The Altum Angelfish is a very pretty and peaceful cichlid despite its large size!

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 that make it 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.

P. altum is distinguished from other angelfish species by having a “notch” on the upper part of its snout rather than the flat or slightly rounded forehead found in the other two species. In color and pattern, however, it resembles these other species with a silver body and dark stripes that are brownish-red. 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. Overall color differences can often be subtle, but all true P. altum will have a notch above the nares.

In the past, only wild-caught specimens of this fish were available. This was due to a high mortality rate that, for years, made the fish practically impossible to breed. More recently, however, it has been successfully bred by some hobbyists, and captive-bred specimens are now occasionally available along with the wild-caught. Hybrids are also being developed by cross-breeding the P. altum with P. scalare. The resulting hybrids are called “Orinoco Altum” and may or may not have the notch found on the true species, or may have it to a lesser degree.

The Altum is considered the most peaceful of all angelfish species. It is a bit timid, however, and can be frightened by shadows and fast movements. This is especially true when this fish is first introduced to a new home, but once acclimated, it is a friendly and personable fish. Though the Altum is considered a community fish, this cichlid may not be as sociable with smaller fish. They will school peacefully when they are young but tend to pair off and become more territorial when they are older.

They are moderately difficult to keep as they have more stringent requirements than common angelfish. They need enough room to accommodate their size and allow them to swim freely. A 55-gallon tank is the suggested minimum, but if you are keeping a pair or community, they will need a larger tank. They will feel most at home and comfortable in a warmer aquarium that has roots and some rocks to offer places of refuge. They also like hardy plants placed around the inside perimeter, keeping an open area in the center for swimming.


Scientific Classification


Altum Angelfish – Quick Aquarium Care

Aquarist Experience Level:Intermediate
Aquarium Hardiness:Moderately hardy
Minimum Tank Size:55 gal (208 L)
Size of fish – inches15.8 inches (40.01 cm)
Temperature:78.0 to 84.0° F (25.6 to 28.9&deg C)

Habitat: Distribution / Background

The Altum Angelfish Pterophyllum altum was described by Pellegrin in 1903. They are found in rivers in South America, particularly in the Amazon River basin in the upper Negro River drainage and the Orinoco River basin in tributaries of the upper Orinoco River (Inírida and Atabapo rivers) to Puerto Ayacucho. Other common names they are known by are Orinoco Angelfish, Altum Angel, and Deep Angelfish.

In the wild, these cichlids live in river watersheds and flood plains where there are moderate amounts of water flow, submerged tree and plant roots, and underwater vegetation. They are more frequently found in very soft,well-oxygenated waters. These omnivores feed on smaller fish and invertebrates and eat other food particles in the water.

The Angelfish species are an attractive and graceful group of fish. Besides the Altum Angelfish, there are two other recognized species in the Pterophyllum genera in addition to potentially several undescribed species. The other described species are as follows:

    • Silver Angelfish Pterophyllum scalare
      The common Angelfish sold today is generally considered to be a hybrid of Pterophyllum scalare, though this is speculation. Forms of Angelfish found in the wild have become fixed forms by captive inbreeding. The common Angelfish has historically been referred to as Pterophyllum scalare because this angelfish proved to be the hardiest and easiest to breed in captivity.

  • Leopold’s Angel Pterophyllum leopoldi
    The Leopold’s Angel must be imported to America and is fairly rare. Visually, it appears very similar to the common Angelfish but displays slightly different black bar patterning. It has a few vertical dark body bars but is distinguished by a black blotch at the base of the dorsal final that doesn’t extend into a full bar.
  • Scientific Name: Pterophyllum altum
  • Social Grouping: Pairs – When younger, they will tend to swim in larger groups but tend to pair off once they reach full maturity
  • IUCN Red List: NE – Not Evaluated or not listed


The Altum Angelfish is very similar to the wild form of the other angelfish species, but it is both taller and longer. 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 “notch” on the upper part of the 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. The tail fins of mature fish can develop streamers on the outside corners. The pelvic (ventral) fins are also very long and delicate. They can have a lifespan of 10 to 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/reddish bars run vertically along the body in addition to some less pronounced 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.

Hybrids are being developed by cross-breeding the P. altum with P. scalare. These hybrids are called “Orinoco Altum” and may or may not have the notch found on the true species, or they 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 some individuals 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

Fish Keeping Difficulty

Angelfish are one of the best known of all tropical fish and many beginning aquarists will try to start off with these fish. The Altum Angelfish can be very challenging to keep, however, and is a poor choice for beginning fish keepers. They are prone to hole-inhead disease, have trouble dealing with nitrates, and are susceptible to stress-related diseases. In addition, they are sensitive to water conditions, need very acidic and soft water, and can be very difficult to feed.

  • Aquarium Hardiness: Moderately hardy
  • Aquarist Experience Level: Intermediate

Foods and Feeding

Since they are omnivorous, the Altum Angelfish will generally eat all kinds of live, fresh, and flake foods. To keep a good balance, give them a high-quality flake food or pellet every day. Feed brine shrimp (either live or frozen) or blood worms as a treat. You can even feed them lettuce or spinach. Feed mosquito larvae very sparingly as they will tend to overeat it. Overeating can result in a buildup of fats, which results in inactivity and could kill them.

