The Blue Tetra is a small schooling fish with a vivid neon-blue sheen from Peruvian rivers, undemanding and ideal for a tropical community aquarium.
Overview
Boehlkea fredcochui, or the Blue Tetra, is an elegant schooling fish from the family Characidae, found in tributaries of the Amazon in Peru. In the wild, it inhabits slow-flowing forest streams with soft water and shaded bottoms covered in fallen leaves.
The standout feature of this species is a vivid neon-blue stripe running along the entire body from head to tail. Under proper lighting, a school of Blue Tetras creates a stunning visual effect. The body is elongated, slightly compressed laterally, and semi-transparent with a silvery sheen. Adults reach 4–5 cm and live 3–5 years. This is an active daytime fish with an exceptionally peaceful temperament, making it an ideal community tank resident.
Tank Requirements
A school of 8–10 fish suits an aquarium from 60 liters. Water parameters: temperature 22–28°C, pH 5.5–7.5, hardness GH 2–12. The Blue Tetra prefers soft, slightly acidic water — in hard water, the coloration fades noticeably.
A dark substrate is essential for bringing out the maximum blue coloration. On a light substrate, the fish look washed out. Plant the tank densely with live plants, leaving the central area open for swimming. Driftwood and fallen oak or Indian almond leaves help recreate natural biotope conditions and slightly acidify the water. Keep lighting subdued or diffused — floating plants handle this perfectly. Flow should be moderate to gentle.
Feeding and Diet
In the wild, Boehlkea fredcochui feeds on small insects, their larvae, micro-crustaceans, and plant matter that falls into the water. In the aquarium, the fish is undemanding. High-quality flakes or small pellets for tropical fish form the staple diet.
Regularly supplement dry food with frozen or live brine shrimp, daphnia, cyclops, and bloodworms — this enhances coloration and supports overall health. Feed twice daily in small portions consumed within 1–2 minutes. The Blue Tetra has a small mouth, so food must be fine-grained. Overfeeding is undesirable — uneaten leftovers quickly foul the water in a soft-water tank.
Care and Maintenance
Weekly water changes of 20–25% are the foundation of Blue Tetra health. Use gentle filtration without strong flow — a sponge filter or external canister filter with a spray bar works ideally. Ammonia and nitrites must be strictly at zero, nitrates below 20 mg/l.
The Blue Tetra is sensitive to sudden changes in water parameters, so perform water changes gradually. Under stable conditions, the fish rarely falls ill. Main threats include ich from temperature drops and bacterial infections from degraded water quality. Monitor coloration — a fading blue sheen is the first signal of stress or health problems.
Compatibility
The Blue Tetra is one of the most peaceful aquarium fish. Keep in schools of at least 8 — in small groups, the fish become skittish and lose color intensity. Excellent tankmates include other small peaceful tetras: Black Neon Tetra, Glowlight Tetra, Flame Tetra, as well as small Pygmy Corydoras and rasboras.
Avoid keeping with large or aggressive fish — cichlids, large barbs. Also avoid active fin-nippers. The Blue Tetra fits perfectly into a South American biotope aquarium with subdued lighting and soft water.
Breeding
Breeding Boehlkea fredcochui at home is challenging (difficulty 4 out of 5). Prepare a separate spawning tank of 20–30 liters with very soft water (GH up to 4, pH 5.5–6.5) and a temperature of 26–27°C. Place fine-leaved plants or a spawning grid on the bottom to protect the eggs.
The Blue Tetra is an egg scatterer, releasing eggs among plants. Remove the parents immediately after spawning — they readily eat their own eggs. The eggs are small and light-sensitive — keep the spawning tank darkened. Larvae hatch in 24–36 hours, and after 3–4 days the fry begin free-swimming. Starter food is infusoria and microworms; after a week, transition to baby brine shrimp. Fry grow slowly and require stable water parameters.