Redtail Catfish Care: Diet, Size, Tank Mates, and Diseases

The redtail catfish, otherwise known as phractocephalus hemioliopterus, is a type of catfish we see that is common in aquariums. It is native to South America and is interestingly the only surviving member of its genus – catfish phractocephalus. It makes most of South America its home and can be found in South American river basins in Ecuador, Guyana, Venezuela, Colombia, and more.

Redtail Catfish

They are among the large aquarium fish we can see in the trade and are one of the fastest growing as well. Catfish are not known for their beauty, hence the term “catfished”, however, the phractocephalus hemioliopterus is actually considered one of the more attractive members of this family. Although the redtail catfish is often seen in the aquarium trade, it is very unsuited to tank life due to its sheer size.

Redtail Catfish: A Quick Overview

Redtail catfish, also known as Phractocephalus Hemioliopterus, is a large, predatory fish native to South America. It is popular in the aquarium trade due to its striking appearance and hardy nature.

Redtail catfish can grow to over 3 feet in length and require a spacious tank with strong filtration. They are generally peaceful, but may eat smaller tank mates.

Redtail Catfish Overview

Let’s take a look at how to care for this large fish and familiarize ourselves with more details about this species.

Information ChartRedtail Catfish
Care Level: Medium to difficult
Temperament: Aggressive
Color: Dark brown, grey with a thick yellow/white band
Lifespan: 15 years
Size: 3-4 feet
Family Phractocephalus
Diet: Omnivorous
Minimum Tank Size: 31500-2000 gallons
Temperature: 68-80 ºF (20-26 ºC)
Water Conditions: pH 6-7
Tank Mate Compatibility Larger non-aggressive fish



While they can be colorful, most of them feature shades of dark brown and/or grey with spots and a thick yellow/white band that runs along the length of their torso. Aside from the tail fins, the dorsal and caudal fins also feature hues of red and orange. Similar to other catfish species, the redtail catfish also features a flat underside.

As far as sexing goes, there don’t seem to be distinguishing marks to help breeders and aquarists determine if the catfish is male or female.

Lifespan of Redtail Catfish

Redtail catfish live relatively long lives. In captivity, data shows that they can live to about 15 years. It is assumed that they exceed this number in the wild due to more suitable environments. They are quite a demanding species of fish, and what they require may be difficult for aquarists to provide in-home tanks. This is a factor that can shave years off its life.

Redtail Catfish Life Span

To create the perfect situation for these creatures to thrive, you need to pay attention to the different subsections we have listed below. We can say for now that to give them enough space, the right food and ideal tank conditions are crucial elements for the phractocephalus hemiolipterus to thrive.

Remember that this particular catfish is native to South America, more specifically, in the river basins. This means that they are considered freshwater fish that need an aquarium with water and temperature similar to that in South America.

Redtail Catfish Size

How big can a red tail catfish get? As we previously mentioned, redtail catfish are quite large freshwater fish. Large enough to outgrow their initial tanks. The redtail catfish is said to be one of the more attractive catfish species with beautiful colors and, of course, a red tail. Similar to other catfish species, they also feature two barbels on their mouths.

How fast do red tail catfish grow? They grow quite quickly and to a pretty large size. You’re looking at at least an inch a week and they will be at least two feet in length in about a year. Keeping them in tanks limits their freedom of movement significantly compared to the wild, which is why they won’t grow as large in size as they would in the wild. At best, they will be about 3-4 feet long, when in the wild they may reach up to a whopping 5 feet in total!

Redtail Catfish Size

For a fish in captivity, 3 feet is gigantic. Not only in terms of the fish, but also in the tank size. It may be hard to search for a tank large enough to house the redtail catfish in just any aquarium store. A baby phractocephalus hemioliopterus is only about 5 cm, which is why a lot of aquarists are not aware of how large they may potentially be.

Aquarists may be under the misconception that keeping the redtail catfish in captivity at a young age could limit their growth. Although this is true, they will still most definitely reach at least 3 feet long. Regardless of how much “stunting” captivity has on your redtail catfish, the tank size will still need to be astronomical.

The largest recorded retail catfish in the world is measured at 4.62 feet and weighing in at an astounding 56 kg (123 pounds 7 ounces)! If you ever see pictures of these amazing catfish, you will be amazed by how large they can be compared to the average human male.

