Upside Down Catfish 101: Care, Size, Tank Mates…

Upside Down Catfish are one of our favorite freshwater species without a doubt. We find ourselves recommending them to other aquarists all the time!

These fish are perfect for fishkeepers of all experience levels. With their unique behavior and low-maintenance care requirements, their popularity isn’t a surprise.

This guide will go over the essential info about Upside Down Catfish care. Size, tank mates, lifespan, and ideal food is all covered!

Species Summary

Upside Down Catfish (Synodontis nigriventris) are certainly one of the quirkiest creatures that you can add to your tank! They exhibit some strange behavior that’s not normally seen in tropical fish. Rather than swimming upright, these freshwater fish spend most of their time swimming upside down!

Usually, that kind of behavior is an indicator that your fish is unhealthy or dying. That’s not the case with the Upside Down Catfish. These fish have adapted for bottoms-up swimming and will spend most of their days scouring the surface of the water or feeding on the underside of driftwood.

Scientifically known as Synodontis Nigriventris, the fish are native to Central Africa. They can usually be found in the Congo River basin throughout Kinsasha, Basonga, and Cameroon. Many of the specimens you see in tanks today are still wild-caught.

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They have become quite popular with aquarists all over the world. Thanks to their eye-catching behavior, hardy nature, and overall peacefulness, they are sure to be a standout in your fish collection.


The average Upside Down Catfish lifespan is about 15 years old! That means this species isn’t for the casual aquarist who isn’t looking for a long-term commitment.

Of course, there are no guarantees with life expectancy. Like any other fish, their health is directly affected by water conditions and diet. Several factors can shorten their life span tremendously.

As a fish-keeper, it’s your job to stay on top of their habitat. Regular maintenance and a carefully curated ecosystem can help these fish live long and happy lives.


These unique fish are very similar in appearance to other freshwater aquarium catfish. They have that same familiar profile complete with three pairs of barbels on their face.

The fish have semi-transparent fins that are equipped with sharp rays. These rays are a line of defense for the fish. They can do a considerable amount of damage, so exercise caution when moving the fish!

Two Upside Down Catfish swimming together

Upside Down Catfish have a large dorsal fin, an adipose fin, and a forked tail. These fins may be flattened while your fish is swimming through the water. However, they will pop them up the moment they feel threatened.

The body of the fish is quite neutral when it comes to coloration. They are covered in splotches of brown. Those splotches take on different shades of brown, creating a nice camouflage effect. The brown is also often accompanied by black spots.

One of the most unique parts of the Upside Down Catfish is its underbelly. With most fish, the belly is significantly lighter than the rest of the body. This is even true with dark fish.

On the Upside Down Catfish, the belly is dark brown to closely match their backs. This shows that the fish has evolved for their strange swimming patterns. The dark belly ensures that they are still camouflaged no matter how they choose to swim.

Average Size

The average size of Upside Down Catfish is between 3 and 4 inches in length. These creatures are on the smaller side compared to other catfish species.

While they might not reach the enormous sizes of some other catfish, this can prove to be quite useful in your aquarium. You can easily pair them with other tropical fish of a similar size. We’ll get into that later.

Author Note: Their size can be affected by the quality of care they receive. If your fish are being kept in suboptimal conditions it’s far less likely that they’ll reach their maximum length.

Upside Down Catfish Care

For the most part, Upside Down Catfish care is a task that’s considered to be fairly easy. They are surprisingly resilient, aren’t too fussy, and not high-maintenance like some other species out there.

Of course, that doesn’t mean that you can pop them into any old tank. They do have some care requirements that you need to abide by. Sticking to some established guidelines will ensure that the catfish can truly thrive in your aquarium.

Tank Size

The ideal tank size for Upside Down Catfish should be at least 30 gallons. While some aquarists have not had any problem keeping these fish healthy in tanks as small as 10 gallons, we advise against it.

That small tank size could pose an issue as your fish gets older. At the end of the day, Upside Down Catfish need as much room to roam as possible.

With a 30-gallon tank, you can keep a small group together and even introduce a few tank mates. The aquarium will be big enough to give every fish swimming room without feeling cramped.

Water Parameters

While the Upside Down Catfish helms from Central Africa, their ecosystems aren’t too different from other tropical fish that come from Asia or South America. They like warmer waters that are filled with vegetation.

The biggest things you’ll need to pay attention to are pH and hardness. Unlike other fish, the Upside Down Catfish prefers moderately soft water. It should also be relatively neutral. Some slight acidity is tolerable, but your pH reading should stay as close to neutral as possible.

Here are some important water parameters to pay attention to:

  • Water temperature: 72°F to 82°F (between 75 and 79 degrees is ideal)
  • pH levels: 6.0 to 7.5
  • Water hardness: 4 to 15 dGH

Upside Down Catfish are very sensitive to ammonia and nitrate levels. If you have a large community tank, it won’t take long for nitrate levels to go beyond acceptable levels if you’re not paying attention.

In addition to a strong canister filter (our favorite is the Fluval FX4), you’ll need to perform regular water changes. We recommend swapping out about a quarter of the water every couple of weeks to keep things in order.

Setting Up Their Habitat

Creating the right environment with tank decorations is just as important as keeping the water quality in check. The goal is to recreate their natural habitat and introduce some accessories that work with their lifestyle.

