Altum Angelfish

A characteristic feature of this species is its rhomboid body shape, which is strongly flattened laterally and possesses significant height, reaching about 18 cm, and a length of up to 20 cm. The impressive dimensions of the fish are due to its long dorsal and anal fins. The predominant coloration is silvery with a slight greenish tint. Broad vertical dark brown stripes run across the body, extending onto the fins. Sometimes a red hue can be observed, particularly distinct in the caudal fin's edging.

The natural range of the species is narrow: the upper Rio Negro in the Amazon basin and tributaries of the upper Orinoco — the Inírida and Atabapo rivers in Colombia and Venezuela. The fish feel most comfortable in the floodplains of rivers, where the current is moderate, and the water is very soft and rich in oxygen. They prefer to stay near the shoreline, which is densely overgrown with plants and provides many natural shelters in the form of roots and submerged tree trunks. In their natural environment, these fish are omnivorous: their diet consists of small fish and invertebrates, as well as plant components.

Among the many angelfish species, this one stands out for its relatively peaceful nature. It can coexist with most calm aquarium inhabitants; however, as they age, fish exhibit territorial behavior and can become aggressive, especially noticeable during spawning. When choosing tank mates, it's worth remembering that at a young age, until the angelfish reaches its maximum size (approximately up to 5 years), other peaceful species or members of its own kind can quite well coexist with it. An adult will eat anything that fits in its mouth — neon tetras, guppies, pygmy rasboras — so small tankmates should not be added.

This fish species is extremely demanding regarding its aquatic environment: the water must be very soft and acidic. Any changes in the hydrochemical composition negatively affect their health. At least 25% of the water must be renewed weekly, and before adding, ensure that the parameters of the fresh water match those of the aquarium. It is also important to create an artificial current in the aquarium, which is achieved by installing powerful filters; it is advisable to use alder cones as a filter material, as they help to increase acidity. A good aeration system is no less important, as Pterophyllum altum is very sensitive to oxygen levels. Essential equipment also includes a heater and lighting. When decorating the aquarium, preference should be given to numerous shelters arranged around the perimeter: driftwood, roots, stones, and grottoes. It is advisable to leave enough free space in the central part for swimming. Any plants capable of growing in these conditions can be used, as the fish are not prone to damaging them.

These fish are omnivorous and readily consume various types of food: both dry commercial mixes and live or frozen products. A key condition for successful keeping is maintaining a varied diet with a daily combination of different types of food. It is recommended to feed the fish 2–3 times a day. It is important to remove all uneaten food within five minutes to prevent overeating, fat accumulation, and subsequent digestive problems.

Breeding this species in a home aquarium presents significant difficulties and is practically impossible. This is due to both the challenges in determining the sex of individuals and the need to create specific external conditions that are extremely difficult to reproduce outside their natural habitat.

Pterophyllum altum is susceptible to most common diseases. Even minor changes in living conditions can provoke various ailments. The most frequent problems are ichthyophthiriasis and external parasite infestations.

When selecting individuals, preference should be given to fish with active behavior and clean skin without signs of film, spots, or fin damage. It is important to assess the overall condition of the group in the store: the fish should show curiosity, rather than hiding in corners or lying on the bottom. Avoid purchasing specimens with sunken bellies or signs of emaciation, as this species tolerates adaptation after transportation extremely poorly. It is recommended to ask the seller about the origin of the fish, as wild-caught individuals require specific keeping conditions and adapt to the aquarium environment more difficultly than those bred in captivity.