Red Eye Tetra

The Red Eye Tetra (Bario sanctaefilomenae, formerly Moenkhausia sanctaefilomenae) is a hardy, beginner-friendly freshwater fish renowned for its bright silver body, metallic shine, and a distinctive bright red circle over the upper half of its eye.

Overview & Care Chart

Native to the slow-moving river basins of South America (including Brazil, Paraguay, Peru, and Bolivia), this energetic mid-level swimmer is highly adaptable. Because they tolerate varying water parameters, they make an excellent choice for a community tank.

Adult Size: 2.75 to 3 inches (6–7 cm)

Lifespan: Approximately 5 years

Minimum Tank Size: 20 gallons (75 liters)

Water Temperature: 72°F to 82°F (22°C to 28°C)

pH Range: 5.5 to 8.5 (highly adaptable)

Diet: Omnivore (accepts flakes, pellets, and frozen foods)

Behavior & Tank Mates

Schooling Dynamics: Keep them in schools of 6 or more. Solitary fish can become stressed or prone to nipping fins.

Active Nature: Often nicknamed "silver bricks," they are active, brave swimmers that stay out in open spaces.

Ideal Tank Mates: Peaceful community fish including Corydoras catfish, loaches, hatchetfish, and medium-sized peaceful cichlids like Eartheaters. Avoid keeping them with slow-moving, long-finned fish or very small dwarf shrimp.

Tank Environment & SetupTo best showcase their metallic colors, provide a well-planted tank with plenty of open swimming room in the center. Adding driftwood and floating plants helps provide security.