As we mentioned earlier, these fish swim upside down regularly. The main reason they do this is to feed on the underside of rocks, caves, and plant leaves. Needless to say, having plenty of those things around is essential.

Large pieces of driftwood are a favorite for these fish. The same goes for sizable caves.

Try to introduce some accessories that are large enough for a group of fish to share. They are social creatures that often stick together, so having some areas they can share is always good.

As for plants, stick to broad-leaf varieties. Anubias, Echinodorus, and other floating plants are a good start. These plants have leaves that are big enough for the fish to swim under and feed on.

Another important consideration is water flow. Upside Down Catfish prefer a strong flow. They’re pretty resilient and will use their mouths to latch onto whatever they are feeding on. You can create a stronger flow with a water pump or by simply using the outlet tube of your filter.

Oxygenation is crucial, too. The fish do best in highly oxygenated water, so consider installing an air bladder or bubbler somewhere in the tank.

Common Possible Diseases

Contrary to popular belief, there’s nothing wrong with the Upside Down Catfish. Despite their quirky behavior, these fish are known to stay quite healthy!

Ichthyologists have examined their internal organs and found that there are no differences with the swim bladder or balance mechanism. They have just adapted to swimming upside down!

These fish are susceptible to other tropical fish diseases like Ich or bacterial infections. However, they tend to stay on the healthier side of things.

The most common issue that owners have to deal with is infected barbels. This happens when the nitrate levels get too high. The infection could affect their ability to get around. Plus, it could lead to other issues if not addressed.

Author Note: The best way to avoid infected barbels and other diseases is to simply stay on top of water conditions. By keeping your tank in good shape, there’s less chance of stress and disease.

Food & Diet

Upside Down Catfish are omnivores by nature. In the wild, they will typically skim the surface of the water for insect larvae. Then, they’ll make their way back down and eat whatever they can find under driftwood and plant leaves.

In captivity, most fish are willing to accept whatever you give them. They do best on balanced diets that are rich in protein.

You can provide commercial dry foods for their main meals. This could include sinking pellets, algae wafers, and even standard flakes. However, we also recommend providing some live food.

Brine shrimp, larvae, bloodworms, and more are all good supplements to dry food. They can keep your fish in good shape and help them reach their full potential.

Behavior & Temperament

Like many other catfish species, the Upside Down Catfish is largely nocturnal. They will spend most of their time hiding during the day. That’s why it’s so important to add rocks, caves, and driftwood!

Once the sun sets, the fish will become more active. They don’t limit themselves to just one part of the water column, so be prepared to see them swimming everywhere!

Synodontis nigriventris moving in the middle of a freshwater aquarium

These fish are very peaceful and get along just fine with other non-aggressive fish. That said, they do best in groups of three to four fish of the same species.

When kept in groups, they get more confident and social. You may even see them start to come out during the day instead of spending their time hiding!

You’ll also see them swimming in a couple of different ways, but they obviously spend most of their time upside down.

However, they are capable of swimming upright. Whatever they do, they’ll often stay in the same position for hours on end.

Upside Down Catfish Tank Mates

Because these catfish are on the smaller side, you need to avoid any fish that could potentially see them as prey. Avoid all aggressive fish and stick to similarly-sized peaceful ones.

It’s not just the health of your Upside Down Catfish you have to worry about with large aggressive fish.

Remember those sharp rays we mentioned earlier? Well, your catfish will use them if they are ever attacked by an aggressive fish.

Those rays are known to get stuck in the throats of larger fish that try to eat the catfish. This can lead to serious injury or death! It’s best to just keep things peaceful.

In addition to other Upside Down Catfish, here are some good tank mates to consider:

Author Note: You can also try pairing these fish with some of the popular types of freshwater aquarium snails as well. 


Breeding Upside Down Catfish is very difficult. Most of the fish you see in stores are either wild-caught or bred using reproductive hormones.

Some aquarists have been able to successfully breed these fish, but it’s hit or miss.

They are egg-laying fish that will usually spawn when spring rains occur. The best way to increase your chances of successful spawning is to recreate those conditions as best as possible.

Keep a group of catfish together. They usually naturally pair off when it comes time to breed. Typically, females are duller and a bit rounder than the male specimens.

Introduce some large cave systems into the habitat. You can use PVC pipes or overturned flower pots. Then, raise the temperatures to around 80 degrees.

Next, provide your fish with lots of live foods to trigger the breeding process.

You can also try sprinkling cold water into the tank with a watering can. This is said to mimic the cooler rains of spring.

If done successfully, the female will lay upwards of 450 eggs! The male and female will protect the eggs, so there’s no need to worry about them eating the eggs. Though, you may want to remove any other fish in the tank for good measure.

In about four days, the eggs will hatch. The tiny fry will continue to feed off their egg sac for another four days until they’re ready to accept baby brine shrimp.

Continue raising these baby fish and provide plenty of protein-rich foods. By about two months old, they should start swimming upside down!            

Want To Mix It Up A Bit?

We hope this guide has not only educated you on Upside Down Catfish care, but also convinced you to give this species a shot!

They’re low-maintenance, durable, and a blast to observe. We know plenty of aquarists who swear they’ll always keep a tank of these fish no matter what.

If you have a question about something we didn’t cover in this guide we’re more than happy to help you find the answer. We want to do whatever we can to help other fishkeepers experience the joy of owning this species.

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