Altum Angelfish Care Guide - Setup, Diet & Breeding

Altum Angelfish are the tallest and most striking members of the freshwater angelfish group. Their laterally compressed bodies are marked with dark vertical bands over a silvery, bronze-tinged background, while their long dorsal and anal fins create an elegant triangular profile. Extended ventral filaments add to their impressive height and graceful appearance.

Compared with the more commonly kept Pterophyllum scalare, Altum Angelfish generally have a deeper body, a steeper forehead and more pronounced vertical banding. Their size and delicate proportions make them a spectacular centrepiece for a suitably spacious aquarium.

In the wild, they move through quiet forest streams, flooded woodland and shaded tributaries, where submerged roots and vegetation provide cover. The tannin-stained water is often clear but extremely soft and acidic, and the fish use their tall shape to manoeuvre among vertical branches and plants.

Altum Angelfish are intelligent, observant cichlids with a calm but purposeful manner. They develop a social hierarchy, may form strong pair bonds and can become territorial when spawning, yet they are usually far less boisterous than many larger cichlids. Wild specimens and poorly acclimated fish can be sensitive, while captive-bred individuals are often more adaptable.

Altum Angelfish are native to the upper Orinoco River basin and its tributaries in Venezuela, with closely associated populations reported from parts of Colombia and the northern Amazon region. They come from slow-moving, warm, very soft and acidic blackwater environments in tropical South America.

A group of Altum Angelfish should have at least a 300-litre aquarium, with larger tanks preferable as the fish mature. A practical minimum for a group is about 120 cm long by 50 cm wide and 70 cm high, although extra height and swimming space are highly desirable because these fish can approach 35–40 cm in total height. Use a fine sand or smooth dark substrate, subdued lighting, tall broad-leaved plants, driftwood and vertical branches that create cover without obstructing open swimming areas. Excellent filtration, gentle circulation and stable, very soft water are essential.

Adults can reach approximately 18 cm (7 in) in body length and around 35–40 cm (14–16 in) in total height including the fins. Females are often slightly smaller and less deep-bodied than males, although the difference is not always obvious outside breeding condition.

Altum Angelfish are omnivorous predators that benefit from a varied diet. Offer a quality cichlid or angelfish pellet as a staple, supplemented with frozen or live foods such as bloodworm, mysis shrimp, brine shrimp and blackworm. Occasional vegetable matter or spirulina-based foods can provide useful variety. Feed small portions regularly and avoid relying on fatty live foods as the sole diet.

Suitable companions include peaceful, similarly sized South American fish such as larger tetras, pencilfish, peaceful dwarf cichlids, Corydoras and gentle plecos, provided the aquarium is large enough for all inhabitants. Choose tankmates that tolerate warm, soft water and avoid fin-nipping species, highly aggressive cichlids and boisterous feeders. Very small fish or shrimp may eventually be viewed as prey, particularly by adult Altum Angelfish.

Altum Angelfish form pairs within a group and spawn on a vertical surface such as a broad plant leaf, slate or aquarium glass. The female lays rows of adhesive eggs while the male fertilises them, and both parents may fan and guard the clutch. Eggs usually hatch after around two to three days, with free-swimming fry following several days later. Breeding is challenging because pairs can be difficult to establish and the eggs and fry are sensitive to poor water quality and unsuitable water chemistry.

Sexual differences are subtle. Mature males may develop a broader forehead, a more robust body and a slightly larger overall profile, while females are often somewhat smaller with a less pronounced forehead. The most reliable indication is reproductive behaviour: the female produces eggs and the male fertilises them, but visual sexing alone is uncertain.