Rummy Nose Tetra

The Rummy Nose Tetra is one of the most iconic and sought-after schooling fish in the aquarium hobby. Native to the Rio Negro, Rio Vaupes, and other blackwater tributaries of the Amazon basin in Brazil and Colombia, the three commonly traded species (Hemigrammus rhodostomus, H. bleheri, and Petitella georgiae) all share the same distinctive appearance: a brilliant red head, silver body, and bold black-and-white horizontal stripes on the caudal fin.

In schools of 15 or more, Rummy Nose Tetras engage in extraordinarily tight, synchronized schooling behavior that creates a mesmerizing visual effect, particularly in large planted aquariums. The intensity of their red coloration also serves as a reliable health indicator — bright red indicates a healthy, unstressed fish, while pale color signals poor water quality or disease.

Native to acidic blackwater environments, Rummy Nose Tetras perform best in soft, acidic water with tannins. They are more sensitive to water quality than many other tetras and require stable parameters and excellent filtration. Regular water changes and the use of botanicals (Indian almond leaves, driftwood) that release tannins are beneficial.

They are completely peaceful omnivores that accept a wide range of small prepared and live foods. Their stunning appearance and schooling behavior make them a centerpiece species for planted South American biotope aquariums.

Water Parameters: Rummy Nose Tetras require soft, acidic water: pH 5.5–6.8, temperature 24–28°C, GH 1–8. They are sensitive to pH swings and high nitrates. Tannin-stained water from driftwood, Indian almond leaves, or peat filtration is strongly beneficial and intensifies their red coloration.

Tank Setup: Minimum 100 liters for a school of 15. A planted aquarium with dark substrate, driftwood, and subdued or dappled lighting from floating plants creates an ideal biotope. Open swimming space in the center with dense planting along borders encourages natural schooling. Gentle to moderate filtration.

Feeding: Small omnivores accepting micro flake food, micro pellets, small frozen bloodworm, daphnia, and brine shrimp nauplii. Feed twice daily in small amounts. Varied diet enhances their red coloration and overall health.

Tankmates: Ideal companions for other soft-water South American species: Cardinals, Green Neons, pencilfish, Apistogramma, Corydoras, and hatchetfish. Avoid hard-water species, aggressive fish, or large fish that will eat them.

Health: More sensitive than most tetras. Maintain excellent water quality — high nitrates cause rapid coloring. Perform 25–30% water changes weekly. Watch for neon tetra disease, ich, and velvet. The red nose intensity is a live water quality gauge: faded = problem.