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Maximum size : 7 cm

Red Eye Tetra - Moenkhausia sanctaefilomenae : Complete Fish Profile & Care Guide

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The Red Eye Tetra (Moenkhausia sanctaefilomenae) is a great addition to any community aquarium. These peaceful and active fish are perfect for beginner aquarists who want to add elegance to their tank. Red Eye Tetras are tough enough to hold their ground and big enough not to become prey to other species. In their natural habitat, Red Eye Tetras are schooling fish, so keeping them in groups of at least six individuals is essential. Doing so will create a natural display and prevent aggression towards other fish species. You can add similarly sized Tetras, larger Rasboras, Rainbowfish, Barbs, and most Danios, as well as bottom dwellers such as Corydoras Catfish and Botia Loaches, to make ideal tankmates. Red Eye Tetras will thrive in most well-maintained tanks, but they prefer a less bright lighting and a moderately decorated environment. You can create a stunning aquascape by mimicking an Amazonian biotope setup with a sandy substrate, driftwood branches, and twisted roots. Adding dried leaves such as beech or oak will create a natural feel. Red Eye Tetras have a bright silver body with black coloring on the base of their caudal fin edged with white. Additionally, they have a thin bright red circle around their eye, making them an attractive species to add to your aquarium.

Red Eye Tetra Photos

Sexual Dimorphism

Distinguishing between a male and female Red Eye Tetra may pose some difficulty. Nonetheless, a few physical differences can aid in sex identification. Females, particularly those carrying eggs, tend to be slightly larger than males and display a more rotund abdominal region.

Quick Facts

Scientific NameMoenkhausia sanctaefilomenae
Year Described1907
Other Nameslamp eye tetra.
OriginsUruguay Paraguay Brazil Argentina
Max Size7 cm
Aquarium LevelMiddle - Top
Best kept asGroups 5+
Lifespan3 - 5 years

Water Parameters

Water TypeFreshwater
PH5.5 - 8.5
GH5 - 20
KH4 - 8
TDS100 - 200
75 - 85
23.9 - 29.4

Natural Habitat

Red Eye Tetras are native to Brazil, Paraguay, and Argentina, located in South America. Red Eye Tetras are commonly found in the Sao Francisco, upper Paraná, Paraguay, and Uruguay River Basins, located in eastern and central South America. They typically inhabit moderately flowing, clear waters of big rivers but can also be found in the thick vegetation of the murky Amazon. Adding Red Eye Tetras to your aquarium is an excellent way to showcase their unique beauty and contribute to their conservation efforts. So why wait? Explore the wonders of Red Eye Tetras and bring a touch of South America into your home today!\r\n
 São Francisco River - Brazil
Brazil Flag


Red Eye Tetras are egg-scattering free spawners and do not provide parental care. However, if you aim to produce a higher yield of fry, it is recommended to prepare a separate breeding tank with established water, dim lighting, and plenty of plants or spawning mops. You should also condition the breeding pairs with live, frozen, or freeze-dried foods, such as bloodworms or mosquito larvae, to encourage reproduction. During spawning, the females become more active, and males bump into them. The fish will then lock fins and carry out a somersault movement in the plants, where the female will scatter her eggs, and the male will fertilise them. Females can lay several hundred eggs during a single spawning. It is advisable to remove the adults from the breeding tank after the females have stopped scattering their eggs and the males have fertilized them. You should keep the tank dark, as Tetra eggs and fry are especially susceptible to light. The eggs will hatch in 24 to 48 hours, depending on the temperature, and the fry will become free-swimming three to four days later. You can feed the newly hatched fry on their yolk sac, and once they become free-swimming, you can provide them with rotifers or infusoria, moving on to baby brine shrimp and crushed flakes as they grow.

Diet & feeding

Red Eye Tetras have a versatile diet and will consume most types of food. However, to maintain their optimal health and vibrancy, it is recommended to feed them with frequent meals of small live, frozen, and freeze-dried foods, such as daphnia, bloodworm, and brine shrimp. High-quality dried food, including flakes and granules, should also be included in their diet, and adding vegetables like blanched courgette or spinach leaves can provide them with additional nutrients.

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