Red Eye Tetra

The Red Eye Tetra, scientifically known as Moenkhausia sanctaefilomenae, is a hardy and popular species of tetra native to the rivers and streams of South America, particularly in Brazil, Paraguay, and Argentina. It is highly valued in the aquarium hobby for its active schooling behavior, ease of care, and distinctive appearance.

Adult Red Eye Tetras typically reach about 2 to 2.5 inches (5 to 6.5 cm) in length. They have a sleek, silver body with a subtle green or gold sheen, a clear to slightly yellowish tail with a bold black band near the base, and their most distinctive feature—a vivid red spot on the upper part of each eye. This bright red “eyeshadow” is especially prominent in healthy, well-conditioned fish.

A tank of at least 20 gallons is recommended for a group. Red Eye Tetras are peaceful, active schooling fish that should be kept in groups of six or more to promote natural behavior and reduce stress. The aquarium should have a soft sand or fine gravel substrate, areas of open swimming space, and some live or artificial plants and driftwood for cover. Moderate lighting and a gentle current mimic their natural environment.

Water parameters should include a temperature range of 72 to 80°F (22 to 27°C), a pH between 6.0 and 7.5, and soft to moderately hard water. Red Eye Tetras are tolerant and hardy but thrive best in clean, well-maintained water with regular partial water changes.

Feeding Moenkhausia sanctaefilomenae is straightforward, as they are omnivorous and will accept high-quality flakes, pellets, and a variety of live or frozen foods such as bloodworms, brine shrimp, and daphnia. A varied diet will keep them healthy and bring out their best coloration.

Red Eye Tetras are peaceful and do well in community tanks with other similarly sized, non-aggressive species such as other tetras, rasboras, Corydoras, and peaceful cichlids. Avoid keeping them with large or aggressive tankmates.

Breeding the Red Eye Tetra in captivity is possible. They are egg scatterers and show no parental care. To breed, use a separate tank with fine-leaved plants or spawning mops and soft, acidic water. Remove adults after spawning to prevent them from eating the eggs. Fry can be raised on infusoria or powdered foods until they are large enough for baby brine shrimp.

Moenkhausia sanctaefilomenae (Red Eye Tetra) is a lively, robust schooling species that brings motion, subtle shimmer, and a distinctive splash of color to community and South American aquariums.