Natural Habitat and Origin

The redtail catfish is of the primelodidae family (whiskered catfish) under the phractocephalus family in the hemioliopterus genus. The experts say the RedTail Catfish is normally found in the Essequibo River, Orinoco, and Amazon River basins of Brazil, Venezuela, Guyana, Colombia, Ecuador, and Bolivia. Even though they live in the rivers, they can also be found in different habitats.

But they have now been introduced to other parts of the world, including Thailand. They can also now be seen in Florida as well.

Some experts say the Redtail Catfish are the only living member of the Pharactocephalus species. They are also called RTC, the banana catfish, the antenna fish, and the flat-nosed catfish.

Redtail Catfish Care & Tank Set-Up

Redtail Catfish Tank Size and Specifications 

Minimum Tank Size

As we mentioned, this catfish with a red tail is not easy to care for. If you are determined to keep one in your home, here are a few things that are absolute musts. Just knowing the tank size may put you off a bit. In order to have enough room for ONE adult redtail catfish, the tank size you are looking at is about 1500-2000 gallons. No, we did not include an extra zero.

Since they get to about 3-4 feet, this is the adequate size to keep them happy and have enough room to roam. The tank size is definitely something that you cannot compromise on. With this, many people forget about ever owning a redtail catfish because a tank this big just isn’t doable for regular people.

Redtail fish Tank Size

The juvenile RedTail Catfish can grow much faster than other fish, around 1 inch in a week for the first two years. That’s why you may need to use a larger fish tank within a few months. But you should remember that upgrading your tana can be a little stressful for your fish. So, to help them ease the stress, you can transfer the water from the old tank to the new tank. This way, you can make sure that the parameters remain the same, and your fish will be able to adjust to the new environment. 

Besides, you can also have tank materials transferred from your old water filter system to the new one during cycling the tank. Before transferring your fish, you should finish the nitrification cycle. 

If you want to add décor items to the aquarium, you should ensure they don’t have any swallowable parts. Use décors as large as your catfish to prevent them from trying to eat the items. 

Because of their nature, they may like to destroy the décor. So, it will be better for you to use big rocks and large branches in the tank. An aquarium with nothing on its bottom will work great. However, if you think that looks dull, you can use sand to cover the bottom section. 

On the other hand, as Redtail Catfish are not social-type, the tank’s lighting condition should be subdued. If you can’t do that, you should add more dens and caves to the tank to create hiding spots.

Water Parameters for Redtail Catfish


As mentioned, redtail catfish are very resilient and can withstand and adapt to many conditions, but getting the water conditions just right will only further benefit the phractocephalus hemioliopterus. The ideal water temperature should be between 68 to 80 degrees Fahrenheit (20-26 degrees Celsius) with pH levels sitting between 6 and 7.

Water Conditions

The water quality is among the toughest to maintain for a redtail catfish. This is due to the enormous size of the tank and the fact that they eat a lot. The more fish eats, the more waste there could possibly be. Suffice it to say, most of your time may be spent on monitoring the water conditions.

In terms of decoration and populating the tank with a substrate, don’t put too much! As we mentioned, the phractocephalus hemioliopterus eat just about anything. We mean anything ranging from gravel to pieces of floating debris and even the plant substrate. So you are looking at a very large and sparse tank. This is great in a way because a tank with less in it can mean less cleanup and maintenance.

It may not look as nice as a lush green tank, but it’s what they need. Speaking of what they need, since they are bottom dwellers, place the tank in low light areas as well.

Water Flow Rate

The water conditions need to be regularly maintained. Since they are freshwater fish, you may need to pay a closer eye on the soiling of the water due to waste. River basins generally do not have a high flow rate so still waters are fine. For such a large tank, traditional filters may have a difficult time dealing with the water, so opt for a sump filter instead. Unfortunately, a good sump filter can really rack up the bill.

Since they are considered tropical (due to them originating from The South American Amazon Orinoco river basins), you may need to invest in a separate water heater if you are unable to maintain the constant warmer temperature. Since the aquarium tends to be much larger in size compared to regular tanks, it may cause your heater to work overtime and rack up the electricity bill.

They can get used to different environments and water flow rates, but what’s more important to keep an eye on would be the water temperature, tank size, and what you keep in the tank with them.

