Colombian Tetra

The Colombian tetra has a two-toned look, with a blue sheen covering the upper half of its silver body and bright red tail, anal and dorsal fins. For many years it was sold without a scientific name as the "blue-red Colombian tetra"; the species was described in 2002. It grows up to 6 cm and is sturdily built.

It is a hardy species that is easy to feed; its colors become very vivid as it matures. Because of its active nature, it gets along better with fish as active as itself than with calm, long-finned species.

It lives in the small Acandí River basin on the Caribbean coast of northwestern Colombia, near the border with Panama. Its natural range is quite narrow; the fish sold in the trade are mostly farm-bred.

• Volume: at least 100 liters for a group of 6–10; a length of 80 cm or more.
• Water: 23–26°C, pH 6–7.5, soft to moderately hard water.
• Decor: planted edges and a large open swimming area. Because it is an active species, choose a long tank.
• Maintenance: a 25% water change every week; moderate flow is tolerated.

Omnivorous with a big appetite. Make flakes and granules the staple and vary it with frozen brine shrimp, bloodworms and daphnia. It also accepts spirulina foods. Feed 1–2 meals a day, only as much as is eaten within a few minutes.

Active and curious. Chasing within its own group is common; when kept in small numbers or together with calm species, fin nipping becomes a problem. It hunts shrimplets; keeping it with small shrimp species is not recommended.

Good companions: active tetras of similar size, barbs, danios, corydoras, plecos, medium-sized peaceful cichlids.

Avoid: bettas, angelfish, fancy guppies and other long-finned fish; very small and slow species.

A group of at least 6, ideally 10 is recommended. In a large group the aggression is spread out within the school and the fish behave more naturally. The sex ratio does not matter. Groups of three or four are both shy and more ill-tempered toward their tankmates; the school needs to be set up with enough fish from the start.

It is an egg scatterer and can be bred in the aquarium. A separate tank is prepared with fine-leaved plants or a spawning mop and soft, slightly acidic water. The parents should be removed after spawning. The fry are raised on infusoria and newly hatched brine shrimp.

• Hardiness: it is generally a sturdy species.
• White spot (ich): may appear after transport; quarantine is recommended.
• Injury: fin wounds may occur from chasing within the school; clean water speeds healing.

Males are slimmer and more brightly colored; the red in their fins is more intense. Females are plumper and paler.