Black Phantom Tetra

Hyphessobrycon megalopterus, the Black Phantom Tetra, is native to the upper Guaporé River basin in Brazil and Bolivia, inhabiting slow-moving, tannin-stained blackwater environments. Its coloration is subtly stunning — a translucent grey-silver body marked by a bold black humeral spot encircled by a metallic silver ring. Males are darker overall and develop impressively large, flowing dorsal and anal fins, which they use in ritualised parallel swimming displays to establish dominance hierarchies without actual combat. These male-to-male displays are fascinating to observe and add considerable life and interest to the aquarium. Females are easily distinguished by their reddish-orange coloration on the ventral fins and body, making this a sexually dimorphic and visually interesting species. The Black Phantom Tetra is peaceful toward all other species and does not fin-nip, making it a reliable community fish. It thrives in soft, slightly acidic water replicating its blackwater origin but adapts well to neutral conditions. Planted aquariums with dark substrate and some shading bring out the best contrast in its coloration. A school of 8 or more individuals allows natural display behavior and confident movement.

Tank Setup A 60-liter aquarium is suitable for a school. Use dark substrate and include driftwood and Indian almond leaves to create blackwater conditions with natural tannin staining. Dense planting with open swimming corridors encourages natural schooling behavior. Avoid bright, harsh lighting.

Water Parameters Maintain pH 6.0–7.5, temperature 22–28°C. Soft, slightly acidic water is preferred but this species adapts to neutral conditions. Perform 25% weekly water changes. Add peat filtration or Indian almond leaves to soften water and lower pH naturally if needed.

Filtration A sponge filter or gentle internal filter prevents strong currents. This species inhabits slow-moving water in the wild. Effective biological filtration is essential for water quality; clean mechanical media regularly without disturbing the biological colony.

Diet Feed quality flake food, micro-pellets, frozen baby brine shrimp, daphnia, and bloodworms. Vary the diet to maintain health and enhance color. Feed twice daily in small amounts. Condition breeding adults with live foods.

Tankmates Ideal with other small, peaceful South American tetras, rasboras, dwarf corydoras, small loaches, and peaceful dwarf cichlids such as Apistogramma. Avoid boisterous or nippy species. Males may display to each other with fin-spreading but do not cause injuries.

Breeding Egg scatterers that spawn among fine-leafed plants or spawning mops. Use a dedicated breeding tank with very soft, acidic water and dim lighting. Remove parents after spawning. Eggs hatch in 24–36 hours; free-swimming fry feed on infusoria initially, then baby brine shrimp after several days.