Upside Down Catfish Care: Size, Diet, Tank Mates & More!

Upside Down Catffish
Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: May 13, 2024
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Perhaps you’re unfamiliar with the upside down catfish – we were too! This isn’t just a regular fish, it’s an exceptional underwater resident that needs little maintenance. Its distinguishing swimming habits make it a perfect pick for both those new to fishkeeping and those that appreciate uncommon species. Dive into this thorough care guide to discover more about this remarkable water inhabitant.

Article Summary

  • The Upside Down Catfish has a unique swimming style, where it often swims upside down.
  • To keep Upside Down Catfish happy and healthy, you should provide them with at least a 20-gallon tank with appropriate substrate, plants, and hiding places.
  • Regular tank maintenance is crucial to prevent diseases like swim bladder disease, bacterial infections, and constipation.

Species Overview

Common namesBlotched upside down catfish, mochokid catfish, false upside down catfish
Scientific nameSynodontis nigriventris
SpeciesS. nigriventris
Size4 inches
Lifespan15 years
DistributionCentral Africa
ColorRusty brown
Minimum tank size20 gallons
Place in tankbottom
Care levelBeginner

History and Background

The upside down catfish has been an aquarium anomaly ever since the Ancient Egyptians. The Egyptians were so intrigued by this unusual fish that artworks depicting the upside-down catfish, such as a fish pendant.


The Synodontis catfish family is widely distributed throughout Africa. Specifically, these upside-down freshwater fishes can be found in Central Africa. They are mainly found in the Central Congo River basin, along the banks of rivers characterized by dense vegetation.

Why do upside down catfish swim upside down

Swimming upside down is a trait that produces less wave drag and allows the upside down catfish to swim faster. Additionally, by swimming invertedly the catfish’s gills are close to the surface of the water making it easy for them to obtain oxygen.

The Upside-Down Catfish Swimming Movement

While swimming upside down makes it easier to breathe and lets them swim faster the upside down catfish does have all of the right side up counterparts such as a normal swim bladder and no imbalances in their ears. This makes their inverted position just a quirky feature of these tropical fish.


Swimming upside down is a trait seen in most sea creatures that are from the deep sea.

Do upside-down catfish always swim upside down?

No, this catfish won’t always be swimming in an upside down position.

Can upside down catfish swim right side up?

Yes, they’ll often be seen swimming right side up when it wants to graze along the bottom of the tank.

Are upside-down catfish algae eaters?

They will eat algae, however they are omnivores and should be fed a diet including sinking catfish pellets, insect larvae, and other protein rich foods.


An upside-down catfish swimming through the aquarium plants
(1) An upside-down Catfish Swimming Through The Aquarium Plants

While you may think most catfish are dull because of their lack of coloring, we believe that they’re just letting their inner beauty shine.

What do upside down catfish look like

The adult size of this species is a maximum of 4 inches. Physical features include large eyes, a forked tail, three pairs of barbels, and a large adipose fin. Coloring is a light to rusty brown with dark brown spots.

You’ll notice that the underside of the body is actually darker which is different from other species that swim upright. This is so when they swim upside down at the surface of the water they are camouflage.


There are actually seven species of catfish, which live mostly upside down. Most often, “upside down catfish” is referred to as Synodontis nigriventris. We’ve listed the other six species below.

  • Mystus leucophasis-Asian upside down catfish
  • Synodontis angelicus-spotted upside down catfish
  • Synodontis aterrima-also often mistaken for S. nigriventris in the aquarium trade, however genetic testing proves it as a completely different species
  • Synodontis batensoda-giant upside down catfish
  • Synodontis contracta-big nosed upside down catfish
  • Synodontis nigrita-also known as the false upside down catfish, but commonly sold as S. nigriventris. The difference is only recognizable in mature adults as they are twice the size as S. nigriventris.

How big do upside down catfish get

The maximum size of this animal species is four inches. However, other upside down catfish varieties are often sold mistakenly and can grow from double to quadruple the S. nigriventris size.

Temperament and Tankmates

Bronze Corydoras
Bronze Corydoras Are Good Tankmates For The Upside-Down Catfish

As a peaceful and shy fish the upside down catfish often needs dither fish as tankmates. These are fish that are well suited to bringing this species out of its hole and letting its personality shine through.

Are upside down catfish aggressive?

No, they are quite peaceful species when housed with similarly sized fish. Smaller fish can be eaten by the upside down catfish, and larger, more aggressive fish will cause the upside down catfish to raise its spines which can cause issues if the other fish tries to swallow it.

Will a upside down catfish eat other fish?

Yes, as carnivores the upside down catfish will attempt to eat smaller fish, especially if not fed a proper diet.

