Congo Tetra

With iridescent scales that shift from blue to gold and from orange to purple depending on the angle of the light, the Congo tetra is one of the most eye-catching schooling fish in the hobby. The middle of the males' tail fin extends like a veil with white edges; the dorsal fin is long as well. Because it reaches 8–9 cm, it is larger than the classic tetras and needs a spacious aquarium.

It lives in slow-flowing river branches of the Congo Basin with murky, soft water. In the wild the light filters down through the forest canopy above.

• Volume: at least 150 liters and 100 cm of length for a school of 6–8; it is an active, large-bodied school.
• Water: 24–26°C, soft to moderately hard, slightly acidic to neutral. Regular water changes bring out the colors.
• Light: dim light and floating plants increase both color and confidence; a dark substrate is preferred.
• Lid: it may jump when startled.

Omnivorous. Quality flakes and granules, frozen brine shrimp, mysis and bloodworms; plant-based food from time to time. It may nibble soft-leaved plants.

Peaceful but skittish; it opens up in a crowded, safe environment. Males show off to each other but do not fight seriously.

Good companions: corydoras, Synodontis catfish, large rasboras, angelfish (in a large tank), calm gouramis.

Avoid: fin nippers (the males' long fins become a target), very small fish (adult Congos may eat fry and very small fish), aggressive cichlids.

At least 6, ideally 8 or more individuals; a female-heavy group (2 females per male) is the most balanced arrangement. Males show off by spreading their fins in front of each other; this is the Congo tetra's most beautiful behavior and is seen only in a large group.

It breeds in the aquarium as an egg scatterer: pairs spawn among the plants with the morning light, and the eggs fall to the bottom. Because the parents eat the eggs, a separate tank with mesh or marbles on the bottom is needed. The eggs hatch in about 6 days, which is a long time for tetras.

It is hardy, but it may react to sudden water changes and poor water with fin rot. The males' long fins are prone to injury.

Males are larger and more colorful; the middle of the tail fin extends like a veil, and the dorsal fin is long and pointed. Females are smaller, paler (gold-silver) and short-finned.