Discus tetra - Brachychalcinus orbicularis

Scientific name: Brachychalcinus orbicularis

Common name: Discus tetra

Family: Characidae

Usual size in fish tanks: 8 - 9 cm (3.15 - 3.54 inch)

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Recommended pH range: 5.5 - 7.5

Recommended water hardness: 6 - 20°N (107.14 - 357.14ppm)

0°C 32°F30°C 86°F

Recommended temperature range: 20 - 26 °C (68 - 78.8°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Middle levels

General Information

Discus tetra (Brachychalcinus orbicularis) is a deep-bodied characin from lowland rivers and creeks in northern South America. Adults reach about 8–9 cm and display a rounded, laterally compressed “discus” profile with a dark humeral spot and subtle banding. It is a peaceful schooling fish that shows best color and behavior in groups of 6–8 kept in a long tank with open swimming space and cover around the margins.

Food & Feeding

An omnivore/micro-predator in nature, feeding on small invertebrates and plant material. Offer a varied staple of quality flakes or small sinking granules, plus regular portions of frozen/live foods (daphnia, mosquito larvae, brine shrimp, finely chopped bloodworms). Include some vegetable content (spirulina-based foods, blanched spinach/peas) a few times per week. Feed modest portions 1–2× daily to maintain water quality.

Sexing

External sexual dimorphism is subtle. Mature females tend to be a little deeper-bodied/plumper, especially when gravid; males often remain slightly slimmer. Accurate sexing typically requires comparison within a group.

Breeding

B. orbicularis is an egg-scatterer. Use a separate, dimly lit breeding tank with fine-leaved plants or spawning mops to catch adhesive eggs. Condition a small group on rich live/frozen foods. After spawning, remove adults as no parental care is provided. Depending on temperature, eggs typically hatch in ~2–3 days, and fry become free-swimming a few days later. Start with infusoria/liquid fry food, then transition to newly hatched brine shrimp. Reported fecundity for mature females can reach roughly 1,000–2,000 eggs per spawn.

Lifespan

Commonly 5–6 years with good diet and consistent maintenance.

Tank Requirements & Water Parameters

Tank size: a long footprint of 90–100 cm (36–40″) or larger for a group; prioritize open midwater lanes with cover around the sides/back.
Water: pH ~5.5–7.5; hardness approximately 6–20 °dH; temperature 20–26 °C (68–79 °F). Note: some references list 18–24 °C as typical; slightly warmer water is often used for conditioning and breeding.
Filtration & flow: clean, well-oxygenated water with regular, sizable water changes. Avoid chronic nitrate accumulation.
Aquascape: open center for schooling; robust plants, roots and wood at the margins. May nip very soft/fine-leaved plants; choose sturdier species if you keep a planted layout.

Compatibility & Tank Mates

Peaceful community fish. Keep in a shoal and combine with similarly sized, non-nippy neighbors (medium tetras/rasboras, peaceful cichlids of appropriate size, Corydoras and other calm catfishes). Avoid very small fish that could be outcompeted at feeding time, and notorious fin-nippers.

Behaviour & Usual Place in the Tank

Active mid-water shoaler that appreciates open space for schooling and darker, structured edges to retreat when startled.

Short Description

Discus tetra is a rounded, schooling characin suited to spacious, clean community aquaria. Provide a varied omnivorous diet, stable soft-to-moderately hard water, and a group to see calm behavior and attractive schooling.

Q&A

Where does it come from? Most sources place it in coastal drainages of Suriname and Guyana; some recent records extend into parts of the Amazon–Orinoco system.
How many should I keep? At least 6–8; larger groups look better and reduce skittishness.
Will it ruin my plants? It may nibble very soft plants; use sturdier species if you want a heavily planted aquascape.
How hard is breeding? Moderate: egg-scatterer with no parental care; needs a separate tank, dim light, and very clean water. Fry require very small first foods.