How many upside down catfish should be kept together?

These fish are tight schooling fish and you should keep a group of at least four. Keeping them in a school will give the upside down fish confidence and encourage them to explore their habitat instead of hiding.

What fish can live with upside down catfish

Tank mates that are similarly sized and not aggressive fish will do well with this upside down fish.

Top 5 Compatible tank mates

  1. Zebra danios– a popular tank mate in the aquarium hobby because of their ability to get along with most fish. They are about half of the upside down catfish’s size and are unlikely to be eaten.
  2. Dwarf cichlids-Another peaceful species, they are found in a similar natural habitat and will do well with the same water parameters.
  3. Tetras-Colorful and mostly peaceful fish species that will respond well to the upside down catfish care level.
  4. The Corydoras– prime catfish tank mates that will help keep your tank clean and other fish healthy.
  5. Mollies-these fish are good tank mates, are peaceful and can feed on algae on the sides of your tank while the upside down catfish grazes along the bottom.

Top 3 Tankmates to avoid

There aren’t many bad potential tank mates when it comes to upside down catfish as they have a very amicable nature. However, there are a few that you should avoid.

  1. African Cichlids-a bully fish that will likely bat your catfish back and forth whenever it starts swimming upside down.
  2. The Angelfish-despite being a tropical fish, these two species do not do well together due to angelfishes aggressive nature
  3. Neon tetras-this fish is much to small when compared to the upside down catfish size and will likely be swallowed whole

Tank Requirements

Woman Setting Up A Fish Tank
Woman Setting Up A Fish Tank

While these fish are not picky, there are certain requirements you must meet in order to keep them happy and healthy. They will need at least a 20 gallon tank, water heater, and plenty of plants in order to thrive.

Will upside down catfish eat guppies

Yes, due to their size difference upside down catfish will likely eat all guppies in the tank.

How many upside down catfish should be kept together?

These fish respond best when they are kept in groups of 4 to 6.

Tank Size

The minimum tank size for 1 upside down catfish is 20 gallons, with an additional 10 gallons per fish. So for a school of 4 catfish you should count on a tank that is at least 50 gallons. Additionally, when choosing a tank you should find a design that has a wide top and lots of surface area. As upside down catfish spend most of their time upside down they need an aquarium environment that supports their activity level.

Can upside down catfish live in a 5 gallon tank?

No, not only is 5 gallons too small for the bioload of an upside down catfish, it also doesn’t have enough surface area to keep your fish happy.

Water Parameters

Water TypeFreshwater
Water Temperature73-79 F
Water pH6 to 7.5
Water hardness4 to 15 dGH
Tank Size>20 gallons

Tank setup:

When planning tank decorations and setup you should try to replicate the upside down catfish’s natural habitat.

What kind of Substrate is best for upside down catfish

Sand and large, smooth river stones are the best substrate as they will collect algae, but also be a gentle substrate on your catfish’s belly when it decides to spend time along the bottom of the tank.

Should I get a filter

An appropriately sized filter based on your tank size is necessary from proper upside down catfish care and maintenance. Like all fish, they produce more waste than you would think for their size and require pristine water conditions.

Do upside down catfish need a pump

In their natural environment these fish are in a fast moving river environment, and prefer a strong water flow within their aquarium. A pump, while not necessary, will provide additional water flow and increase your fish’s happiness.

Do I really need a Water heater?

As they prefer warmer water temperatures you will likely need a water heater for your upside down catfish tank unless it sits in an extremely warm area of your house where it is able to maintain standard temperatures.

What temperature do upside down catfish like?

Upside down catfish prefer temperatures between 73 and 80 degrees Fahrenheit.

What kind of lighting should I use

Use moderate lighting when illuminating your tank. While the upside down catfish swims at the surface often and receives light from the sun in their native environment they do not like to be blinded with bright LED’s 24/7.

Top 3 Plants for upside down catfish tank

Upside down catfish enjoy a heavily planted tank, especially floating plants and broad leaved plants which allow them to hide under. Additionally, plants with large leaves will allow them to turn upside down and explore the underside of the leaf giving more space for them to swim.

  1. Water lettuce-similar to Amazon frogbit, water lettuce comes in a bright green sheen and has wrinkled leaves. It is fast growing and accepts most water parameters.
  2. Amazon frogbit– a lime green plant that looks sort of like tiny lily pads. They are excellent at helping control nitrates and are useful in tanks that have heavy bioloads. They also provide lots of shade and cover to your fish, especially smaller ones.
  3. Broad leaf anubias– or Anubias Barteri is an excellent plant to add for aquarists who don’t usually keep live plants. It is broad leafed, dark green, and is adaptable to a large range of conditions.

