Peruvian Altum Rio Nanay Angelfish
Pterophyllum sp. “Rio Nanay”
 
he Peruvian Altum Rio Nanay Angelfish is a rare and elegant wild variant of angelfish collected from the blackwater tributaries of the Rio Nanay in northern Peru. While not a true Altum (Pterophyllum altum), this variety is named for its similar tall, laterally compressed body shape. These fish often feature striking vertical banding, extended dorsal and anal fins, and subtle bronze, gold, or blue hues across the body.
Known for their calm nature and impressive vertical form, Rio Nanay Angelfish are ideal for large, planted aquariums with soft, acidic water. They do best when kept in groups of 5 or more or as a bonded pair in a peaceful community.
 
Species Overview
Common Name: Peruvian Altum Rio Nanay Angelfish
Scientific Name: Pterophyllum sp.
Origin: Rio Nanay, Peru (Amazon Basin)
Maximum Size: 15–18 cm (body), up to 25 cm in height with fins
Lifespan: 8–12 years
Temperament: Peaceful to mildly territorial
Swimming Level: Mid to upper levels
Compatibility: Suited to peaceful tankmates and other Amazonian species
 
Aquarium Requirements
Minimum Tank Size: 200 litres (tall tank preferred)
Substrate: Soft sand or fine gravel
Décor: Vertical wood, leaf litter, driftwood, and tall plants
Plants: Ideal – Amazon swords, Vallisneria, and floating plants
Lighting: Soft to moderate (blackwater conditions enhance colors)
Filtration: Efficient with low to moderate flow
Tank Cover: Recommended – easily startled and may jump
 
Water Parameters
Temperature: 26–30°C
pH: 5.5–6.8
Hardness: Soft (1–8 dGH)
Water Movement: Gentle
 
Diet
Diet Type: Omnivore
Preferred Foods:
– High-quality micro pellets and flakes
– Frozen/live food: bloodworms, brine shrimp, daphnia
– Vegetable matter: spirulina flakes, blanched spinach
Feeding Frequency: 1–2 times per day
Feeding Tips: Provide variety to bring out their natural color and health
 
Breeding
Substrate spawner
Mated pairs lay eggs on vertical surfaces (plant leaves, glass, or wood)
Both parents guard the eggs and fry
Soft, acidic, and clean water is critical for success
Fry start with infusoria or powdered fry food
 
Care Summary
Care Level: Intermediate
Temperament: Calm, social
Adult Size: 15–18 cm (up to 25 cm tall)
Tank Size: Minimum 200 litres (tall layout ideal)
Water Temperature: 26–30°C
pH Range: 5.5–6.8
 
Diet: Omnivore – flake, frozen, vegetable-based
Breeding: Pair-bonded substrate spawner
Tankmates: Peaceful Amazonian species (tetras, Corydoras, dwarf cichlids)