Congo Tetra
Congo Tetra – Phenacogrammus interruptus
The Congo Tetra (Phenacogrammus interruptus) is a popular freshwater aquarium fish known for its iridescent scales, flowing fins, and peaceful nature. Originating from the Congo River Basin in Africa, these fish thrive in soft, slightly acidic to neutral water with plenty of plants and open swimming space.
Quick Overview
Common Names: Congos, Congo Tetra
Scientific Name:Phenacogrammus interruptus
Popularity: Highly popular in community aquariums
Adult Size: 3 – 3.5 inches (7.5 – 9 cm)
Lifespan: 3 – 5 years
Sexing: Males are larger and more colorful, with longer, flowing fins
Temperature: 73 – 82°F (23 – 28°C)
pH Range: 6.0 – 7.5
Water Hardness: 4 – 18 dGH
Nature: Peaceful Communtiy Fish
Natural Habitat & Origin
The Congo Tetra originates from the slow-moving, heavily vegetated waters of the Congo River Basin. They are found in soft, tannin-rich water with plenty of submerged plants and driftwood.
Appearance & Size
Congo Tetras are known for their shimmering, rainbow-colored scales that reflect blue, gold, and violet hues. Their long, flowing fins give them an elegant appearance, especially in males. They are larger than the more common tetras, therefore, they need larger-sized aquariums once fully grown.
Tank Requirements
Minimum Tank Size: 30 gallons (~120L)
Preferred Tank Setup: Planted aquarium with plenty of swimming space
Substrate and Decorations: Dark substrate, driftwood, and live plants enhance their colors
Tank Mate Options: Peaceful community fish such as Rasboras, Corydoras, and Gouramis
Avoid: Aggressive or fin-nipping species like Tiger Barbs
Water Parameters & Conditions
Temperature: 73 – 82°F (23 – 28°C)
pH Range: 6.0 – 7.5
Water Hardness:4 – 18 dGH
Filtration & Oxygenation: Moderate to strong filtration with good water movement
Lighting: Moderate lighting enhances their iridescent colors
Diet & Feeding
Congo Tetras are omnivores and require a varied diet for optimal health.
Recommended Foods: High-quality flakes, pellets, live and frozen foods such as bloodworms, brine shrimp, and daphnia
Feeding Frequency: 2 – 3 times daily in small portions
Behaviour & Compatibility
Congo Tetras are peaceful schooling fish that thrive in groups of six or more.
Good Tank Mates: Gouramis, Corydoras, Rainbowfish, and peaceful Tetras
Avoid: Fin-nipping fish like Tiger Barbs or overly aggressive species
Breeding
Breeding Congo Tetras can be challenging, as they require soft, slightly acidic water and dim lighting to encourage spawning. A suitable breeding setup includes a 20-gallon tank with a sponge filter and fine-leaved plants, providing a safe environment for egg scattering.
During the breeding process, males perform an elaborate courtship display before females release their eggs among the plants. The eggs will hatch in about 6 to 7 days. The fry initially need infusoria before transitioning to baby brine shrimp for proper growth and development.
Common Health Issues & Prevention
Congo Tetras are generally hardy fish, but they can be susceptible to stress-related diseases, especially in poorly maintained aquariums. Common health issues include Ich, which appears as white spots on the skin and causes scratching and lethargy. Another common issue is fin rot, which leads to frayed and discolored fins due to bacterial infections, and other bacterial illnesses that can develop in response to poor water quality or stress. If left untreated, these diseases can weaken the fish’s immune system and lead to more severe complications.
To prevent these issues, it’s crucial to maintain clean and stable water conditions. This can be done by performing regular water changes and using a high-quality filtration system. Avoiding sudden fluctuations in temperature, pH, and water hardness is essential, as Congo Tetras are sensitive to abrupt parameter shifts. Additionally, providing a stress-free environment and a well-balanced diet will help keep them healthy and resilient against disease. Observing your fish daily for signs of illness allows for early intervention, increasing the chances of a full recovery.
Fun Facts
– Male Congo Tetras develop extended, trailing fins as they mature.
– Their iridescent colors become more vibrant under proper lighting and a high-quality diet.
– Congo Tetras are best kept in a school of at least six to reduce stress and bring out their natural behaviors.