Pterophyllum altumPELLEGRIN 1903
Type Locality: Atabapo, Río Orinoco, Venezuela
Range: Amazon River Basin: the upper Negro River drainage; Orinoco River Basin: tributaries of the upper Orinoco River (Inírida and Atabapo rivers) to Puerto Ayacucho
Taxonomic Troubles: This is the original name. Beware that various populations of P. scalare are being sold as altums, e.g., “Peruvian altums.”
Size: 18 cm (7 inches) long and up to 30 cm (12 inches) tall.
Preferred Water Chemistry: Tropical freshwater, very soft and very acidic (pH 4.2 to 6.2). Best to keep the temperature above 28°C (82°F).
Difficulty: An extremely difficult species to maintain, and even more difficult to spawn. The most success has been with extremely soft and acidic water of perfect quality. This fish has no tolerance for dissolved wastes. The altum angel is suitable only for advanced
Tank Setup: Plants and wood will provide necessary cover for this skittish species. A very large (and high) aquarium with powerful filtration and frequent, large water changes are required.
Feeding: A carnivore and stealth predator. Newly imported specimens will probably require live foods, but once they are feeding well they will usually take frozen foods as well. Like their cousins P. scalare, they will eat any tankmates small enough to ingest, met
Breeding: The altum frustrates hobbyists trying to spawn them. In many cases where a pair is induced to spawn, they do so only once and then never again despite a full arsenal of tricks such as massive water changes, temperature changes, plenty of live food, etc. Virtually all specimens in the trade are wild caught.
Description: A striking fish with bold vertical stripes and massively long dorsal and anal fins. Light browns and dark chocolates occur in place of the silver and black colors of the common angel P. scalare.
Notes: This is the Holy Grail for many cichlid fans. Expensive and hard to find, this fish is just about the opposite of the common angelfish: While P. scalare is hardy, adaptable, and easy to spawn, P. altum is delicate, finicky, and near-impossible to spawn. There are those who say that the regular angelfish was like that at first, but today many aquarists bring in wild-caught scalares and breed them, while altums still thwart just about everyone. It will undoubtedly be better once a reliable breeding protocol is established and we have tank-raised altums to work with, but they are still likely to be difficult fish. It is very important that you report any success with this species so that other hobbyists can benefit from your findings.