Upside Down Catfish: A Quirky and Distinctive Aquarium Fish

Alison Page

Alison Page


upside down catfish

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The Upside Down catfish gets its name from its weird upside-down swimming style that enables the creature to feed more easily on the water’s surface. This quirky little fish is incredibly popular in the hobby and has been around for centuries, even appearing in ancient Egyptian artworks!

But are these strange little fish suitable for a beginner’s tank? What do Upside Down catfish eat? And can these bottom-dwellers live in groups?

In this guide, we tell you everything you need to know about the Upside Down catfish, its origins, care, and breeding!

Upside Down Catfish – At a Glance

Upside Down Catfish Info
Scientific Name:Synodontis nigriventris
Common Name (species)Blotched Upside Down catfish, Upside Down catfish
OriginCentral Congo River Basin
Care LevelEasy
Size4 inches
Lifespan5 years
TemperamentPeaceful, social, schooling species
Minimum Tank Size10 gallons
Temperature Range72° to 79° F (22° to 26 C°)
Water Hardness4 to 15 dGH
pH Range6.0 to 7.5
Filtration/Flow RatePrefers a strong flow and well-oxygenated water
Water typeFreshwater
BreedingEgg-layer, cave spawner
OK, for Planted Tanks?Yes, does best in a heavily planted tank

Origins and Natural Habitat

The Upside Down catfish is found in Central Africa, specifically in the Central Congo River Basin, ranging from Basonga to Kinshasa, and it’s also common in Cameroon, where you’ll find these fascinating little fish living around densely vegetated areas close to riverbanks.


Like other members of this family of fish, the Upside Down catfish has large eyes, a forked tail, a large adipose fin, and three pairs of barbels. The fish’s body is light brown and covered in darker brown blotches of different sizes, which gives the fish its other common name, Blotched Upside Down catfish.

These fascinating fish have evolved this color adaptation that enables them to spend much of their lives swimming upside down. Unlike most fish species that swim right side up, the underside of the fish’s body is darker in color, which serves to camouflage the Upside Down catfish when it is feeding upside-down at the water’s surface.

Like many other catfish species, such as Corydoras catfish, the Upside Down catfish has sharp fin spines that you must be wary of when moving the fish using a net, as it is very easy for them to become entangled and injured.

Differentiating the Sexes

If you want to try a breeding project, you will need to know how to tell males from females. Although it can be tricky to tell the difference between the two sexes when the fish are juveniles, adult female Upside Down catfish are usually larger, have plumper, rounder bodies, and are lighter colored than males, especially when in spawning condition.


The Upside Down catfish is considered to be a dwarf species, only reaching an adult size of around 3 to 4 inches long.


Like many dwarf catfish species, the Upside Down catfish can live to around five years, although I have kept some that lasted for longer than that.


Upside Down catfish are primarily nocturnal, although they will come out during the daytime when kept in groups in a tank with subdued lighting and plenty of cover.

These relatively active fish spend much of their time scavenging around the tank for morsels of food. Although Upside Down catfish can swim faster when upside down, they also swim right-side-up for quite long periods, especially when grazing on the bottom of the tank looking for food.

Interestingly, when scientists examined the inner structures of this catfish, they found that the swim bladder was normal, and there was nothing strange about the fish’s balancing organ in the ear, which looked just like those of other catfish species.

How to Care For Upside Down Catfish

If you want to keep a few of these beautiful, unusual dwarf catfish, you’ll need to know how to care for them, and we cover that in this section of our comprehensive guide.

Upside Down catfish are ideally suited to life in a well-maintained aquarium

Minimum Tank Size

Upside Down catfish Should be kept in a tank of at least 10 gallons with a tightly fitting lid or cover slide to prevent dust and debris from getting into the water.

Water Parameters

The aquarium water temperature is not critical for these tropical freshwater fish, although 72° to 79° F (22° to 26 C°) is ideal.

The water should be moderately soft, around 4 to 15 dGH, and with a slightly acidic to neutral pH in the range of 6.0 to 7.5.

Upside Down catfish are highly sensitive to nitrates, and pristine water conditions are essential to keep these fish healthy and thriving. For that reason, you must be prepared to carry out frequent partial water changes and check the water chemistry in your tank regularly using an aquarium water testing kit.


These fish prefer subdued lighting, and regular LED aquarium lights are fine, provided you use plenty of fresh plants to create dappled shade for the fish. Alternatively, you might want to use blue-moon illumination, which will allow you to observe the interesting behaviors of these primarily nocturnal fish.


Upside Down catfish also need well-oxygenated water and a relatively strong current, which you can easily achieve by using a spray bar water return fixture in combination with a canister filter or powerheads. To prevent the fish from being buffeted by a heavy current, be sure to provide plenty of hiding places where they can shelter in turbulent areas of the tank.

Tank Decoration

Upside Down catfish are happiest when kept in a well-planted tank filled with broad-leafed plants since the fish like to browse and graze on the undersides of the leaves. In the wild environment, it’s normal for this species to gather and congregate underneath rocks, driftwood, and leaves, so be sure to offer plenty of opportunities for the fish to show that natural behavior in your tank.