Submerged branches and driftwood are also good additions to your tank as they will provide additional crevices and hides for your catfish to burrow into.

Do upside down catfish need an air pump?

An air pump is probably not necessary for this species unless you have a fast growing plant like water lettuce that is taking up most of the oxygen in the tank.

Do upside down catfish need hiding places?

Yes, having lots of hiding places in your aquarium is vital for your fish’s health and happiness.

Diet and Health

Fish Food
Fish Food

When feeding your upside down catfish, the quality of their is most important. Mimicking the diet your fish would have in its natural habitat is an excellent way to keep your fish healthy.

What do upside down catfish eat?

The upside down catfish diet includes insect larvae, sinking pellets, and algae wafers.

What to feed upside down catfish?

You should feed your upside down catfish a high quality diet that is similar to what they would receive in their natural river systems. Insect eggs, mosquito larvae, vegetables, and other live food is most appropriate for the diet upside down catfish need.


Because this fish spends most of its time upside down on the surface of the water we recommend using slow sinking pellets.

How often to feed upside down catfish

You should feed your fish 1 to 2 times a day, and add supplemental protein twice a week.

How much to feed upside down catfish?

Like most fish you should follow the three minute rule to ensure that you don’t overfeed your catfish. This is where you begin by dropping 2-3 pellets in the water and start a timer. Once your fish has finished all of the pellets add more and repeat until the timer sounds. To feed vegetable matter add the vegetable to the tank and allow it to remain there for at least 2 to 3 hours to give your fish plenty of time to munch on it.


Be sure to remove all uneaten food from the aquarium to prevent it from fouling your water quality.

Common diseases of upside down catfish 

There are no diseases that specifically target upside down catfish, however they are susceptible to most freshwater fish diseases if proper upside down catfish care protocols are not followed. Here are our top three diseases to lookout for when it comes to these fish.

  1. Swim bladder disease-despite their interesting swimming patterns this fish still has air bladder, and because of their peculiar behavior you likely won’t notice if it’s infected. However, if you notice your fish to be bloated, lethargic, or have a loss of appetite this could be signs of this disease. Treatment options include better tank maintenance, and epsom salt, and feeding veggies like shelled peas. If symptoms don’t improve you may need to visit a vet for antibiotics.
  2. Bacterial Infections-because of their long barbels and fins these fish can be expected to get nipped occasionally which can lead to bacterial infections. Treatment includes a broad spectrum antibiotic treatment such as Melafix.
  3. Constipation-if you’re feeding your fish a diet that is too high in protein you might notice that it’s not having regular bowel movements. This can be a sign that it’s constipated. The main course of treatment is the addition of fiber to its diet, mainly in the form of shelled peas.

How long do upside down catfish live

The upside down catfish lifespan is fairly long, averaging around 15 years in captivity. The long life expectancy deters some aquarists as they don’t want to commit that long, but we think these are some of the most quirky and personable fish you can have! 

Where should you not touch a catfish?

You should not try to touch your upside down catfish anywhere as this will likely cause stress for the fish. As a very shy fish already, it is not likely that you will get close enough to your upside down catfish to touch it anyways.

Many people are tempted to touch upside down fish because they think they are dead or sick. However, now that you know that they aren’t you shouldn’t be concerned.


While not as difficult as breeding the Chinese algae eater, very few home aquarists have been able to successfully breed this species.

Can you breed an upside down catfish?

There has been limited success breeding this fish in captivity, especially without hormone injections. Most species you see in the aquarium hobby have been wild caught.

How to breed an upside down catfish?

To encourage breeding you must first begin feeding your mating pair a high quality diet and produce a tank that has many cave shelters and plants. Breeding tank water parameters should be a water temperature of 75-80, a pH of 7 and water hardness of 10 dGH. Males and females should be separated until the breeding tank is ready and then put together.

In the commercial process this is when the reproduction hormone is injected. However, in a home aquarium you can increase breeding success by using moderately soft water and filling a watering can with cold water then pouring it into the tank to mimic spring rains.

If the spawning process is successful females can lay up to 450 eggs, which are generally placed along the roof of a cave shelter. Eggs will hatch in two to three days, and become free swimming roughly 4 days after that.

Is the upside down catfish for you? 

If you’re looking for a peaceful and quirky natured fish for your freshwater aquarium we think this one is a top choice!


Our final thoughts on this species is that the upside down catfish can make a valuable addition to any aquarium.

Featured Image – John P. Friel Ph.D., CC BY 4.0, via Wikimedia Commons
(1) Gourami Watcher, CC BY-SA 3.0, via Wikimedia Commons

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