Hemigrammus pulcher (Carbuncle Tetra)

17 June 2026

396

Hailing from the slow-moving, tannin-stained waters of the Amazon basin, the Carbuncle Tetra (Hemigrammus pulcher) is a peaceful and captivating schooling fish. Also known as the Garnet Tetra, its striking reddish-gold spot and deep-bodied profile make it a highly sought-after, easy-to-keep addition to any lush planted community aquarium.

Overview

The Carbuncle Tetra, widely known in the aquarium hobby as the Garnet Tetra or Pretty Tetra (Hemigrammus pulcher), is a robust and visually charming freshwater fish. Known for its distinct markings and peaceful nature, it has been a staple in community aquariums for decades. Its hardiness and schooling behavior make it an excellent choice for both novice and experienced aquarists looking to add dynamic movement to their tanks.

Image of carbuncle tetra hemigrammus pulcher

Distribution and Habitat

This species originates from the upper Amazon River basin, specifically found in Peru, Colombia, and parts of Brazil. They primarily inhabit slow-moving tributaries, forest streams, and oxbow lakes. These environments are often heavily shaded by dense jungle canopy and feature blackwater conditions—water tinted dark brown by decaying leaf litter and submerged wood, which releases tannins and keeps the water soft and acidic.

Description of Carbuncle Tetra

Body shape:

Compared to many other tetras, the Carbuncle Tetra is relatively deep-bodied and laterally compressed, giving it a somewhat stocky appearance as it matures.

Color:

The body exhibits a silvery-grey base with subtle iridescent greenish or purplish reflections. Its most distinguishing feature is a broad, dark black wedge or teardrop shape located at the caudal peduncle (base of the tail). Immediately above this black mark lies a striking, glowing reddish-gold spot—the "carbuncle" or "garnet" that gives the fish its common names.

Barbels:

Like all characins, they do not possess barbels.

Snout:

They have a relatively short snout with a small, terminal mouth designed for picking tiny invertebrates from the water column.

Eyes:

The eyes are large in proportion to the head, featuring a brilliant red or intense orange upper iris that contrasts beautifully with their silver bodies.

Fins:

The fins are predominantly clear or transparent, though the dorsal and anal fins may occasionally show faint hints of yellow or red depending on the fish's diet and maturity.

The Tail:

The caudal fin (tail) is deeply forked and completely transparent, ensuring that the black wedge at the peduncle stands out prominently.

Temper

This species is highly peaceful and completely non-aggressive. They will not bother other tank mates and are generally quite timid if not kept in appropriate numbers or if housed with boisterous species.

Sociality

The Carbuncle Tetra is a true schooling fish. They must be kept in groups of at least 6 to 8 individuals, though larger groups of 10 or more are highly recommended. A proper school makes them feel secure, encourages their best coloration, and displays their natural synchronized swimming behaviors.

Activity

They are active mid-level swimmers. While they spend much of their time elegantly hovering or darting through the middle strata of the aquarium, they will readily venture to the surface during feeding time.

Keeping and Caring for Carbuncle Tetra

Tank size:

A minimum tank size of 60 liters (15 gallons) is recommended for a small school, though a 20-gallon long tank is ideal to provide them with ample horizontal swimming space.

Water Parameters:

Temperature

They thrive in tropical temperatures ranging from 23-27°C (73-81°F).

pH

To mimic their natural blackwater habitat, the pH should be kept slightly acidic to neutral, ideally between 5.5 and 7.0.

Hardness

Soft water is preferred, with a general hardness (dGH) ranging from 2 to 12.

Ammonia, Nitrite, Nitrate

Ammonia and Nitrite must always be at 0 ppm. Nitrates should be kept as low as possible, ideally below 20 ppm, through regular water changes and plant filtration.

Lighting

Dim to moderate lighting is best. Bright lights can wash out their colors and make them skittish. Floating plants are an excellent way to diffuse strong aquarium lights.

Water flow

They prefer gentle to moderate water flow, simulating the sluggish streams of their native habitat.

Decorations and Plants

A heavily planted aquarium with a dark substrate will make their colors pop. Driftwood branches, tangled roots, and dried botanicals (like Indian almond leaves) will recreate their natural environment and release beneficial tannins.

Diet

Carbuncle Tetras are omnivorous micro-predators. In the wild, they feed on tiny worms, crustaceans, and plant matter. In captivity, they will eagerly accept high-quality dry foods like micro-pellets and crushed flakes. To ensure optimal health and coloration, supplement their diet with live or frozen foods such as daphnia, brine shrimp, and bloodworms.

Some Feeding Tips

Feed them small portions once or twice a day—only what they can consume within two minutes. Because they have small mouths, ensure that the food particles are appropriately sized.

