The Congo tetra (Phenacogrammus interruptus) is a highly popular, vibrant freshwater schooling fish native to the
Congo River Basin in Africa. Renowned for its spectacular, rainbow-like iridescent scales and long, flowing fins, it serves as a stunning centerpiece fish for larger community aquariums.
Appearance & BehaviorRainbow Luminescence: Bodies display shimmering shades of blue on top, red and gold through the middle, and violet-blue on the belly.
Flowing Fins: Mature males develop elaborate, feathery grayish-violet tail fins with white edges and extended middle rays.
Sexual Dimorphism: Males are larger (up to 8–10 cm), more colourful, and have longer fins, while females are smaller, duller, and plumper when holding eggs.
Schooling Nature: They are active, peaceful, and must be kept in groups of at least 6 to 8 individuals to reduce stress and bring out their best colours.
Aquarium Care RequirementsTank Size: Minimum of 100 to 120 litres (30 gallons) to accommodate their size and active swimming style.Water Parameters: Temperature of 23–28°C, pH of 6.0–7.5, and soft, clean water. They are sensitive to poor water quality, so regular water changes are required.Environment: Prefer dark substrates, dense perimeter planting (like Anubias or Java fern), and floating plants to create the subdued lighting they favor.Diet: Omnivorous eaters that thrive on high-quality flakes, pellets, and regular supplements of live or frozen brine shrimp, daphnia, and bloodworms.
Tank Mates Congo tetras are peaceful but large and fast-moving, so they should not be housed with aggressive fish or notorious fin-nippers. Ideal tank mates include other peaceful tetras (like Cardinals), rainbowfish, Corydoras catfish, livebearers, and dwarf cichlids.