  • Diet Type: Omnivore
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet
  • Vegetable Food: Some of Diet
  • Meaty Food: Some of Diet
  • Feeding Frequency: Several feedings per day

Aquarium Care

The Atlum Angel needs a strict water change regimen of at least 25% every week. The Angel is very sensitive to water fluctuations, so make sure to test any water going back into the tank.The water needs to be soft for 0-5dH. Make sure when doing water changes to carefully vacuum the substrate thoroughly. Take great care when cleaning the tank and changing the water to not cause unwarranted or excess stress to the fish as they are prone to stress-related diseases.

  • Water Changes: Weekly

Aquarium Setup

A minimum 55-gallon aquarium is suitable for a single fish, though a larger tank is necessary for keeping more. They need good water movement along with very strong and efficient filtration. As they come from a natural environment with soft, well-oxygenated water, peat-filtered water is recommended.

Provide a warmer aquarium that has roots and some rocks to offer places of refuge. They also like hardy plants placed around the inside perimeter, keeping an open area in the center for swimming. They prefer subdued lighting. These fish do not burrow and will not damage plants as much as other cichlids.

The Altum Angelfish is more sensitive to water conditions than the common angelfish, so it is suggested for aquarists with some fish-keeping experience. Keeping this fish will be a rewarding experience for aquarists who are observant and diligent in providing care.

  • Minimum Tank Size: 55 gal (208 L)
  • Suitable for Nano Tank: No
  • Substrate Type: Any
  • Lighting Needs: Low – subdued lighting
  • Temperature: 78.0 to 84.0° F (25.6 to 28.9&deg C)
  • Breeding Temperature: 86.5° F – 86 – 87.8° F (30 – 31 ° C)
  • Range ph: 4.5-5.8
  • Hardness Range: 2 – 10 dGH
  • Brackish: No
  • Water Movement: Moderate
  • Water Region: All

Social Behaviors

Though they are considered a community fish, Altum Angelfish may become territorial as they grow older. They are reportedly a more peaceful fish than other angelfish species, but being in the cichlid family, smaller fish may not do well with them. As they mature, they will pair off, developing a strong nuclear family, and defend a territory in which to breed. A nice thing about the Altum Angelfish is that they don’t burrow or disturb plants!

  • Venomous: No
  • Temperament: Semi-aggressive
  • Compatible with:
    • Same species – conspecifics: Yes
    • Peaceful fish (): Monitor – Larger fish make the best tankmates as the angel will try to eat anything small enough to fit in its mouth.
    • Semi-Aggressive (): Monitor
    • Aggressive (): Threat
    • Large Semi-Aggressive (): Threat
    • Large Aggressive, Predatory (): Threat
    • Monitor
    • Shrimps, Crabs, Snails: May be aggressive
    • Plants: Safe

Sex: Sexual differences

There are no distinguishable differences except during breeding season when the papilla on the male is pointed and on the female is blunt.

Breeding / Reproduction

The Altum Angelfish is a difficult fish to breed. For years, it was considered impossible to breed. More recently, it has been successfully bred by some hobbyists and captive-bred specimens are now occasionally available. Hybrids are being developed by cross-breeding the P. altum with P. scalare. These hybrids are called the “Orinoco Altum.”The characteristic “notched” nose of the pure-blooded fish may or may not be present in the hybrid version, or it may simply appear less pronounced.

These fish are egg layers and form nuclear families. They are open breeders that prefer to spawn on submerged roots and tree branches in the wild. They are difficult to sex, so it’s best to start with a small school of about 4 to 8 fish and let them establish pairs.

The pair will need to be properly conditioned in very clean water to spawn. Supplement their current diet with foods rich in protein, but take care not to overfeed them. The breeding water should be soft, acidic, and warm. Have a pH between 5.8 to6.2 with hardness at 1 to5° dGH, and temperatures between 86 and F (30 – 31 ° C). The males sometimes make a loud grating sound with their jaws when mating.

The female will lay between a few hundred to over 1000 eggs on carefully cleaned leaves, and the male will follow and fertilize them. If the parents don’t eat the eggs, the larvae and fry are carefully guarded. The eggs will hatch in a few days, and the fry will be free-swimming in a week. The parents will swim with a shoal of fry in tow. The fry can be fed newly hatched brine shrimp for the first week or two. For more information and a general description of how to breed Cichlids, see Breeding Freshwater Fish: Cichlids.

  • Ease of Breeding: Difficult

Fish Diseases

Altum Angelfish are susceptible to typical fish ailments, especially if the water is stale and of poor quality and oxygenation. One common problem is Ich. It can be treated by elevating the tank temperature to 86° F (30° C) for 3 days. If that does not cure the Ich, the fish needs to be treated with copper (remove any water conditioners). Several copper-based fish medications are available for Ich. Copper use must be kept within the proper levels, so be sure to follow the manufacturer’s suggestions. A copper test also can be used to keep the proper levels. You can also combine increasing the temperature with an Ich medication treatment. Intestinal disease can be treated with metronidazol.

As with most fish, Angelfish are prone to skin flukes and other parasitic infestations (protozoa, worms, etc.), fungal infections, and bacterial infections. Aquarists should read up on common tank diseases. Knowing the signs and catching and treating them early makes a huge difference. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.

Remember that anything you add to your tank can introduce disease. Not only other fish, but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank, so as not to upset the balance.


The Altum Angelfish or Orinoco Angelfish have recently become more frequently imported, so they are regularly available online and in fish stores. They are moderately expensive and more costly than the common Angelfish. Hybrids are also being developed by crossing the P. altum with P. scalare. These hybrids are called the “Orinoco Altum” and are occasionally available but usually more costly.



Featured Image Credit: Cheng Wei, Shutterstock