Buenos Aires Tetra Care Guide - Aquarium Setup, Diet & Breeding

The Buenos Aires Tetra is a lively, robust characin with a silvery body, dark-edged scales and a distinctive red-orange wash through the fins, especially the dorsal, anal and caudal fins. A dark marking near the upper part of the eye and a subtle dark shoulder spot add contrast to its otherwise bright appearance.

These tetras are active swimmers that spend much of their time in the middle and upper levels of the aquarium. They are social fish with confident personalities, and a well-established group constantly explores its surroundings rather than remaining hidden.

In the wild, Hyphessobrycon anisitsi is associated with South American freshwater habitats containing marginal vegetation, submerged plants and areas of open water. Seasonal changes in flow and water conditions occur across its broad native range, contributing to the species' adaptability.

Buenos Aires Tetras are among the larger and hardier commonly kept tetras. Their energetic nature and attractive red-finned colouration have made them popular in community aquariums, although their occasional tendency to nip fins should be considered when choosing companions.

Buenos Aires Tetras are native to the Paraná, Paraguay and Uruguay river systems of South America, with populations recorded in Argentina, Paraguay, Brazil and Uruguay. They inhabit warm, slow-moving and moderately flowing freshwater environments, including tributaries, ponds and vegetated margins.

A group of Buenos Aires Tetras should be kept in an aquarium of at least 75 litres, with a recommended footprint of approximately 90 cm long by 30 cm wide to provide uninterrupted swimming space. Use a secure lid because these active fish may jump, and combine open areas for swimming with hardy plants, wood or rocks around the edges. A dark sand or fine gravel substrate helps their colours stand out, while moderate water movement, efficient filtration and clear, well-oxygenated water support their active lifestyle.

Up to 7 cm (2.8 inches) in total length. Females are usually slightly larger and deeper-bodied than males, while males generally remain slimmer and may reach around 5–6 cm (2.0–2.4 inches).

Buenos Aires Tetras are omnivores and should receive a varied diet of quality flakes or small pellets alongside frozen or live foods such as bloodworm, brine shrimp, daphnia and mosquito larvae. They also graze on small amounts of algae and plant matter, so occasional spirulina-based foods or blanched vegetables can add useful variety. Feed only what the group consumes promptly, with appropriately sized portions offered once or twice daily.

Buenos Aires Tetras suit active community aquariums with similarly sized, robust fish such as larger rasboras, danios, peaceful barbs, rainbowfish, larger corydoras, peaceful loaches and appropriately sized peaceful catfish. They may nip the fins of bettas, gouramis, angelfish, fancy guppies and other slow-moving or long-finned fish, particularly when kept in too small a group. Avoid combining them with very small, timid species or aggressive predators.

Buenos Aires Tetras are egg scatterers and can be bred in a separate, mature breeding aquarium with soft to moderately hard water and fine-leaved plants or spawning mops. Condition the adults with plentiful live or frozen foods, then introduce several males and females. Spawning usually occurs among the vegetation, after which the adults should be removed because they may eat the eggs. The eggs hatch in roughly 24 to 36 hours, and the free-swimming fry can initially be fed infusoria or commercially prepared liquid fry food before progressing to newly hatched brine shrimp.

Females are typically larger, fuller-bodied and noticeably rounder through the belly, especially when carrying eggs. Males are generally slimmer and may show more intense fin colouration, although the difference is not always pronounced in young fish.