Feeding Redtail Catfish

What do red tail catfish eat? Fish this size need to eat a lot of food, right? You’re right! Redtail catfish are big eaters and will eat just about anything. Just because that is the case, it doesn’t mean that that is what you should do. Simulating their natural diet in the tank will help prolong their lifespan. In nature, the phractocephalus hemioliopterus eats worms, other fish of a smaller size, insects, and vegetation along the bottom of the river basins.

Best Diet for Redtail Catfish

In captivity, you can also opt to feed them smaller fish and worms but substitute the others with shrimp, and some pellet food. Flakes are advised against since flakes don’t generally sink. If you opt for pellet food, you need to choose the sinking variety as that is where your redtail catfish spends most of its time.

They are omnivorous fish but prefer meats. This is why having a supply of frozen food can help satisfy their hunger. They don’t actually need to be fed much. The younger phractocephalus hemioliopterus need food every other day but full-grown redtail catfish can do well with one large meal a week.

How often should you feed Redtail Catfish?

You know when it’s time to feed them when your fish become active again. This is because the phractocephalus hemioliopterus need time to digest their food and become lethargic after feeding (sort of like you after turkey dinners). Overfeeding is an issue commonly seen among fish. It’s hard to gauge when some species need food but consistency is key remember that they can go a long while without food.

Don’t feed your Redtail Catfish the meat from mammals. Beef and chicken contain lipids, and your fish won’t metabolize them. Such types of meat can also lead to organ degeneration and excess fat deposits.

Can you eat a redtail catfish? This is a funny question that we are often asked. Because of their size, they are unfortunately considered a game by some. However, the natives of South America don’t generally eat the meat because the fish is often dark in color.

Redtail Catfish Care Level

In a word, caring for the redtail catfish is difficult, which is why they are not recommended for first-time aquarists. They need a large tank due to their size and aren’t the most friendly fish in the sea. On the plus side, they are freshwater fish, which means you don’t need to pay too close attention to the salt levels in the tank.

They are resilient and can adapt to a broad range of habitats, which is why they are considered an invasive species by some. An invasive species means a species that has the power to force out other species that are native to a specific area. This resiliency is also what makes them not as sensitive to certain tank conditions.

Even though they are tough, the right environment is still required to keep them happy and healthy. In captivity, the redtail catfish won’t live as long as it could potentially in its natural habitat. Their size is again something to consider. There are many cases of redtail catfish outgrowing the aquarium at home and because the aquarist cannot accommodate it anymore, they are donated to aquariums.

If you do not have an aquarium large enough to house the redtail catfish until maturity, we would advise you to search for another species that is of a more reasonable size.

Redtail Catfish Behavior and Temperament

Fish are either peaceful or aggressive, but these catfish although many agree are aggressive, can fall somewhere in between. Redtail catfish are predatory freshwater fish. If these natural instincts kick in, then some may argue that they are quite aggressive. Factors that influence their temperament and behavior include the environment.

Are Redtail Catfish lone or societal in nature?

When they are young, they can be a little shy or nonsocial. So, to help them in overcoming their shyness, you should offer sufficient space to hang out, such as dens and caves. Besides, it will be much better for you to keep your aquarium out in the open, where you spend a lot of time. This will help your fish to get accustomed to witching and interact with you. 

Redtail Catfish generally love to swim at the bottom of the tank. When they are adults, you will find them remaining motionless for hours. Due to their completely evolved receptors and stealth capability, they are the predators that can wait for hours for their prey. 

They have a bad habit of putting anything in their mouths. They can even swallow the items. This can be dangerous for your fish and can also lead them to choke. They can even die due to this. So, while adding things to the aquarium, don’t use objects that will easily fit into your fish’s mouth.

Your tank setup will largely dictate how your fish acts. However, the most common display of behavior by the redtail catfish is roaming the bottom of the tank. They slowly pace around the bottom of the tank as most other catfish do. Before the catfish matures, some aquarists say that they can be quite timid. Giving them lots of places to hide can help.

They love to live with their kind or other catfish families. But that doesn’t mean they will not live with others. Redtail catfish can be an ideal community fish if you use fish of the same size. In large public aquariums, they can easily live in large groups. Redtail Catfish are not at all venomous. However, they can be very predatory towards the things they find smaller than them, such as crabs, shrimps, snails, and more.

