Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Synodontis nigriventris

Upside down catfish

Upside down catfish, Synodontis nigriventrisUpside down catfish, Synodontis nigriventris
Photos by Andy Rapson


Synodontis: Greek, syn, symphysis = grown together + Greek, odous = teeth

General Notes:

Synodontis nigriventris is an unusual but peaceful odd ball of a fish and can be added to any peaceful community tank with small and medium sized fish. In Caves and bogwood are important to these fish because when resting upside down they prefer to have a solid surface against them. Like lots of other catfish they can be secretive especially when first introduced but once settled they will show themselves a little more although their main period of activity will be after the lights have gone out because they are essentially nocturnal. In 1976 a study was undertaken to try to discover more about why they choose to spend so much time upside down. There swim bladder is entirely normal and their inner ear is the same as any other fish but the nerves leading to the balance organ of the ear was found to be different than in other fish which gives a clue about how they do it but not why they do it.


Omnivore, in the wild Synodontis nigriventris eats crustaceans, worms, insect larva and some vegetable matter. In captivity they are quite unfussy and will accept a diet of flake food, catfish pellets and live or frozen food such as blood worms. If you decorate their tank with lots of stones and bogwood they will get in to all the nooks and crannies looking for food which is out of reach of other fish.


There are no reliable external differences between the sexes.


Synodontis nigriventris is one of the few Synodontis to have been bred by hobbyists. There are a couple of sketchy reports about accidental breeding where the fish spawned in a pipe and another report where the fish spawned in a gravel depression.

Wild status

Synodontis nigriventris is widespread without major threats throughout central Africa it has also been introduced to the Philippines but less is known about the population there.

Information at a glance

pH: 6 - 8
dGH: 5 - 12
Temperature: 22 - 26°C (72 - 79°F)
Diet: Omnivore
Size: 10cm (4in)
Min tank size: 100 litres
Difficulty level: Easy
Aquarium type: Community
Swimming level: Lower

Distribution and habitat

distribution map for Upside down catfish, Synodontis nigriventris

Origin: Africa: middle Congo River basin, including Pool Maleboand drainages of the Kasai.

Habitat: Slow moving water amongst heavy vegetation.


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Mochokidae
Genus: Synodontis
Species: S. nigriventris

Common name:
Upside down catfish

Synonyms: -