Freshwater Angelfish – Unique Traits of a Common Aquarium Fish

Hello, Frank Indiviglio here.  It seems to me that we sometimes take common aquarium fishes for granted, and overlook the fact that all are uniquely adapted to life in wild.  The Freshwater Angelfish (Pterophyllum scalare), is a case in point.

Functional Beauty

Named for the long, trailing fins that accentuate the height and graceful appearance of the laterally-compressed body, the Angelfish is one of the most universally recognizable and beloved of aquarium species.  Their flattened shape is a unique adaptation that sets them apart in a family of fishes known for their unusual lifestyles, the Cichlidae.  The slender body form and dark lateral bands superbly suit this fish for life in the reed beds that form its natural habitat. 

Angelfishes adapt to a variety of captive habitats, and so are often displayed in a typical “community aquarium”. However, they are most at ease in tanks heavily planted with Vallisneria and other grasses, where their grace in swimming about the vegetation can best be seen.  I kept a group in this manner at the Prospect Park Zoo, and was amazed at the range of behaviors they exhibited when compared with those I had observed in other situations.

Angelfishes in South America

The Angelfish known to the aquarium trade, Pterophyllum scalare, hails from the Amazon and Negro River systems of South America and has been recorded in Brazil, Columbia, Peru, Guyana and French Guiana.

A second species, the Deep Angelfish (Pterophyllum altum), is limited in range to the Orinoco River system of Venezuela, and is rarely to be found in the pet trade.  While on field research in Venezuela, I seined along a tributary of the Orinoco where the Deep Angelfish was said to occur.  I found enough interesting fishes to occupy me for a lifetime (including an old favorite, the Electric Eel), but have yet to find a wild Deep Angel.

Captive Care

Angelfishes prefer slightly acidic water (pH 6.8) and are highly carnivorous. They will accept a wide variety of frozen and flake foods, but do best when live foods form the mainstay of their diet. Daphnia, blackworms, brine shrimp, tiny crickets and other insects and the fry of Guppies and other Livebearers are favorites.

Sexing and Breeding

Even among adults, the sexes are somewhat difficult to distinguish.  Well-experienced aquarists are able to discern a difference in the shape of the lower edge of the body, in the area between the long, slender ventral fins and the single long anal fin.  In the male, the body’s edge slopes gently downward from the lower jaw to the anal fin, without changing shape very much.  The female’s body curves outward from the jaw to the anal fin, and then shoots downward in a 90 degree angle.  Another method of determining sex is to maintain a small group and allow them to pair-off naturally.

Well-acclimated pairs will spawn readily, if given the proper environment.  Adults held for breeding should be preconditioned with live food of various types, and, of course, housed in a secure environment without competing fishes.  Gravid females prefer to lay eggs upon plant leaves, but will also use flat pieces of slate and shale. 

Angelfishes devote extraordinary efforts to the care of their eggs and fry.  More on that, and on rearing the young, next time.  Until then, please write in with your questions and comments. 

 

Thanks,

Frank Indiviglio

Further Reading

You can read more about the natural history of the Angelfish Here.

This Video clearly shows a pair of Angelfish spawning.

Altum Angelfish images referenced from wikipedia and originally posted to flickr by Jeff Kubina and uploaded by JohnstonDJ