Flameback bleeding heart tetra

Geographical Origin & Biotope:

Endemic to a highly restricted region within the upper Rio Negro basin in Amazonas, Brazil, specifically documented in the Rio Ererê. Hyphessobrycon pyrrhonotus (the Flame-back Bleeding Heart Tetra) is a highly specialized blackwater species. It naturally colonizes deeply shaded, extremely slow-moving or stagnant marginal swamp pools and flooded igapó forests. These pristine environments are defined by intensely tea-colored, acidic water flowing over pure white sand heavily blanketed by decomposing leaf litter and submerged root tangles.

Taxonomy & Morphology:

Scientifically classified within the Characidae family, it belongs to the famous "Rosy Tetra" clade within the Hyphessobrycon genus. Taxonomically, its specific name "pyrrhonotus" translates from Greek as "fire-backed," perfectly describing its unique distinguishing feature. Morphologically, it shares the classic Rosy Tetra profile: a deep, laterally compressed, almost disc-like body shape, a small upward-facing mouth, and the characteristic adipose fin.

Social Behavior:

They are peaceful, somewhat timid, and obligate schooling fish. Due to the dark, predatory environments they inhabit, their entire social structure relies on the safety of a group. A minimum school of 8-10 individuals is absolutely mandatory; keeping fewer will induce chronic stress, lethargy, and a complete loss of coloration. Within a large school, dominant males will establish loose, temporary mid-water territories, engaging in stunning, rapid-fire sparring displays by flaring their massive dorsal fins.

Coloration & Sexual Dimorphism:

Sexual dimorphism is distinct in mature adults. Females are deeper-bodied and plumper, possessing shorter, more rounded fins and slightly muted colors. Males develop spectacular, vastly extended, sweeping dorsal and anal fins. The coloration is breathtaking. The base body is a translucent, rosy-peach. Like the standard Bleeding Heart Tetra, it features a vivid crimson spot on the flanks. The defining feature, however, is a blazing, fiery blood-red stripe running continuously along the entire top ridge of the back.

Tank Setup:

The aquarium architecture must meticulously replicate a claustrophobic, pitch-black Amazonian blackwater pool. A heavily shaded environment is absolutely mandatory to unlock their blazing red colors. The tank MUST feature dimmed lighting, completely shielded by a thick canopy of floating plants (like Salvinia). The substrate should be soft sand, heavily carpeted with Indian Almond Leaves and extensive bogwood tangles. Bright lights or bare tanks will cause terminal stress and pale coloration.

Diet & Feeding:

In their natural blackwater pools, they are highly effective micro-predators, hunting tiny zooplankton, aquatic insect larvae, and microscopic worms among the leaf litter. In captivity, they are unfussy, mid-water feeders that eagerly accept all standard high-quality dry foods. To maintain their spectacular glowing red back and lateral spot, their diet MUST be heavily supplemented with color-enhancing live or frozen foods, particularly Daphnia, Cyclops, and bloodworms.

Water Quality:

Originating from the pristine upper Rio Negro, they are extreme blackwater specialists. They demand warm tropical temperatures (24-28°C) and strictly require very soft, highly acidic water (pH 5.0 - 6.5) heavily saturated with botanical humic acids to thrive. They will physically survive in harder, neutral water, but their immune systems will crash and their colors will fade to a dull grey. Because they inhabit stagnant pools, filter flow must be exceptionally gentle and baffled.

Compatibility & Tankmates:

They are excellent, peaceful community fish for specialized blackwater setups. Due to their deep bodies, they are slightly less vulnerable to predation than Neon Tetras. Excellent tankmates include other soft-water characins (Cardinal Tetras, Rummy-nose Tetras), dwarf cichlids (Apistogramma, Rams), and small bottom-dwellers (Corydoras, Otocinclus). You MUST avoid aggressive fin-nippers (like Tiger Barbs) that will ruthlessly shred the males' spectacular flowing dorsal fins.

Aquarium Breeding:

Breeding is exceptionally difficult and strictly requires perfect blackwater conditions. They are egg-scatterers. To breed, condition a pair and move them to a completely darkened breeding tank containing water with a pH around 5.5, zero hardness, and large clumps of Java Moss. Following a high-speed courtship, they will scatter hundreds of adhesive eggs. The parents are ravenous egg-eaters and MUST be removed immediately. The eggs are highly light-sensitive.

Risks & Diseases:

Physically, they are relatively hardy if kept in large groups in soft water. The absolute greatest risk is keeping them in hard, alkaline tap water. Without the protective, antibacterial properties of blackwater tannins, their slime coat degrades, making them highly susceptible to fungal infections and severe outbreaks of Ich (white spot). They are also prone to stress-induced fin rot if kept with aggressive tankmates or in strong filter currents.