I think the best way to display these catfish is in a natural-looking environment with a soft, sandy substrate that won’t damage the fish’s sensitive barbels and plenty of pieces of driftwood, rockwork, and smooth river stones. Remember that these fish are mostly active at night, so give them a few caves where they can shelter during the daytime.


Upside Down catfish are omnivores that enjoy a diet consisting of mostly meaty proteins, such as water-bound insects that the fish catches at the water’s surface, and they also scavenge underneath submerged branches and leaves for insects, micro-organisms, and worms. When you consider the fish’s natural diet, you can see why it has evolved to swim upside down, as that makes access to these food sources relatively easy.

In addition to meaty foods, the fish will also graze on whatever algae are available in their environment to supplement their diet.

In captivity, you can feed your Upside Down catfish a variety of foods, including commercially prepared sinking catfish pellets, frozen foods such as bloodworms and blackworms, and freeze-dried tubifex and bloodworms.

To keep your fish in optimum health, you should provide a diet that includes live insect larvae, ideally mosquito larvae, when possible. You can also feed your fish vegetable matter in the form of cucumber and shelled peas.


upside down catfish

Upside Down catfish are peaceful creatures that can make an unusual, interesting addition to a community tank of non-aggressive fish of a similar size.

Tank Mates

The Upside Down catfish makes a good community fish, being peaceful and happy to live with many other fish species that share the same water conditions and dietary requirements. Even though these fish are pretty friendly, they are omnivores and will eat very small fish and fish fry if they can catch them.

These catfish do best when kept in small groups of at least three or four individuals, which gives them the confidence of safety in numbers and encourages the fish to stay out in the open where you can enjoy them rather than hiding away among your plants.

Some suitable tank mates for Upside Down catfish include dwarf cichlids, African tetras, and small Elephantfish.

Tank Mates To Avoid

As mentioned above, although these are good community fish, they will eat very small fish and fry.

In addition, you should not keep Upside Down catfish with larger fish that will attempt to eat them, as the catfish will erect its spines and could cause the predator to choke. For that reason, I recommend that you never house this catfish with aggressive species.

Health and Disease

Upside Down catfish are relatively healthy tropical fish that will do very well when kept in optimal conditions in a clean, well-maintained aquarium.

These scaleless catfish occasionally suffer from common tropical fish diseases, including White Spot disease (Ich) and bacterial infections. However, the most common problem for most catfish species is barbel damage and subsequent infections, although you can prevent that by providing a soft substrate that won’t damage the fish’s barbels when they’re scavenging around the tank bottom.

As these fish are highly sensitive to water chemistry, I recommend introducing them to a well-established tank with a stable environment rather than placing them in a brand-new setup.


When introducing any new fish to your collection, I recommend placing the newbies in a separate quarantine tank for at least two weeks until you are sure they are healthy and free from disease.

Be sure to acclimate your new Upside Down catfish when adding them to your main display tank to prevent shock and stress that could lead to disease outbreaks.

Breeding and Reproduction

Because Upside Down catfish are naturally cave spawners, persuading them to breed in the aquarium is extremely challenging. However, you might be lucky if you provide an upturned terracotta plant pot or some pieces of PVC piping as potential spawning locations.

To bring your fish into spawning condition, you need to feed them live foods for a couple of weeks before encouraging them to breed. In addition, you can replicate natural breeding conditions by softening the aquarium water and using a watering can rose to add cooler water to the tank, mimicking the spring rains that trigger breeding.

Upside Down catfish typically lay their eggs on the roof of a cave, depositing up to 450 eggs in one spawning. Unlike some other species of dwarf catfish, such as the Corydoras catfish, Upside Down catfish are pretty good parents and can be left in the tank after spawning, as they will tend to their eggs and fry.

The eggs typically hatch in around two to three days, and the fry will initially feed off the yolk sac that remains attached to them for another four days. Once the fry has exhausted the yolk sac, you can start feeding the babies on freshly hatched brine shrimp.

Initially, the fry swims in the upright position before taking up the more familiar inverted position, and once they are two months old, they will start swimming in the species’ characteristic upside-down way.

Availability and Price

Upside Down catfish are commonly found in good fish stores and can also be bought from online breeders.

The fish usually cost around $10, although deals can often be had if you want to buy a group of five fish or more, which we recommend since they do better when kept in small schools.

Final Thoughts

The Upside Down catfish is an unusual tropical freshwater species that can do well in a community tank with other peaceful species that are not small enough to be viewed as a food source.

This strange nocturnal catfish is easy to care for and can make a good addition to a beginner tank. As their name suggests, Upside Down catfish have a peculiar adaptation that enables them to swim upside down, feeding at the water’s surface or grazing on the underside of broad leaves and driftwood.

These fish are egg layers, although they are not easy to breed in captivity because they are cave spawners. However, the species is readily available from good pet stores and online breeders since they are not endangered in the wild environment.

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