Redtail Catfish Tank Mates

Imagine a single catfish floating around with no friends in a sparse tank. The situation seems pretty bleak, but it’s okay, you can add some tank mates (on the condition that they are suitable of course). It’s tough to find the right aquarium buddies for these fish because they are large, somewhat aggressive, and will eat almost anything. The phractocephalus hemioliopterus eat smaller fish, so definitely make sure the tank mates you select are not much smaller.

Due to their large size and the fact that Redtail Catfish consume smaller fish, choosing a good tank mate can be a challenging task for you. One of the most common issues is that most types of freshwater aquarium fish are very smaller than the Redtail Catfish. When getting tank mates for your Redtail Catfish, you should consider the size first.

Ideal Redtail Catfish Tank Mates

When they are small, you can keep them with fish of the same size. For example, AngelfishGouramisSilver Dollars, and Tiger Barbs are good tankmates until your catfish outgrows them. Even though they are voracious, they are not that much aggressive. They can live comfortably with the below and with other bottom dwellers. 

Some of the good tank mates for your Redtail catfish can be Stingrays, Pacu, Arowanas, Adult Plecostomus, Umbees, Peacock Bass, Oscars, and other large fish.

Breeding Redtail Catfish

Breeding with these large fish is extremely difficult. In a regular aquarium, even one of 2000 gallons may not be large enough for 2 of these might catfish and this makes it tough to create the circumstances in which they mate. Even in large ponds, it can be difficult for successful breeding.


Look for fish that are the same size or larger with a focus on non-aggressive temperament. Introduce your catfish to his or her new friend early on so they have time to get acquainted. To minimize trouble, those that do go ahead in keeping redtail catfish usually only keep one. Adding more creatures to the tank only adds more issues such as tank size and having to add some sort of substrate and plants to accommodate the other species can compromise your catfish.

Beautiful stingrays can be optimal tank mates. Some beautiful smaller sharks such as the iridescent shark can also hold their own against the phractocephalus hemioliopterus. Ideally, though, we suggest keeping your catfish solo in a tank.

Redtail Catfish Common Diseases and their Treatment

Though hardy, they are not immune to some diseases. Just like most aquarium fishes, stress, poor-quality water, and an unhealthy diet are some of the risk factors that can severely affect your Redtail Catfish’s health. Some of the most common health issues that your Redtail catfish may develop are: 

Fin Rot

This is one type of bacterial infection that can affect most freshwater fishes. When it happens, the Redtail catfish’s edge will begin to move away due to the adverse bacterial activity. If not treated soon, this can affect other parts of your Redtail Catfish. You may see discoloration, and your fish will gradually lose appetite and may develop lethargy. In some cases, inflamed patches can be seen on your fish body. To treat this condition, you can use different antibacterial medications like amoxicillin or fish doxy. If you are using this for the first time, you can take the help of an expert. 


It is quite common for Ich to affect the fish that are under stress. Different factors commonly cause this, for example, pH variations, increase in temperature, and more. Some common symptoms to consider here are white spots on the body, rapid breathing, and glancing. You can try changing water or can check the pH level.

Ammonia poisoning

Redtail Catfish can tolerate ammonia. So, if the ammonia content goes up in the water, they will develop health issues. As per the experts, ammonia poisoning can disturb or damage the gills, and catfish will develop respiratory complications. Besides, a higher level of ammonia in water can lead to burning on the fish. 

It has been seen that Redtail Catfish exposed to ammonia poisoning can develop red streaks, witness lethargy, and can have torn fins. Besides, your fish may become reclusive. In some cases, your Redtail Catfish can develop aggressive tendencies. But don’t worry at all as this condition is easily preventable. For this, you should constantly check the ammonia level in the aquarium. The experts suggest it should be around 0mg/1. 

In the rising level of ammonia, you should try to lower the pH level and keep changing the water constantly. You should also discontinue feeding for around one to two days. Your catfish should start acting normally after a few days. 

Red Pest Disease

This is generally caused by one type of bacterium. It commonly targets fish’s circulatory system and other organs and tissues. This health issue can lead to internal bleeding. Speaking about the symptoms, some common symptoms are red streaks, bloated stomach, fin or tail rot, and more. Your fish will begin to swim abnormally and come to the surface quite frequently for oxygen. This condition is also treatable. 