Breeding

Breeding the Carbuncle Tetra can be moderately challenging. They are egg scatterers and exhibit no parental care. To breed them, set up a separate dimly lit breeding tank with very soft, acidic water and fine-leaved plants (like Java Moss) or a spawning mop. Condition the adults with live foods. After spawning occurs, usually in the early morning, the parents must be removed immediately, or they will eat the eggs. The fry hatch in about 24-36 hours and become free-swimming a few days later, requiring infusoria or specialized liquid fry food until they are large enough to eat baby brine shrimp.

Conclusion

The Carbuncle Tetra is a delightful, undemanding species that brings subtle elegance and a splash of unique color to the freshwater aquarium. Their peaceful disposition, schooling nature, and adaptability make them a highly rewarding choice for any aquarist aiming to create a beautiful, harmonious South American biotope or a diverse community tank.

Fish info

Care level: Easy
Temperament: Peaceful
Adult size: 4.5 cm
Life expectancy: 3-5 years
Fish type: Tetra
Temperature : 23-27°C
pH: 5.5-7.0
Color Form: Black, Clear, Red, Silver

Related on Fishs

Leave your comments

Latest on Fishs

Dwarf Gourami Red (Trichogaster lalius)

Easy - Moderate

Asian labyrinth fish

The red dwarf gourami is a selectively bred color form of the dwarf gourami, a small labyrinth fish formerly widely known as Colisa lalia. It is suited to mature, planted community aquariums with gentle water movement and calm tank mates. Males can be territorial, especially when kept with females in confined conditions, so cover, visual barriers, and careful observation are important for a pair.
Cockatoo Cichlid Red (Apistogramma cacatuoides)

Moderate

South American dwarf cichlid

The Cockatoo Cichlid is a small South American dwarf cichlid valued for its personality, breeding behavior and colorful finnage. Apistogramma cacatuoides is generally adaptable when provided with clean, stable water, cover and a soft substrate. Males are larger and more vividly marked than females, while pairs become territorial around spawning sites. The supplied “red” designation most likely refers to a selectively bred color form; exact strain and sex confirmation cannot be established from the listing alone.
Discus (Symphysodon aequifasciatus) Care Guide

Difficult

South American freshwater cichlid

Symphysodon aequifasciatus is a large, laterally compressed cichlid from the Amazon Basin, valued for its calm behavior and striking disc-shaped body. It requires warm, clean, stable water and careful feeding, making it better suited to experienced aquarists. The supplied images show yellow, orange, red, white and dark color forms; cultivated strains can vary considerably, so exact variety identification from images alone is uncertain. Discus are social fish and generally thrive in groups rather than as isolated specimens.
Cape Lopez Killifish (Aphyosemion australe)

Moderate

West African non-annual killifish

The Cape Lopez killifish is a small, peaceful West African freshwater fish prized for its patterned body, flowing fins and manageable size. It inhabits slow-moving and temporary waters around coastal Gabon, including the Cape Lopez region. The supplied trade description identifies a pair as “Cape Lopez splendid carpets,” but this wording may describe a commercial strain rather than a formally recognized taxon. The image appears to show an orange form, so exact strain identification should be confirmed with the breeder or supplier.
Burton’s Mouthbrooder (Astatotilapia burtoni)

Moderate

East African haplochromine cichlid

Burton’s mouthbrooder, Astatotilapia burtoni, is a moderately aggressive East African haplochromine cichlid known for strong social hierarchies and maternal mouthbrooding. Males become more vividly patterned and defend territories, while females are generally less colorful and carry eggs and fry in the mouth. A pair requires a spacious, well-filtered aquarium with rocky cover, alkaline water and carefully selected tank mates. The supplied identification is consistent with Astatotilapia burtoni, although sex and locality form cannot be confirmed from the photographs alone.
Cyrtocara moorii (Blue Dolphin Cichlid) Care Guide

Moderate

Lake Malawi haplochromine cichlid

Cyrtocara moorii is a large, distinctive haplochromine cichlid from Lake Malawi, recognised for its blue adult coloration and rounded forehead, which becomes more pronounced with age. It is a maternal mouthbrooder and is generally less aggressive than many Malawi mbuna, but its size and territorial breeding behaviour require a spacious aquarium. The supplied images appear consistent with blue C. moorii, although photographs cannot confirm sex, locality, or whether the fish form a true bonded pair.
Blue Dwarf Gourami Pair (Trichogaster lalius)

Easy - Moderate

Peaceful labyrinth fish

The blue dwarf gourami is a selectively colored form of a small labyrinth fish native to the Indian subcontinent. It spends much of its time in the upper and middle aquarium, using its specialized labyrinth organ to breathe atmospheric air. Males can become territorial, especially when nesting, so a planted aquarium with calm tank mates, gentle flow, and surface cover is important. The supplied name uses Trichopodus lalius; Trichogaster lalius is the commonly used current combination.
Blue Acara (Aequidens pulcher)

