Rio Negro Altum Angelfish (Wild)

The Rio Negro Altum Angelfish is a wild-caught Pterophyllum altum from the upper reaches of the Rio Negro in Brazil, one of the world's largest blackwater river systems. This population is distinct from Orinoco altums in its adaptation to the extreme tannin-rich, ultra-soft, highly acidic blackwater environment characteristic of the Rio Negro drainage.

Specimens from this region are among the most demanding freshwater fish available to hobbyists, requiring near-distilled water conditions with heavy blackwater supplementation, elevated temperatures, and virtually zero carbonate hardness. However, for the dedicated advanced aquarist, few sights in freshwater fishkeeping rival a group of adult altum angels in a perfectly maintained blackwater display.

This species should only be purchased by experienced aquarists who have prepared dedicated species housing with verified water parameters before purchase. Mortality in suboptimal conditions is high and rapid.

Water: Temperature 27–30°C, pH 4.5–5.5, GH 0–2, KH 0–1; 100% RO water with blackwater extract and Indian almond leaves essential. Tank: 450 L minimum with height ≥75 cm; dim lighting, dark substrate, heavy driftwood; minimal current. Feeding: Live bloodworm and artemia initially; black mosquito larvae highly recommended for conditioning; very gradual pellet transition. Breeding: Extremely rare in captivity; requires perfect water chemistry; attempts should only be made by highly experienced breeders. Compatibility: Species-only tank or with small blackwater tetras (cardinals, black neons); no other cichlids.