Congo Tetra Complete Care Guide

Congo Tetra

The Congo Tetra, Phenacogrammus interruptus, comes from the middle of the Congo River basin. The Congo River is also known as the ZaireRiver. In total flow, it is the second biggest river in the world.

The Congo Tetra is found in the Democratic Republic of the Congo, and maybe in the Republic of the Congo.


OriginCongo River, Zaire
Adult Size3 to 3 ½ inches
SocialPeaceful schooling fish
Lifespan3 to 5 years
Tank LevelAll levels
Minimum Tank Size40 gallons
BreedingEgg layer
pH6.0 to 6.5
Hardness3 to 18 dGH
Temperature73.0 to 82.0 F (22.8 to 27.8 C)

Congo Tetra Size

The Congo Tetra is one of the largest tetras. The male will grow to 8 cm (3 inches) while the female will reach 6 cm (2.5 inches).

Water Conditions

The Congo Tetra will tolerate a good range of conditions. A pH of between 6.0 and 8.0 is all right. They do not mind a reasonable amount of hardness; 5-19 dH is suitable for maintaining the adults.

The Congo Tetra is a tropical fish and needs water that does not get cold. An aquarium heater with the thermostat set on between 23 and 26 degrees C (between 73 and 79 degrees F) is recommended.


In the wild, the Congo Tetra is an omnivore, eating insect larvae like mosquitoes, small crustaceans like Daphnia, small worms and algae.

In an aquarium, it will eat normal dried fish food readily. A high protein food is to be prefered. If possible this should be supplemented with live food like Daphnia and frozen food like blood worms and brine shrimp.

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The Congo Tetra is a schooling fish, and generally a minimum of five is recommended. However, some people have reported that they have kept a pair of these fish and they act as if they are not stressed.

It is a bigger fish than most tetras and I do not recommend keeping it with the smallest tetras like the Adonis or the Neon tetras.

Most of the tetras and the more peaceful barbs are good companions for them. I have kept Congo Tetras with a Siamese Fighting Fish and Guppies without trouble, but I suspect that this would not always happen, and I suggest caution in keeping slow-moving long finned fish with Congo Tetras.

The Congo Tetra is an good community fish.

You should also avoid large, aggressive fish like many of the cichlids with Congo Tetras.


The Congo tetra can be bred either in a pair or in a school. It is probable that in the wild they are mainly school breeders. They readily breed and will often lay eggs in a community aquarium but the owner will normally not be aware of this.

If deliberately setting out to breed this beautiful fish, the breeding tank should have soft, acidic water. Some people use a peat substrate. As with many fish, the Congo Tetra will often spawn when the morning light falls on the aquarium. Unlike many tetras, they seem happy spawning in a brightly lit aquarium.

About 300 eggs are laid per female; they are light brown in colour and would be camouflaged against a peat substrate. This suggests the possibility that this type of substrate is common in their natural habitat. The eggs hatch in about 6 days.


The male Congo Tetra has significantly longer fins than the female. In addition to this general difference, the centre of the male’s tail is longer than the rest of the tail. The dorsal fin of the male reaches to the tail fin.

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Congo tetra tank mates

There are several options when choosing a Congo Tetra tank partner.

These fish are a great addition to peaceful tanks, and fish of a similar size are passive and gentle.

Best tank friends are, of course, other Congo tetras. We recommend getting a team of no less than 6.

The more Congo tetra you have in the tank, the better. Make sure your fish tank is large enough and has plenty of room to swim.

Here are other species that make good Congo Tetra tank mates:

  • Corydoras
  • Rainbowfish
  • Dwarf Cichlids (aka Apistogramma)
  • Celestial Pearl Danio
  • Ember Tetras
  • Mollies
  • Neon Tetras
  • Elephant Nose Fish
  • Chili Rasbora
  • Rummy Nose Tetras
  • Platies
  • Swordtails
  • Barbs

Diseases To Watch Out For

Congo tetras are at risk of many common fish diseases. However, they are not subject to any particular problem.
The most common disease you may have to deal with is Ich. This is a side effect of stress and can be fatal. Fortunately, the treatment is relatively simple with isolation and the-counter products.
By being vigilant about water conditions and overall tank maintenance you can prevent Ich as well as other diseases.
The important thing to remember is that diseases are always easier to prevent than to cure.

Raising the Fry

The babies seem ready to eat as soon as they hatch. They are big enough for newly hatched Brine Shrimp, finely screened Daphnia, rotifers or similar sizes food.

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Least Concern

The IUCN Red list regards the Congo Tetra as a species of least concern although it has no information about how whether or not the population is decreasing.

Pest Fish

Although I am not aware of the Congo Tetra having become a problem, we should always avoid our pets getting into ecosystems that they are not native to.

Other Scientific Names

The accepted scientific name is Phenacogrammus interruptus (Boulenger, 1899). Other names that have been used are Micralestes interruptus Boulenger, 1899, Hemigrammalestes interruptus (Boulenger, 1899) and  Alestopetersius interruptus (Boulenger, 1899).

Check out additional fish profiles for more further information on other freshwater fish.