Overview of the Red Eye Tetra
The Red Eye Tetra (Moenkhausia sanctaefilomenae) is a popular freshwater fish known for its striking red eyes and silver body. Native to South America, this species has been a staple in the aquarium hobby for decades. Its active nature and schooling behavior make it a captivating addition to community tanks. In this guide, we cover all aspects of Red Eye Tetra care.
History and Origin
The Red Eye Tetra is native to the rivers of Brazil, Paraguay, and Bolivia, particularly the Paraná and Paraguay basins. It inhabits warm, slow-moving waters with dense vegetation. First described in 1911 by Eigenmann, it was introduced to the aquarium trade in the mid-20th century and has since become a favorite among hobbyists.
Physical Appearance
Size and Shape
Red Eye Tetras typically reach about 2.5-3 inches (6-7.5 cm) in length. They have a streamlined, laterally compressed body typical of tetras, with a shiny silver sheen.
Coloration and Markings
Their most iconic feature is the bright red ring around the eye, which gives them their name. The body is silvery with a faint black tail margin. The dorsal fin and other fins are clear or slightly yellow.
Sexual Dimorphism
Females are slightly larger and rounder, especially when gravid. Males have a more slender body and may be a bit more colorful.
Behavior and Temperament
Red Eye Tetras are active, peaceful, and social fish. They are schooling fish and should be kept in groups of at least 6-8 to feel secure. They dart around mid-water and occasionally nip fins of slow-moving fish if kept in small numbers. They are not aggressive but can be competitive during feeding.
Suitable Aquarium Conditions
Tank Size
Minimum 20 gallons (75 liters) for a school. A longer tank is better to provide swimming space.
Water Parameters
- Temperature: 72-79°F (22-26°C)
- pH: 6.0-7.5
- Hardness: 4-8 dH
Filtration and Water Flow
They prefer moderate water flow. A good filter with gentle circulation works best.
Substrate and Plants
Fine gravel or sand is suitable. Planted tanks with dense vegetation (e.g., Java fern, Amazon sword) provide hiding spots. Driftwood and dim lighting help mimic their natural habitat.
Diet and Feeding
Red Eye Tetras are omnivores. In the wild, they eat worms, insects, and plant matter. In captivity, a varied diet is essential:
- High-quality flake food
- Micro pellets
- Live or frozen foods: brine shrimp, daphnia, bloodworms
- Vegetable matter: blanched spinach or spirulina flakes
Feed 2-3 times daily in small portions they can consume within 2-3 minutes.
Health and Lifespan
Average lifespan is 3-5 years with proper care. Common health issues include ich (white spot disease), fin rot, and velvet disease. Quarantine new fish and maintain water quality to prevent illness.
Breeding
Breeding Red Eye Tetras in captivity is possible with a separate breeding tank. Condition breeders with live foods. The female scatters eggs among fine-leaved plants. Remove parents after spawning to prevent egg eating. Eggs hatch in 24-36 hours, and fry become free-swimming after 3-4 days. Feed infusoria or liquid fry food until they can eat baby brine shrimp.
Compatibility
Good tank mates include other peaceful community fish such as:
- Other tetras (neon, cardinal, black skirt)
- Rasboras
- Danios
- Small corydoras catfish
- Bristlenose plecos
Avoid slow-moving fish with long fins (e.g., angelfish, betta) as Red Eye Tetras may nip.
Grooming and Maintenance
Unlike mammals, fish do not require grooming, but tank maintenance is crucial:
- Weekly 20-30% water changes
- Clean filter monthly
- Test water parameters weekly
Cost Estimation
Initial setup (tank, filter, heater, lights, decorations): $150-$300. Monthly costs include:
- Fish food: $5-$10
- Water conditioners: $5-$10
- Electricity: $5-$15
- Miscellaneous (plants, replacements): $10-$20
Total monthly: approximately $25-$55.
Why Choose Red Eye Tetra?
They are hardy, affordable, and active, making them excellent for beginners. Their bright eyes add a unique sparkle to the aquarium. With proper care, they bring years of enjoyment.