Blue Tetra

Boehlkea fredcochui, the Blue Tetra or Cochu's Blue Tetra, is a subtly magnificent small characid native to the upper Amazon and its blackwater tributaries in Peru. The entire body displays a striking blue metallic iridescence that intensifies under side-lighting, shifting from steel blue to turquoise depending on the viewing angle. Females tend to be slightly plumper when in breeding condition, but both sexes share the beautiful metallic coloration. The Blue Tetra is less commonly available in the hobby than species like the neon tetra, but it is a rewarding find for aquarists seeking something distinctive. It inhabits slow-moving, tannin-rich blackwater environments where water is soft, acidic, and heavily stained. In captivity, it adapts reasonably well to neutral water but colors best and thrives most in soft, acidic conditions that replicate its natural habitat. The Blue Tetra is peaceful and undemanding, making it suitable for nano to medium planted aquariums. A school of 8 or more produces the best display, with the collective blue shimmer creating a captivating visual effect in a well-planted setup with dark substrate.

Tank Setup A 60-liter aquarium is ideal for a school of 8–10. Create a blackwater biotope setup with dark substrate, driftwood, Indian almond leaves, and dense planting. The tannin-stained water both replicates the natural environment and enhances the blue coloration. Floating plants that filter overhead light are recommended.

Water Parameters Maintain pH 5.5–7.5, temperature 22–27°C, and soft water. For optimal health and color, target pH 6.0–6.5 and soft water below 8 GH. Peat filtration or Indian almond leaves achieve this naturally. Perform 25% weekly water changes with soft water.

Filtration Gentle filtration is essential — this species inhabits slow-moving water. A sponge filter or canister with diffused outflow is ideal. Biological filtration should be mature and stable. Avoid strong current, which stresses this species.

Diet Feed quality micro-pellets, fine flake food, frozen or live baby brine shrimp, micro-worms, and daphnia. Like most small tetras, this species has a tiny mouth requiring appropriately sized foods. Feed twice daily in small, measured portions.

Tankmates Compatible with other small, peaceful tetras, dwarf corydoras, small rasboras, pencilfish, and peaceful dwarf cichlids. Avoid any boisterous or nippy species. The Blue Tetra is delicate in personality and does best in calm, well-maintained community tanks.

Breeding Egg scatterers requiring very soft, acidic water for successful reproduction. Spawning is triggered by reduced temperature, dim lighting, and conditioning with live foods. Use a heavily planted breeding tank. Remove parents after spawning; eggs hatch in 24 hours. Feed fry infusoria and then baby brine shrimp.