Columbian Tetra (Hyphessobrycon columbianus)

Hyphessobrycon columbianus, the Columbian Tetra, is a robust and visually striking tetra from the northwestern rivers of Colombia (particularly the Acandí River basin, near the border with Panama). It stands apart from most tetra species in its combination of larger adult size (up to 7 cm), bold colouration, and energetic swimming behaviour.

The colour scheme is distinctive: a metallic steel-blue to silver-blue body with a deep red-orange caudal fin that transitions to red in the unpaired fins. Adult males in breeding condition display more vivid red-orange in the fins, and the body takes on a deeper blue iridescence. The combination of blue and red-orange makes the Columbian Tetra particularly striking in large groups.

Columbian Tetras are hardy and adaptable, tolerating a wide range of water conditions. They are more robust than many sensitive tetra species, making them suitable for a wider range of community setups including those with harder, more alkaline water than is typical for South American species.

However, the Columbian Tetra shares the fin-nipping tendencies common to many larger tetras — particularly in small groups. Keeping groups of eight or more significantly reduces this tendency. They are not suitable for tanks with very slow, long-finned fish.

Tank Setup: A minimum 100-litre aquarium for a school of eight. Moderate to strong water flow, open mid-water swimming space, and plants along the sides and background. Good filtration. A tight lid — active swimmers can jump.

Water Parameters: Temperature 22–28°C; pH 6.0–8.0; GH 5–20 °dH; KH 3–12 °dH. Exceptionally adaptable — suitable for moderately hard Belgian tap water without treatment. One of the hardier tetras in terms of water chemistry tolerance.

Feeding: Omnivore. Accepts quality flake, pellets, frozen bloodworm, brine shrimp, and Daphnia. Feed two to three times daily. Larger mouths than most tetras — standard community flake is appropriate.

Tank Mates: Best with other medium-sized, robust, active fish: barbs, danios, medium tetras, corydoras, loaches, and rainbowfish. Avoid slow, long-finned fish (Bettas, Angelfish) and very small nano fish.

Behaviour: Active, mid-water schooling fish. Groups of 8+ are most well-behaved. Less fin-nipping when properly grouped. Males display with colour intensification. Fast and energetic swimmers.

Health: Hardy and disease-resistant. Tolerates a wide range of conditions. Weekly 25% water changes recommended. Rarely ill in appropriate conditions.