Colombian Tetra

Geographic Origin and Biotope: Endemic to a small debris-filled stream (Rio Acandi) in the Gulf of Darién basin, Colombia. Its biotope is not the classic "Blackwater", but clear or slightly turbid slow-flowing streams.

Taxonomy and Morphology: Colombian Tetra (Hyphessobrycon columbianus). "Giant" tetra of the family, which can reach nearly 7 cm (2.8 inches). Has a tall shield-shaped body, laterally compressed, giving it an appearance very similar to a miniature piranha.

Social Behavior: Very active, bold, and gregarious. Intra-specific interactions are vigorous: males engage in bloodless fights displaying their fins for hierarchical dominance. Must be kept in groups of minimum 8-10, to dilute mutual aggression (fin-nipping).

Coloration and Sexual Dimorphism: Breathtaking livery: metallic silver body with strong cobalt-blue iridescence on the back, accompanied by ventral, anal, and caudal fins of a dense blood red. Females are noticeably stouter and less colorful; males have slightly more elongated dorsal fins.

Aquarium Setup: Needs large aquariums (minimum 100-120 cm / 40-48 inches long) as it is a powerful swimming fish. Setup with open central space, dense perimeter vegetation (e.g. Vallisneria, Java ferns) and a dark bottom.

Diet and Feeding: Extremely voracious omnivore. Dry food in granules/flakes is fine, but it appreciates meaty prey (bloodworms, mysis, brine shrimp) and bits of blanched zucchini. May occasionally nibble on soft-leaved plants if not fed enough.

Water Quality: Robust, adapts very well to classic dechlorinated tap water (pH 6.0-7.5, GH up to 15). Hates excessively cold waters. Sensitive to extreme nitrate fluctuations.

Compatibility and Tankmates: Ideal fish for a community of robust medium-sized fish (medium Plecostomus, Cichlids like Angelfish, Rainbowfish). Due to its bold character and size, not recommended with tiny rasboras or bettas, whose fins it would nip.

Aquarium Reproduction: Very prolific and easy to breed in planted tanks. They lay hundreds of eggs among the vegetation in the morning. Without the removal of parents and abundant feeding, they will prey on the fry.

Risks and Diseases: Very robust to common diseases. Only caution: dominant males superficially injured during skirmishes can develop mild bacteriosis if the water is highly polluted. Prevent with good filters.