Rummynose tetra

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: any.

Behavior

Plant interaction: plant safe.

Feeding

Flake, micro pellets, frozen daphnia, bloodworm, and brine shrimp. Not fussy about food type. Feed small amounts 2-3 times daily. Rummynose tetras are midwater feeders and catch food as it drifts through the water column. Color improves with high-quality food containing carotenoids.

Compatibility

• One of the best community schooling fish. Peaceful, non-nippy, and stays in a tight group.
• Classic tankmate for angelfish, discus, rams, and other South American community fish. The tight schooling behavior is visually spectacular with these centerpiece fish.
• Works with corys, plecos, small gouramis, and other tetras.
• Avoid very aggressive tankmates. Rummynose tetras are not easily stressed but they lose their red coloration when harassed, which defeats the purpose of keeping them.
• Safe with shrimp and snails.

Origin and habitat

Three species are sold under the "rummynose tetra" label. All three were reclassified into the genus Petitella in 2020 after a molecular phylogenetic study, though older literature uses Hemigrammus for two of them. Petitella bleheri (firehead tetra, brilliant rummynose) is the most common in the trade and has the most extensive red coloration, extending beyond the gill cover onto the body; native to the upper Rio Negro and Rio Vaupés. Petitella rhodostoma (rummynose tetra, Ahl's rummynose) is native to the lower Amazon basin, type locality the Rio Tapajós near Santarém. Petitella georgiae (false rummynose) inhabits whitewater tributaries in the western Amazon, particularly in Peru. All three are now placed in the family Acestrorhamphidae, subfamily Megalamphodinae. In the wild, they inhabit forest creeks and floodplain backwaters with soft, acidic blackwater conditions, leaf litter, and subdued light. The brilliant red nose is a reliable water quality indicator: it fades to pale pink when the fish is stressed or water conditions deteriorate. They form tight, highly coordinated schools and are widely considered among the best schooling tetras for planted aquascapes; groups of 10 or more are recommended. P. bleheri reaches about 5 cm; P. rhodostoma and P. georgiae grow somewhat larger, to about 8 cm. Aquarium forms of P. bleheri include platinum, albino, and golden xanthic strains.

Breeding

Egg scatterer. Difficult to breed compared to most tetras. Requires very soft acidic water (pH below 6.0, GH below 3) and dim lighting. Condition breeding pairs with frozen food for two weeks. Spawning usually occurs at dawn. Eggs are scattered among fine-leaved plants and are light-sensitive. Remove adults immediately after spawning. Fry hatch in 24-36 hours and need infusoria for the first few days. The difficulty and specific water requirements mean most rummynose tetras in the trade are wild-caught from Brazil.

Common problems

The red nose fading is the most asked-about issue. It's a reliable stress indicator: pale nose = something wrong. Check ammonia, nitrite, temperature, and look for signs of harassment from tankmates. In a healthy established tank, the red should be vivid and extend well past the eye. Newly purchased rummynose almost always have a pale nose from transport stress; the color returns within a few days if conditions are good. Ich is common in new arrivals. Rummynose tetras need warm water (25–28°C) and stable conditions; they don't tolerate temperature swings well.

Bioload

Further reading

• Stocking ideas by tank size