The Congo Tetra (Phenacogrammus interruptus) is one of the most striking and elegant freshwater schooling fish available in the aquarium hobby. Native to the Congo River Basin in Central Africa, this species is prized for its iridescent, rainbow-like coloration, graceful movement, and peaceful nature, making it an exceptional choice for large community aquariums.
Congo Tetras have elongated, streamlined bodies that shimmer with hues of blue, green, gold, and violet as light reflects off their scales. Males are especially vibrant, developing long, flowing fins with delicate white edging and a dramatic lyre-shaped tail that adds to their refined appearance. Females are slightly smaller and less colorful but still display a subtle metallic sheen. When kept in proper conditions and in groups, their colors intensify and their natural schooling behavior becomes a stunning visual display.
Peaceful and social by nature, Congo Tetras thrive in groups of at least 6–8 individuals, though larger schools are strongly recommended to reduce shyness and encourage confident swimming. They do best in spacious aquariums with open swimming areas, paired with live plants, driftwood, and subdued lighting to mimic their natural river habitat. Their calm temperament makes them excellent tank mates for other peaceful, similarly sized fish.
Congo Tetras are omnivores and accept a wide variety of foods. A balanced diet of high-quality flake or pellet foods, supplemented with frozen or live options such as brine shrimp, daphnia, and bloodworms, will support vibrant coloration and overall health.
Ideal Water Parameters
-
Temperature: 73–82°F (23–28°C)
-
pH: 6.0–7.5 (slightly acidic to neutral)
-
Hardness: 3–18 dGH (soft to moderately hard)
-
Tank Size: 40 gallons minimum (larger preferred for schools)
-
Water Flow: Gentle to moderate
-
Lighting: Moderate to subdued
With proper care, stable water conditions, and a well-planted aquarium, Congo Tetras can live 5–8 years. Their shimmering colors, peaceful demeanor, and active schooling behavior make them a standout species and a favorite centerpiece schooling fish for intermediate and experienced aquarists alike.
