Healthy Aquarium

Creating a healthy environment for your redtail catfish and other aquatic residents isn’t just about meeting their basic needs.

Here are some additional tips:

  1. Avoid Overcrowding: A crowded tank can cause stress and increase the risk of disease.

  2. Feed a Balanced Diet: Ensure you’re providing a varied and nutritious diet to your fish.

  3. Consistent Monitoring: Keep a regular check on your water parameters and fish behavior.

Should You Get a Redtail Catfish for Your Aquarium?

If you have ample space, redtail catfish can make for a unique and interesting addition to your aquarium. They are beautiful and impressive, with a lifespan that allows for a long-term bond.

However, their large size, growth rate, and specific needs mean they’re not suitable for every hobbyist. They’re best suited to those who can provide a large enough tank and are committed to their care over the long term.

If that sounds like you, then a redtail catfish could be the perfect new member of your aquatic family!

The Conservation Status of Redtail Catfish

At present, the redtail catfish is not classified as endangered. The International Union for Conservation of Nature (IUCN) has yet to assess this species, but based on available data, it appears to be reasonably secure in its native habitat.

It’s important to keep in mind that these catfish are vital components of their ecosystems, so responsible pet ownership and trade practices are essential to maintain their natural populations.

Availability & Pricing

When it comes to purchasing a redtail catfish, you’ll find these exotic pets readily available in most well-stocked aquarium stores and online fish retailers.

The pricing typically varies based on size and age. Young, smaller specimens might be priced as low as $20-$30.

However, bear in mind that these creatures grow rapidly, and the initial savings may be offset by future costs associated with larger tanks and increased food consumption.

Frequently Asked Questions About Redtail Catfish

As a redtail catfish owner, you might have a few questions about your aquatic pet.

Let’s explore some common queries:

Q – How big do redtail catfish get?

Ans – Redtail catfish can grow up to 1.8 meters in the wild. In captivity, they typically reach around 1.2 meters.

Q – What do redtail catfish eat?

Ans – These omnivorous fish enjoy a varied diet that includes pellets, live and frozen foods, and occasional fruits.

Q – Can redtail catfish live with other fish?

Ans – Yes, but their tank mates should be chosen with care. Larger, more robust species make better companions.

Wrapping Up: The Marvelous Redtail Catfish

In conclusion, the redtail catfish is a beautiful, intriguing, and vibrant species that could become the star attraction of your aquarium.

Its sheer size and striking appearance are captivating, but they also require careful consideration. Prospective owners need to ensure they can meet the substantial space, diet, and care needs of these impressive fish.

If you’re up for the challenge, the redtail catfish offers a unique and rewarding pet-keeping experience. Their active and inquisitive nature, coupled with their long lifespan, allows for a deep and lasting bond.

Just remember, every redtail catfish deserves a loving and well-prepared home.

Happy fish-keeping!