Aquarium Knowledge

Rummy-Nose Tetra

Hyphessobrycon rhodostomus

A hardy, active South American tetra known for its silvery body, dark-edged fins and energetic schooling behaviour.

Rummy-Nose tetras (Hyphessobrycon rhodostomus) swimming in a planted freshwater aquarium
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Rummy-Nose tetra at a glance

Scientific nameHyphessobrycon rhodostomus
OrderCharaciformes
FamilyCharacidae
GenusHyphessobrycon
OriginSouth America — Brazil, Colombia and the Guiana Shield region, associated with Amazonian blackwater and clearwater habitats
Adult sizeAbout 4–5 cm (1.6–2 in)
Tank size (min)75 L / 20 gal for a school; a longer footprint is preferred
Temperature23–28 °C (73–82 °F)
pH range4.0–7.0
Water hardnessVery soft to soft
DietOmnivore — flakes, pellets, frozen and live foods
TemperamentPeaceful, energetic schooling fish
Care levelBeginner

Overview

The Rummy-Nose tetra (Hyphessobrycon rhodostomus) is a robust South American characin that has been popular in the aquarium hobby for decades. Its silvery body, darker dorsal and anal fins and warm red accents make it easy to recognise, while its energetic nature gives a community aquarium plenty of movement.

This is a more substantial tetra than many nano species. It is peaceful enough for a community aquarium, but its constant swimming and occasional fin-nipping mean it should be kept with appropriately sized, active tankmates. A proper school and a long aquarium are much more important than keeping it in a small decorative tank.

Rummy-Nose tetra size & lifespan

How big do Rummy-Nose tetras get?

Adults usually reach about 4–5 cm (1.6–2 inches). Females can look deeper-bodied than males, especially when mature and carrying eggs.

How long do Rummy-Nose tetras live?

In a clean, stable aquarium, Rummy-Nose tetras can live around 5–6 years, sometimes longer. A varied omnivore diet, good filtration, regular maintenance and sufficient swimming space are key factors in keeping them healthy over the long term.

Natural habitat & origin

Hyphessobrycon rhodostomus is native to the upper Amazon and Orinoco drainage systems of northern South America, especially the Amazonian and Orinoco-region waters of northern South America. Wild fish are associated with slow-moving, shaded blackwater environments where leaf litter, submerged roots and dense vegetation provide cover and feeding opportunities.

Aquarium specimens are widely captive-bred. A planted aquarium with open swimming space, moderate current, good oxygenation and stable water conditions provides a suitable captive environment without needing to duplicate every detail of the wild habitat.

Map showing the native range of the Rummy-Nose tetra in South America
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Rummy-Nose tetra tank size & requirements

A 20-gallon (75 L) long aquarium is a sensible minimum for a school of Cardinal tetras. The species is active and can reach a substantial size for a tetra, so horizontal swimming room is more useful than extra tank height. A secure lid is recommended because active tetras can jump when startled.

How many Rummy-Nose tetras in a 10 or 20 gallon tank?

A 10-gallon aquarium is generally too cramped for a proper long-term school. In a 20-gallon tank, a group of 8–10 is a better starting point when filtration and maintenance are strong. Larger aquariums are better for larger groups and mixed community stocking.

5 gal (19 L)Not recommended — too small for an active school of Rummy-Nose tetras.
10 gal (38 L)Not recommended as a long-term home; a school needs more swimming room and stable water quality than a small nano aquarium can reliably provide.
20 gal (75 L)A practical minimum for a school of 6–8, preferably in a longer aquarium.
29 gal (110 L)8–12 Rummy-Nose tetras, with room for compatible peaceful tankmates.
55 gal (208 L)A larger school of 12–20 can work well, with substantial swimming space and careful community stocking.

Water parameters

Temperature23–28 °C (73–82 °F)
pH4.0–7.0
Hardness (GH)Very soft to soft
Filtration turnoverModerate circulation with good oxygenation

Use a fine gravel or sand substrate, hardy live plants and an unobstructed swimming lane through the middle of the aquarium. Rummy-Nose tetras may nibble tender vegetation, so tougher plants are a safer choice than delicate soft-leaved species. Moderate filtration and good oxygenation suit their active nature.

Not sure how many litres your tank holds? Check it with theaquarium volume calculator.

Planted long aquarium setup suited to a school of Rummy-Nose tetras
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What do Rummy-Nose tetras eat? Diet & feeding

Rummy-Nose tetras are unfussy omnivores. A quality flake or appropriately sized pellet makes a good daily staple, while frozen or live foods such as daphnia, brine shrimp and bloodworms provide variety and useful enrichment.

Feed small portions once or twice daily and provide only enough food for the school to finish in a few minutes. Because these fish are active and persistent feeders, overfeeding is easy and can quickly contribute to poor water quality.

