Amazonian Red-eyed Tetra (Moenkhausia sanctaefilomenae)

Common Name:

Amazonian Red-eyed Tetra.

Scientific Name:

Moenkhausia sanctaefilomenae.

Other Names:

Red-eyed Tetra, Glass Tetra, Redeye Tetra.

Family:

Tetragonopteridae, but some place it in Charcidae within the subfamily Tetragonopterinae.

Distribution:

Paraguay and east Bolivia west to the Peruvian border with Brazil.

Size:

Approx 2.5 inches or 6cm.

Diet:

Aquatic insect larvae, but they'll take most commercially available aquarium foods. Live foods are always appreciated!

Water Temperature:

74 to 81 degrees Fahrenheit (22 to 26 degrees Celsius).

Water Chemistry:

They need soft water, but may be able to adjust to hard water through drip acclimation.

pH:

5.5 to 8.5 is all right for long term maintenance, but anything outside of 6-7 requires drip acclimation.

Life Span:

5 years, give or take two.

Description:

Unlike its congener, the Diamond Tetra (M. pittieri), this is a somewhat streamlined fish with less severe of a contour and smaller fins (though it is less laterally-compressed than its confamiliar, the torpedo-shaped Neon, Paracheirodon innesi). The caudal peduncle is black (as is the front half of the tailfin). The top half of the "iris" of its eye is eponymously red (while the bottom is the same silver as the rest of the body). Its scales are large and pronounced, and they are mostly a muted grey-silver, with some muted golden highlights throughout. It seems as though the front half of the body below the lateral line is more reflective than the rest of the body, but more pictorial evidence needs to be shown in order to confirm this observation.

Species Behaviour:

These can be very peaceful, but very active, and will bother slow-moving fish as well as those with long fins. They need to be kept in schools of at least eight (according to Mark Phillip Smith).

Sexing:

Females that are ready to spawn will be thicker than males in the same condition. They are otherwise isomorphic.

Breeding:

These fish will spawn in water where the light has been diffused, and the dH is between 0 and 4. They generally like to spawn on finer-leafed plants, and will place their eggs there. The parents are oophagous, so their removal immediately after egg laying is a good idea.

The fry can take either infusoria or pelletized egg layer fry foods at birth, and will quickly graduate to Artemia ssp. brine shrimp within a week. They can take finely-crushed flakes at two weeks of age.

Water Quality:

They need soft water, but might be able to adjust to hard water through drip acclimation. Smith recommends dH levels under 5. A pH 5.5 to 8.5 is all right for long term maintenance, but anything outside of 6-7 also requires drip acclimation.

Natural Conditions:

These live in slow-moving creeks and lakes with lots of vegetation.

Minimum recommended tank size:

15 gallons is the barest minimum, but I recommend nothing short of a 20 (Long).

Tank levels:

Top-Middle.

Feeding:

While they take aquatic insect larvae in the wild, these fish will take commercially available and prepared foods in aquaria. They appreciate the addition of live foods to their diets, and this may be a good part of a regimen in which they are prepared for breeding.

Miscellaneous:

These were once considered to be Tetragonopterus sanctaefilomenae or Moenkhausia sanctae-filomenae but those names went out of fashion many years ago, and neither appears in any relevant aquarium literature except as a footnote.