Black Neon Tetra

The black neon tetra has a simple but striking pattern made up of a broad black band running along the body and a bright, greenish-white stripe just above it. The upper half of the eye is red. Although its name resembles the neon's, it belongs to a different genus and is hardier than the neon.

Almost all fish sold in the trade are farm-bred. Its adaptability to a wide range of water conditions, disease resistance and peaceful nature make it one of the best tetras for beginners.

It lives in the slow-flowing, vegetated and shaded tributaries of the Taquari River system, part of the Paraguay basin, in the Brazilian state of Mato Grosso do Sul. The water is soft and slightly acidic.

• Volume: at least 60 liters for a school of 8–12; a length of 60 cm or more.
• Water: 23–26°C, pH 6–7.5; it prefers soft water but also adapts to moderately hard water.
• Decor: A dark substrate and a densely planted background bring out the black-and-white pattern. Leave open swimming space in the middle.
• Maintenance: 20–25% water change weekly; gentle to moderate flow.

Omnivorous and easy to feed. Small granules and flakes should be the staple; vary the diet with frozen brine shrimp, daphnia, cyclops and small bloodworms. Feed 1–2 times a day, as much as is eaten within a few minutes.

A very peaceful and active species. It swims as a school in the middle and upper-middle layers of the tank. It has no tendency to nip fins and leaves adult shrimp alone.

Good companions: neons and other small tetras, rasboras, corydoras, otocinclus, dwarf gouramis, small livebearers, dwarf cichlids, shrimp.

Avoid: fish large enough to fit it in their mouths (including adult angelfish) and aggressive species that chase constantly.

At least 8, ideally 12 or more individuals are recommended. In a large school black neons turn together and behave more boldly; when kept in small numbers the school breaks up and their colors fade. The sex ratio does not matter.

It can be bred in the aquarium. Prepare a separate tank with soft, acidic water (around pH 6), dim light and fine-leaved plants or a spawning mop. The female scatters her eggs among the plants; the parents must be removed because they eat the eggs. The fry become free-swimming after a few days and are fed infusoria.

• Hardiness: resistant to disease; most problems come from poor water quality.
• White spot (ich): may appear in newly arrived fish and with sudden temperature changes.
• Quarantine: keeping new fish separate for 2 weeks protects the school.

Females are larger with a noticeably fuller belly. Males are slimmer. The difference is easiest to see from above or by comparing individuals side by side in a mature group.