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Diancema Tetra

Hyphessobrycon

A characin with robust and elevated shapes originating from Bolivia, adorned with a faint blackish longitudinal band and light reddish shades on the odd fins.

Taxonomy
Class:Actinopteri
Order:Characiformes
Family:Characidae
Genus:Hyphessobrycon
Species:Hyphessobrycon
Formerly known as:Hyphessobrycon diancema

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Water Temperature

22 - 28 °C

pH Value

5.5 - 7

Water type

Freshwater

Tank level

Middle

Adult size

4.5 cm

Minimum tank volume

>= 80 L

Minimum group

>= 6

GH

1 - 12 dGH

KH

2 - 8 dKH

TDS

35 - 260 ppm

Conductivity

55 - 406 uS/cm

Species description

Geographical Origin and Habitat: Widely distributed in the Amazon River basin (Brazil). Mostly inhabits slow-flowing rivers, channels, oxbows, and marginal areas of the flooded forest where the waters are clear but loaded with tannins.
Taxonomy and Morphology: Hyphessobrycon diancema. An ovoid, compact, and robust characin. The overall appearance is understated, often mistaken for similar species of the same genus if not under perfect lighting conditions.
Social Behavior: Eminently peaceful and gregarious. Like all tetras, it needs the security of the group (minimum 8 specimens) to overcome its shyness and move boldly in the water column. Males engage in mild skirmishes.
Coloration and Sexual Dimorphism: Semi-transparent to olive-gray body, crossed by a delicate iridescent golden/silvery reflection. A small drop-shaped dark spot adorns the caudal peduncle. Females are noticeably rounder at the abdomen.

Care, breeding and tankmates

Aquarium Setup: An 80 cm (32 inches) hobbyist aquarium is ideal. Set up with a dark background, a generous rear band of stem plants, and some bogwood roots, leaving a large central area free for swimming.
Diet and Feeding: Undemanding (Omnivore/Micro-predator). Good quality flakes and micro-pellets form the staple diet, but it is vital to provide mosquito larvae, daphnia, and brine shrimp to stimulate activity and reproduction.
Water Quality: Very adaptable and hardy, ideal for the average aquarist. Thrives in soft to moderately hard waters (GH 1-12) and acidic to neutral pH (5.5-7.0), with stable temperatures.
Compatibility and Cohabitation: Splendid "dither fish" for the South American community. Reassures shy bottom species (Apistogramma, Corydoras) with its lively swimming. Avoid pairing it with predatory fish like large cichlids or piranhas.
Aquarium Breeding: Lacking parental care, they scatter eggs randomly among mosses or roots at dawn. For the survival of the offspring, it is necessary to use a bottom net and separate the adults immediately.
Risks and Diseases: Extremely robust, almost "bulletproof". The only real risk is jumping out of the tank if frightened (a lid is essential) or very heavy water pollution.

Geographic Origin and Distribution

Widely distributed in the Amazon River basin (Brazil). Mostly inhabits slow-flowing rivers, channels, oxbows, and marginal areas of the flooded forest where the waters are clear but loaded with tannins.

Origin

Tropical oceans and reefsAmazon, Orinoco, and Guianas

Fish profile

Temperament
Semi-aggressive
This is a highly peaceful and somewhat shy species that thrives in a calm environment. They are a schooling fish that relies on the presence of conspecifics to feel safe and exhibit their best behavior. When kept in sufficiently large groups, they are active and inquisitive without ever bothering tank mates.
Diet
Omnivore
This species is an opportunistic omnivore that will easily accept a wide variety of aquarium foods. A staple diet of high-quality flakes or pellets should be provided daily. For optimal health and coloration, supplement with frozen or live foods such as bloodworms and brine shrimp.
Sex ratio
School
Maintaining a proper sex ratio is less critical for this species compared to some others, as they are a schooling fish. Keeping them in groups of at least eight to ten individuals ensures natural behavior and reduces stress. Having a mix of males and females can help diffuse any minor squabbles among displaying males.
Feeding frequency
Twice daily
These active fish benefit from multiple small feedings throughout the day rather than one large meal. Feeding them two to three times daily with amounts they can consume in under two minutes is ideal. This schedule helps prevent bloating and keeps water parameters stable by reducing uneaten food.
Bioload
As a moderately sized fish, this species produces an average bioload in the aquarium. Proper filtration is necessary to process the waste it generates efficiently. Routine maintenance and regular water changes will ensure a healthy environment.
Flow
Stagnant
Originating from slow-moving tributaries and forested pools, they prefer gentle to moderate water currents. High flow environments can quickly exhaust these fish and cause them significant stress. A sponge filter or a baffled hang-on-back filter provides the perfect amount of water movement.
Reproduction
Oviparous
They are egg scatterers that do not provide any parental care to their offspring after spawning. To encourage breeding, a separate tank with soft, slightly acidic water and fine-leaved plants is required. Once eggs are laid and fertilized, the adult fish must be removed promptly to prevent them from eating the eggs.
Compatibility & tankmates
This species is exceptionally peaceful and does well in community tanks with other small, non-aggressive fish. They should never be kept with large or boisterous species that might view them as food. Ideal tank mates include small rasboras, Corydoras catfish, and peaceful dwarf cichlids.
Tank level
Middle
This species primarily occupies the middle region of the aquarium water column during normal activities. They are active swimmers that appreciate ample open swimming space in the center of the tank. They will frequently dart in and out of plant thickets or hardscape for cover when resting.

Image gallery

Licensed images linked to the species or, when marked, to the closest representative taxon.

Related species

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Variants and close relatives

Same atlas type, nearby scientific identity, genus, or family.

Flag Tetra

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Hyphessobrycon heterorhabdus

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Meta Tetra

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Hyphessobrycon metae

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Copeland's Tetra

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Mutabilis Tetra

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Franke's Tetra

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Vilma's Tetra

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Hyphessobrycon vilmae

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Reticulated Tetra

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Hyphessobrycon reticulatus

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Agulha Tetra

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Hyphessobrycon agulha

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Blueberry Tetra

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Hyphessobrycon wadai

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Flame tetra

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Serpae Tetra (Red Minor Tetra)

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Hyphessobrycon eques

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Epicharis Tetra

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Dawn Tetra

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Loreto Tetra

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Hyphessobrycon loretoensis

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Coffee-bean Tetra

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Similar care

Cards with similar requirements, difficulty, habitat, and husbandry profile.

Socolof's Tetra

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Hyphessobrycon socolofi

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Hyphessobrycon megalopterus

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Balbus Tetra

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Flameback bleeding heart tetra

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Red Sailfin Tetra

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Pretty tetra

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Last updated: 06/30/2026