Moderate

South American freshwater cichlid

The supplied label identifies these fish as Blue Acara, Aequidens pulcher, a South American freshwater cichlid often placed in the genus Andinoacara in current aquarium literature. The photograph is consistent with a blue acara, although a definitive identification cannot be confirmed from one image alone. This pair requires a spacious aquarium, stable water quality, hiding places and careful observation during breeding, when territorial behavior becomes stronger.
Julidochromis transcriptus: Black-and-White Slender Cichlid

Moderate

Lake Tanganyika rock-dwelling cichlid

Julidochromis transcriptus is a small rock-dwelling cichlid from Lake Tanganyika, recognized by its compact, elongated body and irregular black-and-white pattern. It is a territorial cave dweller that is best kept as an established pair in a carefully structured aquarium. The supplied fish are identified as a DNZ pair, although sex, collection locality, and precise geographic form cannot be verified from the supplied material alone.
Azur Cichlid (Sciaenochromis fryeri) Care Guide

Moderate

Lake Malawi haplochromine cichlid

The Azur cichlid is commonly sold as Sciaenochromis fryeri, a predatory haplochromine cichlid from Lake Malawi. Mature males develop vivid electric-blue coloration, while females and juveniles are generally less intensely colored. This fish is moderately aggressive and needs a spacious aquarium with rocky structure, alkaline, mineral-rich water, and carefully selected tank mates. The supplied source describes a DNZ pair, but sex and exact locality cannot be confirmed from the images alone. Identification confidence is therefore good but not absolute.
Marble Angelfish (Pterophyllum scalare)

Moderate

South American freshwater cichlid

The marble angelfish is a captive-bred color form of Pterophyllum scalare, a tall-bodied South American cichlid valued for its elegant fins and distinctive irregular black patterning. It needs a mature, spacious aquarium with excellent water quality, warm water and suitable tank mates. Although generally manageable, adults establish territories and may become assertive when pairing or spawning. The supplied source identifies two marble angelfish; exact lineage and strain details cannot be confirmed from the available information.
Gold Angelfish, Pterophyllum scalare

Moderate

Freshwater South American cichlid

The Gold Angelfish is an ornamental colour form of Pterophyllum scalare, a tall-bodied South American cichlid valued for its graceful movement and parental care. It needs a mature, spacious aquarium with substantial vertical clearance, stable warm water and carefully chosen tank mates. The supplied source identifies two fish as Gold Angelfish, although the accompanying images show several angelfish colour and fin forms, so the exact appearance of the supplied specimens cannot be confirmed from the images alone.
Zebra Angelfish (Pterophyllum scalare)

Moderate

South American freshwater cichlid

The Zebra Angelfish is a selectively bred form of Pterophyllum scalare, recognised by a silvery body with several dark vertical bars and the tall, laterally compressed shape typical of freshwater angelfish. The supplied images also show other angelfish colour forms, so the exact appearance of the listed pair cannot be confirmed from the image set alone. This South American cichlid is generally manageable for experienced community keepers, but its size, territorial breeding behaviour and need for a tall aquarium should be planned for carefully.
Black Angelfish (Pterophyllum scalare)

Moderate

South American freshwater cichlid

The supplied record identifies two black angelfish, most likely a domestic color form of Pterophyllum scalare. The photographs show several angelfish color patterns, so they should not be treated as proof that every pictured fish is black or that all belong to the same strain. Black angelfish retain the tall, laterally compressed body and extended fins typical of freshwater angelfish. They need a tall, mature aquarium, stable warm water, a varied diet, and carefully selected tank mates.
White Marble Angelfish (Pterophyllum scalare)

Moderate

Freshwater cichlid

The white marble angelfish is a selectively bred aquarium color form of Pterophyllum scalare, a tall-bodied South American cichlid valued for its elegant fins and distinctive irregular dark marbling. It is generally peaceful when young but can become territorial, especially when paired for spawning. Successful care depends on a tall aquarium, excellent water quality, suitable tank mates, and a varied carnivorous-omnivorous diet. The exact genetic strain shown cannot be confirmed from photographs alone.
Freshwater Angelfish Mix (Pterophyllum scalare)

Moderate

Freshwater cichlid

Freshwater angelfish are tall-bodied South American cichlids valued for their graceful movement and wide range of captive color forms. The supplied source identifies a mixed group as Pterophyllum scalare; the photographs show several forms, including striped, black, orange, white, silver and blue-toned fish. They are manageable for experienced beginners, but their adult height, territorial breeding behavior and tendency to eat small tank mates require thoughtful aquarium planning.