Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Phenacogrammus interruptus

Congo tetra

Congo tetra, Phenacogrammus interruptusCongo tetra, Phenacogrammus interruptus
Photos by Andy Rapson


Phenacogrammus: Greek, phenax, -akos = deceptive + Greek, gramma = letter, signal

General Notes:

Congo tetras despite being quite large for a tetra are quite timid fish. They should be kept in a shoal of at least six individuals and only ever be housed with other peaceful fish. Their colours will show to their best when the fish is housed under subdued lighting and using a dark substrate. Some plant thickets or other hiding places will help the fish to feel secure and behave in a natural way.


Congo tetras are easy to feed on a mixed diet of flake food, live or frozen food, freeze dried food.


The sexed are easy to differentiate. Adult males have long ray extensions to their tail dorsal and anal fins and are both larger and more brightly coloured than the females.


Being quite large and very active means that Congo tetras need a lot of space to exhibit their natural behaviour. Once settled and well fed the fish will spawn regularly in a community tank but the eggs will be eaten both by the other fish and even the parents. In order to breed these fish it will be necessary to use a separate spawning tank and to remove both parents after spawning. Congo tetras are egg scatterers and the parents show no interest in their brood except as a source of food. Like a lot of other tetras the eggs and fry are light sensitive so the tank should be left unlit and out of direct light or the hatch rate will be lowered.

Wild status

Congo tetras are still relatively common in the wild and are not under any immediate threat.

Information at a glance

pH: 6.4 - 8
dGH: 4 - 18
Temperature: 24 - 27°C (75 - 81°F)
Diet: Omnivore
Size: ?cm (?in)
Min tank size: 200 litres
Difficulty level: Easy
Aquarium type: Community
Swimming level: Middle

Distribution and habitat

distribution map for Phenacogrammus interruptus

Origin: Africa: Middle Congo basin.

Habitat: Fresh water. Congo river and its tributaries.


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes.
Family: Alestidae.
Genus: Phenacogrammus
Species: P. interruptus (Boulenger, 1899)

Common name:
Congo tetra

Synonyms: Alestopetersius interruptus, Hemigrammalestes interruptus, Micralestes interruptus