Redeye Tetra Care Guide - Aquarium Setup, Diet & Breeding

The Redeye Tetra is a lively, silver-bodied schooling fish named for the vivid red colour across its iris. Its body is usually translucent silver with a dark-edged, pale yellow to black marking near the base of the tail, while the fins can show subtle yellow, orange or reddish tones. In a well-lit aquarium, its reflective scales give the shoal a bright, constantly moving appearance.

This species is active, social and alert, spending much of its time in the middle levels of the water. A group moves together when startled but often spreads out to explore before regrouping. Redeye Tetras are generally peaceful, although cramped groups or unsuitable companions can encourage fin-nipping behaviour.

In the wild, they inhabit warm freshwater environments with areas of cover provided by submerged vegetation, branches and leaf litter. Their natural waters may vary from clear to tea-coloured, depending on the amount of tannin released by decaying leaves and woody material.

Moenkhausia sanctaefilomenae is a widely kept member of the characin family and is sometimes sold under the names Yellow-Banded Tetra or Lamp Eye Tetra. Its hardiness, striking eyes and energetic shoaling make it a popular choice for a peaceful community aquarium.

Redeye Tetras are native to central and eastern South America, particularly the river systems of Brazil, Bolivia and Paraguay. They occur in tributaries, floodplain waters and other slow-moving freshwater habitats associated with the Paraguay and Paraná basins, as well as nearby drainage systems.

A group of Redeye Tetras should have an aquarium of at least 75 litres, with a footprint around 90 cm long by 30 cm wide to provide room for sustained swimming. Use open central swimming space alongside dense planting around the rear and sides, with driftwood, roots or leaf litter creating shaded areas. A dark, fine-grained substrate helps their colours stand out, while gentle to moderate water movement and a secure cover are beneficial. Filtration should provide stable, well-oxygenated freshwater without creating an excessively turbulent current.

Up to 7 cm (2.8 in) in total length. Females are usually slightly larger and deeper-bodied than males, while males tend to remain slimmer.

Redeye Tetras are omnivores that accept quality small flakes, micro-pellets and granules. Their diet should be varied with frozen or live foods such as brine shrimp, daphnia, bloodworm and mosquito larvae, offered in appropriately sized portions. Regular vegetable-based ingredients are also useful, and small meals fed once or twice daily help match their active feeding behaviour.

Redeye Tetras suit peaceful community aquariums containing similarly sized, active fish. Suitable companions include other medium-sized tetras, peaceful rasboras, danios, Corydoras catfish, small to medium peaceful barbs, bristlenose catfish and non-aggressive dwarf cichlids. Avoid housing them with large predatory fish, highly aggressive species or very slow fish with long, delicate fins, which may be harassed or nipped. Keeping a proper group helps distribute their attention and usually reduces fin-nipping.

Redeye Tetras are egg-scattering characins that can be bred in a separate, dimly lit aquarium with soft, clean water and fine-leaved plants or spawning mops. Condition a group with plenty of small live or frozen foods, then introduce the adults when females are full of eggs. Spawning usually takes place among the plants, after which the adults should be removed because they may eat the eggs. The eggs generally hatch within 24 to 36 hours, and the tiny fry can initially be fed infusoria or commercially prepared fry food before progressing to newly hatched brine shrimp.

Females are generally fuller-bodied, particularly when carrying eggs, and may be slightly larger overall. Males are typically more slender, with a leaner profile; colour differences are subtle and not always reliable.