You can use a combination of different medications, like tetracycline, acriflavine, and monacolin. 

Apart from these common Redtail Catfish diseases, they are also prone to fungus, constipation, hemorrhagic septicemia, and more due to their eating habit. So, you should carefully observe your fish for any behavioral changes that can suggest a diseased condition. And you should start treating your fish as soon as possible.  

Facts About Redtail Catfish

  • They come with a broad head with whiskers and white underneath, extending to the caudal fin from the mouth. In some rare cases, the tail may find pelvic, anal fins, and the dorsal is also red. 
  • They can grow up to 5 feet and weigh around 80 to 85 kg. 
    During the daytime, they remain motionless, and they hunt and eat during the night. They are bottom-dwellers. 
  • They can eat small fish, fallen fruits, and crustaceans. 
  • They have a well-developed tactile sense and a good sense of sight.
  • Redtail Catfish generally communicate by producing a clicking sound.
  • These fish breed through external fertilization after laying eggs. 
  • Redtail Catfish species have not been evaluated by IUCN. 

Are Redtail Catfish right for you? 

They will start cute and small, but with time, they will grow bigger and much faster than other fish. When taken care of and fed properly, they can easily outgrow the aquarists’ fish tank. When the fish attains such a large size, you may need to donate them to a public aquarium or zoo. But the problem is that sometimes they don’t accept privately kept large fish. So, consider this thing while buying a Redtail Catfish.

By offering proper care and a living environment, you can increase the lifespan of your catfish by up to 20 years and more. That’s why Professional and experienced aquarists generally keep Redtail Catfish. So, if you are not quite confident about this, you should get a smaller fish. 

The question here is, can you offer them the most comfortable life possible? This will include a large fish tank with sufficient swimming space or a pond. Besides, you will have to feed them properly and change the indoor pond or aquarium water properly. 

FAQs (Frequently Asked Questions)

Are Redtail Catfish Hardy? 

Well, these are extremely hardy species. Due to their characteristics, they can easily adapt to almost all types of environments and can easily survive in any water condition. However, they also have some preferred elements. You will have to offer them the best life and environment possible. You need to ensure that the water pH and temperature level of the water are at the required level. Besides, you will have to offer them enrichment. 

What Is The Right Temperature For Your Redtail Catfish? 

Even though they are adaptable and hardy fish, they still have some requirements that you need to follow. By meeting those conditions, you can increase their lifespan. As per the experts, the best temperature for your Redtail Catfish is around 20 to 26-degree C. If you have a small Redtail Catfish, then you can use a normal aquarium heater. You will have to use advanced hearing solutions that can cost you more for the pond. 

Can They Survive In Cold Water? 

Considering their natural habitats and origins, it can be said that they may not be able to survive in cold water. Speaking about their natural habitats, they are large lakes, streams, and rivers, and they never get cold. So, these fish are not ready for cold water. So, if you have an outdoor pond, you should keep it warm during the winters. 

How Can Long Redtail Catfish Survive Without Food? 

A well-grown and healthy Redtail Catfish can live around three days to one week without consuming any food. Some fish species can live more than two weeks. Whether in an aquarium or nature, your Redtail Catfish has sufficient fat and body mass reserves to skip their meals. 

Who Are Ideal Tank Mates of Redtail Catfish? 

They can attack and eat small species, Datnoids, Stingrays, and Gars can be good tankmates of your Redtail Catfish. For best results, you should keep them together from a young age.

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The phractocephalus hemioliopterus is quite the trophy fish to keep. It will surely attract a lot of attention to have such a majestic yet menacing predator swimming in a home aquarium. Since they are so large, an aquarist needs to be prepared for all it will take to raise these creatures in captivity. This includes the large aquarium and regular water maintenance. Since they are predatory in nature, we recommend they be kept alone.

You should remember to keep them with you and have a correct setup. Besides, keeping them for around twenty years can attract an expensive food bill as they have a voracious appetite. You will need years of experience, sufficient resources, and space. However, if you have sufficient fun and the means, then they can be a truly amazing giant to keep. It may be a little challenging, but it is not impossible to keep this fish.

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