Mochokidae

Upside-down Catfish

Synodontis nigriventris

The Upside-down Catfish, scientifically known as Synodontis nigriventris, belongs to the family Mochokidae. Its name accurately reflects the main characteristic of this species: it constantly swims upside down. It is thanks to this unusual behavior, as well as its peaceful nature and unpretentiousness, that this catfish has gained widespread popularity among aquarists worldwide.

Tank
from 70 L (18 gal)
Temperature
24 – 28 °C (75 – 82 °F)
Size in aquarium
6 – 10 cm (2.4 – 3.9 in)
Acidity
pH 6–8
Natural rangeRange on the map
  • Congo River Basin
  • Middle Congo River
  • Cameroon
  • Democratic Republic of the Congo
  • Republic of the Congo

Tank conditions

Plan the tank stocking
Temperature
24 – 28 °C (75 – 82 °F)
Water pH
Slightly acidic (6) – Slightly alkaline (8)
Water dH
Soft (5) – Very hard (19)
Water salinity
no salt (freshwater)
Size in aquarium
6 – 10 cm (2.4 – 3.9 in)
Lifespan
15 years
Temperament
Peaceful (regular)
Toward small fish
not a predator
Required aquarium volume
from 70 L (18 gal)
Lighting
dimmed
Substrate
sandy (regular, light)
Water flow
weak
Swimming level
near the bottom
Feeding
Any (universal)
Keeping
Schooling usually from 5–6 individuals and more
  • Lifespan. A lifespan to expect under good care, not a measured value: it depends heavily on tank volume, water quality and diet — and for selectively bred forms, on their origin as well.
  • Toward small fish. Based on the Predators category in the catalog or the temperament in the species parameters. “A risk to small fish” means the species is not a predator by habit, yet will swallow any fish that fits in its mouth.
  • Required aquarium volume. This is a husbandry recommendation, not a measured value: the volume depends on the keeping mode (schooling (usually from 5–6 individuals and more)), footprint, decor and tank mates.

Care and keeping

Description

This fish is distinguished by its modest size. Adult males reach only about 6 cm in length, while females grow larger, up to 8–9 cm. The Upside-down Catfish has an elongated and slightly flattened body, characteristic large eyes, and three pairs of barbels located around its mouth. Its coloration is gray-brown, with several dark spots distributed over its body. Its belly is dark, while its back is significantly lighter.

Habitat

Originating from Africa, this species inhabits numerous tributaries of the Congo River basin, concentrating primarily in its middle reaches. It prefers to settle in areas of rivers abundant with dense vegetation and located under the thick canopy of a humid tropical forest.

Behavior and Compatibility

This is a peaceful, schooling fish that gets along well with most calm, non-aggressive species. Optimal companions will be fish from the same habitat, such as African tetras. There are no conflicts observed within its own species.

Care and Maintenance

To set up the aquarium, several essential components must be considered: it is recommended to use a soft, dark substrate, such as sand, as well as groups of rooted and floating plants, such as Anubias and Echinodorus. It is also important to provide numerous shelters using snags, intertwined tree roots, or branches. A harmonious combination of these elements will create a favorable habitat that fully meets the needs of the Upside-down Catfish. It is best to fill the aquarium with soft to medium-hard water. As for the hydrogen index (pH), it can range from slightly acidic to slightly alkaline. This species is completely undemanding regarding the hydrochemical composition of the water and thrives in a wide range of general hardness (dGH) and pH values. Standard aquarium equipment includes a filter, heater, aerator, and a lighting system set to a low light intensity. Regular maintenance, in addition to daily feeding, includes cleaning the substrate and glass as needed, weekly water changes of 15–20% of the volume with fresh water, and constant monitoring of its quality.

Diet

Regarding feeding, this catfish is undemanding, readily accepting all types of food: dry (in the form of flakes or pellets), live, and frozen. It is important that the food floats, as it prefers to feed from the surface. It is recommended to feed the fish 2–3 times a day, offering an amount of food they can consume within 5 minutes.

Breeding and Reproduction

Breeding the Upside-down Catfish in a home aquarium is possible, although detailed and reliable information on this is quite rare. In their natural habitat, spawning occurs during the rainy season when fish migrate to flooded forest areas. This indicates that the stimulus for reproduction is a change in external conditions – specifically, the gradual addition of very soft, cool water. To implement such significant changes, it is advisable to use a separate tank – a breeding aquarium. There is conflicting data regarding the egg-laying site: they are either attached to a substrate of dense vegetation or placed in secluded spots under driftwood. One adult female can lay up to 450 eggs. The fry hatch on the 4th day and initially swim vertically. Only by 7–8 weeks of age do they transition to the species' characteristic upside-down swimming.

Diseases

In a well-balanced aquarium ecosystem, disease outbreaks are extremely rare. Health problems only begin in severely neglected cases, when keeping conditions significantly deteriorate, for example, due to a lack of regular cleaning and water changes, overcrowding of the aquarium, or feeding with poor-quality or monotonous diets.

How to choose

When purchasing, choose active individuals that show no signs of lethargy and have no visible skin damage. It is important to inspect the fish for the absence of ulcers, white spots, or film, which indicate diseases. Avoid specimens with an unnaturally sunken belly or damaged fins. In the store, catfish may hide, so it is worth asking an employee to reveal them to assess their health and plumpness. Refuse to purchase if dead individuals are found in the aquarium with the fish or if the keeping conditions are clearly unsatisfactory, as this increases the risk of hidden infections. A healthy catfish should have clear coloration and display natural curiosity for the species when feeding.

Compatibility

There are no pair reviews for this species yet — check tankmates in the matcher.

All tankmates

Plants and this fish

Matching water does not mean the plant will stay intact.

Frequently asked questions

The essentials: size, tank volume, water parameters and care

How big does Upside-down Catfish get?

An adult reaches 6–10 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.

What size aquarium does Upside-down Catfish need?

The recommended volume is 70 L. A smaller tank speeds up nitrate build-up and raises stress levels.

What water parameters does Upside-down Catfish need?

Temperature 24–28 °C, pH 6–8, hardness 5–19 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.

How long does Upside-down Catfish live?

Around 15 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.

Is Upside-down Catfish aggressive?

Temperament: peaceful (regular). Keep this in mind when choosing tank mates.

How many Upside-down Catfish should be kept together?

Recommended setup: schooling (usually from 5–6 individuals and more). Ignoring this is a common cause of stress and disease.

What does Upside-down Catfish eat?

Diet type: any (universal). Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.

What is the scientific name of Upside-down Catfish?

The scientific name of the species is Synodontis nigriventris, family Mochokidae. It also appears in the literature as: Synodontis nigroventris.

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Other scientific names and conservation status

Other scientific names
Synodontis nigroventris
Categories
Catfish
Conservation status
Least concernLC