Rummy-Nose tetra tank mates & compatibility

Keep Rummy-Nose tetras in a school of at least six. They are peaceful by nature, but their energetic swimming style makes them a better match for robust, similarly active community fish than for timid nano species.

Are Rummy-Nose tetras aggressive? They are not usually aggressive, but individuals may chase one another or nip fins. This behaviour becomes more noticeable in cramped tanks or when they are kept in an undersized group. Spacious aquariums and compatible tankmates are the best prevention.

Good Rummy-Nose tetra tank mates

  • Other peaceful, similarly sized tetras and characins
  • Larger peaceful rasboras and active community schooling fish
  • Corydoras catfish suited to the same temperature range
  • Peaceful loaches and other bottom-dwelling community fish
  • Bristlenose plecos in appropriately sized mature aquariums
  • Peaceful medium-sized livebearers when water chemistry overlaps
  • Other robust community fish that can tolerate their active swimming

Avoid

  • Large predatory fish that can swallow adult Rummy-Nose tetras
  • Highly aggressive or territorial cichlids
  • Very slow, delicate or long-finned fish that may be stressed by their activity
  • Tiny shrimp and newly hatched fry, which may be eaten
Rummy-Nose tetras swimming with peaceful community aquarium fish
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How to breed Rummy-Nose tetras

Rummy-Nose tetras are egg-scattering fish and can spawn readily when adults are healthy and well conditioned. Feed a varied, nutritious diet for several days before moving selected adults to a separate breeding aquarium.

Use fine-leaved plants or a spawning mop to catch the eggs, provide gentle aeration and keep lighting subdued. Remove the adults after spawning because they may eat the eggs. Once the fry hatch, provide suitably tiny first foods and gradually transition them to newly hatched brine shrimp and other larger foods as they grow.

Male and female Rummy-Nose tetra comparison
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Naming & buyer’s notes

Rummy-Nose tetra is the standard aquarium name for Hyphessobrycon rhodostomus. This species is often confused in the trade with other fish sold as rummy-nose tetras, particularly Hemigrammus bleheri. When buying, choose active fish with clear eyes, intact fins, good body condition and strong interest in food. Avoid specimens that remain lethargic, have clamped fins or show obvious signs of disease.

Classic schooling tetra

Do not plan for this species like a tiny nano tetra. Its adult size and constant activity make a longer aquarium much more appropriate.

Plant selection

They are generally plant-safe. Dense planting and floating cover can provide useful shade and help the school feel secure.

Buy a group

A school is essential for normal social behaviour. Buying several healthy specimens together is preferable to keeping a single Rummy-Nose tetra as a display fish.

Rummy-Nose tetra FAQ

How big do Rummy-Nose tetras get?
Rummy-Nose tetras commonly reach around 4–5 cm (1.6–2 inches) as adults. Their compact size makes them a popular schooling fish for planted and planted and blackwater-style community aquariums.
How long do Rummy-Nose tetras live?
Rummy-Nose tetras commonly live around 5–6 years in a well-maintained aquarium, with some individuals living longer when water quality, nutrition and husbandry are consistently good. Good water quality, a varied diet, adequate swimming space and proper schooling conditions help them reach a healthy lifespan.
How many Rummy-Nose tetras should be kept together?
Keep at least six together, with a larger group often producing more natural, tightly coordinated schooling behaviour. They are active social fish and generally do best when they are not kept singly or as a pair.
What size tank do Rummy-Nose tetras need?
A 20-gallon (75 L) aquarium is a practical minimum for a proper school, but a longer aquarium is preferable because Rummy-Nose tetras are active schooling fish and benefit from a longer swimming footprint.
What do Rummy-Nose tetras eat?
They are omnivores and readily accept quality flakes and pellets. Supplement the staple diet with frozen or live foods such as daphnia, brine shrimp and bloodworms. Small portions once or twice daily are appropriate.
Are Rummy-Nose tetras aggressive?
They are generally peaceful, but they are energetic and can occasionally chase or nip. Their activity can be too much for slow, delicate or long-finned tankmates. A sufficiently large school and spacious aquarium usually help keep social behaviour manageable.
Do Rummy-Nose tetras eat plants?
They generally do not damage healthy aquarium plants. A planted tank with fine-leaved plants, floating cover and shaded areas can actually help Rummy-Nose tetras feel secure and display more natural schooling behaviour.
Can Rummy-Nose tetras live with other tetras?
Yes, provided the aquarium is large enough and the other species are peaceful and robust enough to tolerate their activity. Avoid pairing them with very small, timid species that may be overwhelmed by their constant movement.
How do you breed Rummy-Nose tetras?
Rummy-Nose tetras are egg-scatterers. Condition males and females with varied foods, then place them in a separate breeding aquarium with fine-leaved plants or a spawning mop. After spawning, remove the adults because they may eat the eggs. Raise the tiny fry on suitably sized first foods before moving to larger foods as they grow.