Prionobrama filigera · Glass Bloodfin Tetra

Overview

The slender, red-tailed Prionobrama filigera is an active fish of open upper water. Newly introduced groups can be nervous, so combine swimming space with conspecific company and patches of floating shelter.

Distribution & habitat

Records span the Amazon drainage in Ecuador, Colombia, Peru, Bolivia, and Brazil. Specific habitat data are lacking. Its shape and behavior suggest smaller streams and tributaries rather than major channels, but that remains an inference.

Aquarium setup

Leave generous open water for swimming. Peripheral planting and floating patches provide an attractive setting and help calm skittish fish. Fine wood branches and leaves on the bottom add a natural appearance.

It adapts to mildly acidic or mildly alkaline conditions within its suitable range, with stability preferable to unnecessary adjustment.

Diet & feeding

An upturned mouth and body form suggest surface invertebrates as important natural prey, without establishing a complete diet. Captive fish especially enjoy live or frozen water fleas, bloodworms, and Cyclops, while most accept dry food eagerly. Vary the ration for good color and condition.

Behaviour & compatibility

Generally peaceful, it may show occasional male rivalry. Keep at least six to eight together. Similarly sized characins, suitable cory or small suckermouth catfishes, and compatible cichlids are possible companions.

Avoid larger, rapid swimmers occupying the same upper zone. Strong competition for food and space can leave this species at a disadvantage.

Sexual dimorphism

Mature females become fuller in the abdomen, particularly when gravid. Healthy males have a dark anal-fin stripe alongside the white edge found in both sexes. Slight dorsal and anal extensions are also reported in males.

Breeding

Captive breeding is relatively straightforward. For higher fry survival, prepare a separate dim aquarium with fine vegetation or spawning mops, or use mesh that protects fallen eggs from the adults.

Soft, acidic water around pH 6.0–7.0 and GH 1–5 can be used, with temperature toward the upper end of the suitable range. Filtration is optional; a very gentle sponge filter adds oxygenation and may provide microbial grazing for fry.

Spawning can involve roughly six fish of each sex, or a selected pair. For pairs, condition the sexes separately, then move a full female and strongly colored male in the evening. Spawning commonly follows the next morning.

Remove adults as soon as eggs are seen. Hatching takes approximately 14–36 hours depending on temperature, followed by free swimming three to four days later. Microscopic starter foods precede microworms or brine-shrimp nauplii.

Notes

Compared with Aphyocharax anisitsi, this fish is more elongated and lacks red in the pelvic and anal fins. The relative Prionobrama paraguayensis lacks the red tail, making these features more useful than the broad bloodfin trade label.