Black Phantom Tetra (Hyphessobrycon megalopterus)

Hyphessobrycon megalopterus, the Black Phantom Tetra, is a beautiful and distinctive tetra from the upper Madeira River basin in Bolivia and Brazil. Males are particularly striking, displaying a pale silvery to bluish-grey body with a prominent black shoulder humeral spot and dramatically elongated, jet-black dorsal and anal fins — creating an elegant, contrasting silhouette unlike most other tetras.

Females differ notably from males in colouration — they retain the black shoulder spot but display reddish colouration in the pelvic and anal fins and a redder overall hue, making sexing straightforward once fish reach maturity. This sexual dimorphism is more pronounced than in most tetra species.

In the wild, Black Phantom Tetras inhabit slow-moving blackwater streams and flooded forests with very soft, acidic, tannin-stained water. They are found in the upper Paraguay and Madeira River drainages of Bolivia and western Brazil. In captivity, they are considerably more adaptable than their blackwater origin suggests, tolerating moderate water hardness without issues.

The Black Phantom Tetra is a classic planted aquarium species — the silver-black coloration contrasts beautifully with green plant backgrounds. It pairs naturally with its close relative the Red Phantom Tetra (Hyphessobrycon sweglesi) to create a dramatic red-and-black colour combination that aquascapers have used to stunning effect.

Tank Setup: A minimum 60-litre aquarium for a school of eight. Dense planting with dark background, open mid-water swimming space, and dark substrate enhance the contrast of the black fins. Gentle to moderate flow. Tannin-stained water (Indian almond leaves, peat) benefits colour.

Water Parameters: Temperature 22–28°C; pH 5.5–7.5; GH 2–15 °dH; KH 1–8 °dH. Adaptable across a broad range of conditions. Best colours in soft, slightly acidic water.

Feeding: Omnivore. Accepts quality flake, micro pellets, frozen bloodworm, brine shrimp, and Daphnia. Feed twice daily. Medium-sized mouths accept most standard community foods.

Tank Mates: Excellent with virtually all peaceful community species: other tetras (including Red Phantoms for a classic pairing), rasboras, corydoras, gouramis, loaches, and peaceful cichlids. Avoid aggressive or predatory species.

Behaviour: Peaceful schooling fish. Males may display to each other with fin-spreading and parallel swimming — this is dominance behaviour, rarely causing harm. Keep in groups of 8+ for best schooling behaviour. Mix of male and female provides the most natural social dynamic.

Health: Hardy and disease resistant. Avoid ammonia and nitrite spikes during cycling. Weekly 25% water changes maintain excellent health. Susceptible to ich during sudden temperature drops.