Peruvian Altum

Peruvian Altum


The Peruvian Altum... it's NOT an Altum, it's Scalare
By Michelle Ricketts/Dr. David Schleser

May 28,2000-The Peruvian angels with the altum-like shape are from the Rio Nanay, just outside of Iquitos, Peru. I am very familiar with the Rio Nanay angels from Peru, as I lead tropical fish study and collecting trips to this region every year, and will be going there again the month of July. In my travels through Amazonian Peru and Brazil I have collected many angelfish - all scalare. Like so many other fish angels vary considerably in appearance within their large range.

Most of the angels that we catch in the Peruvian Amazon and its tributaries develop quite a bit of green iridescence on the gill plate and upper portion of the body as they mature. My colleague and friend Dr. Paul Loiselle, author of numerous cichlid articles and books, and curator of fishes at the New York Aquarium, has always been fascinated by this coloration. Very different from the usual run of normal colored aquarium strains. I have always wondered if these were the wild types used in creating those iridescent greenish and blue aquarium strains.

About the Peruvian Angels with altum appearance... that was anecdotal experiences gained from collecting them throughout a fairly wide area of Amazonia, and seeing specimens from many locations in exporters' facilities down there. The Nanay fish are a real puzzle, and I wonder if they are really native to this river.

You see, in the 70's an exporter's facility was flooded out and all his fish were released into the Nanay. This is how discus reached this river that is upriver from their normal range that ends at the Putumayo (the border of Peru with Columbia, 2 days boat ride down river from Iquitos). In the 80's local tropical fish collectors started catching discus in the Nanay descended from this accidental introduction. It is possible that this very distinct strain of scalare might have reached this river the same way. You realize that this is pure speculation. All angels that I have caught nearby, but not in this river, look much more like standard wild angels.

Another point to note is that the Nanay is a blackwater river (that is why the discus did so well), and angels tend to be a whitewater or clearwater fish, shunning the strongly acidic blackwater tributaries. Very similar appearing angels have been imported regularly from Columbia, but I do not know the locality of capture.

As far as I know there is no evidence that the various species of angelfishes hybridize - in aquariums or in the wild. As to the number of "true" species, that is still open to dispute. Some feel that what we call scalare might be in fact a number of different but similar species. Since scalare is found from Peru all the way to Belem, and in many of the Amazon's tributaries, this might be found to be so. This is exactly what we are finding in severum and festivum cichlids. Each of these former species have now been broken up into several separate species (not subspecies). Eimeki is generally accepted to be a synonym of scalare. The only place where altum and scalare MIGHT possibly overlap in ranges is the middle Rio Negro. Leopoldi is said to be Peruvian but I have never caught it. Kullander thinks that this long bodied angel is the link between the genera Pterophyllum and Mesonauta (the festivums). Cross breeding or selective breeding of local variants is not the same thing as creating a hybrid. However, they should never be released within the range of the species, since you have modified local genetic makeup by cross breeding fish from 2 different populations.

You might be interested in learning that the notched forehead profile is distinctly noted in the type description of scalare. According to Sven Kullander, Dumerilii is a synonym of scalare, and what we call dumerilii is really leopoldi.

Red Spotted Angelfish

The red spots are found on most wild adult angels and are not due to parasites. They fade in color while in captivity if the diet lacks carotene precursors of the red pigment. This is a very similar situation to the beautiful red spotting found on Peruvian green discus fish. If you see tiny black dots on a wild angels fins and body, or small pin point size pimples, these are most probably the encysted larvae of digenetic flukes. In order for them to reach maturity the fish has to be eaten by the final fluke host. This is usually a large water bird or mammal. They therefore can not reproduce in an aquarium, do no harm, and eventually disappear. Wild silver dollars are often similarly parasitized.

David Schleser

Note: more information on wild angelfish available at TBA

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