Congo Tetra

Geographic Origin and Biotope: Native to the massive Congo River in Central Africa. Swims in large schools in shaded marginal zones where acidic, tannin-stained blackwater softens sunlight and provides cover from predators.

Taxonomy and Morphology: As an African Alestidae, it is much larger than typical South American tetras, easily reaching 8-10 cm. Large scales reflect light like optical prisms. The eyes are unusually large for forest twilight.

Social Behavior: Despite its size, it is a gentle and extremely skittish giant. A sudden movement or light turning on causes a lethal explosion of panic, resulting in broken spines or smashed mouths against the glass. Must be kept in schools of 8-10+.

Coloration and Sexual Dimorphism: Breathtaking adult males boast rainbow scales (blue, red, gold) and ghostly, feather-like elongations of the caudal and dorsal fin rays. Females are smaller, olive-silver, with short fins.

Tank Setup: Demands wide open central swimming spaces (minimum 120 cm tanks) bordered by forests of Anubias or tall plants shading the surface. Dark substrate is mandatory to enhance iridescence; direct light terrifies the school and chronically fades their color.

Feeding and Diet: Formidable mid-to-surface micro-predators. Famous for their absolute preference for winged insects (Drosophila) and frozen foods. Protein is essential for developing the veil fins.

Water Quality: The species' true Achilles heel. *Absolutely zero* tolerance for ammonia or nitrites, and suffering above 20ppm nitrates. They require massive water changes and chemical peat filtration for vital humic acids.

Compatibility and Cohabitation: Ideal tankmates for Kribensis and Corydoras. Absolute ban on fin-nippers (e.g., Tiger Barbs, Serpae Tetras) which will strip the Congo Tetra's feathery fins overnight, killing them via traumatic shock.

Aquarium Reproduction: Males perform acrobatic displays, scattering eggs among fine-leaved plants at dawn. Parents are insatiable predators of their own spawn; without immediate removal, eggs vanish in minutes.

Risks and Diseases: Chronic "Fin Melting": in hard water (high GH/KH) or high nitrates, the tips of their fins fuse into a white fungal mass, leading to rapid necrosis and death. Formidable jumpers requiring heavy lids.