The Altum Angelfish Pterophyllum altum is the largest of the three described angelfish species. They measure about 7 inches (18 cm) in length but are very tall, with extensive fins reaching up to around 9″ (20 cm) in height. Although larger than its close and well known relative, the common Silver Angelfish Pterophyllum scalare, this disk shaped cichlid is very elegant and graceful. It is also known as the Orinoco Angelfish, Atlum Angel, and Deep Angelfish.
The Altum Angelfish is very similar to the wild form of the other angelfish species. But It is larger both in length and in height. It generally reaches about 7 inches (18 cm) in length and is about 9 inches (20 cm) in height from the tip of the dorsal fin to the tip of the anal fin. There are some reported anomalies of wild specimens reaching up to 19.6 inches (50 cm) in height and some aquarium specimens said to reach over 15.75 inches (40 cm) in height.
The body is laterally compressed with a distinctive diamond shape and steep forehead with a a “notch” on the upper part of its snout, just above the nares, and a steeply rising forehead. They have oversized extended dorsal and anal fins which, along with the tail fin, tend to be very long and flowing. In mature fish the tail fin can develop streamers on the outside corners. The Pelvic (ventral) fins are also very long and delicate. They can have a lifespan of 10 -15 years when properly cared for in a well maintained aquarium.
The body presents a general silver coloration which may be accented with a greenish tint. Three broad dark brownish/redish bars run vertically along the body in addition to some less prounounced and fainter bars. The fins can show red striations and adults may have some red spots and a blue-green cast to the dorsal fin. When aroused they will exhibit a black spot on the gill cover.
There are also hybrids being developed by cross breeding the P. altum with P. scalare and called the “Orinoco Altum”. These hybrids may or may not show the notched trait of the true species, or may have it to a lesser degree.
Size of fish – inches: 15.8 inches (40.01 cm) – The Altum Angelfish generally reaches a length of about 7 inches (18 cm) in the aquarium, with a height of up to about 8.87 inches (20 cm) from the tip of the dorsal fin to the tip of the anal fin. However there are reports of their height reaching up to 19.6 inches (50 cm) in the wild, and specimens in the aquarium have reportedly been grown to heights of over 15.75 inches (40 cm).
Lifespan: 15 years