Natural Hibrid

Natural Hibrid


Scalare, Leopoldi or Natural Hybrid ?
By Michelle Ricketts

May 28,2000- As some of you know, I have been trying to collect information on the possibility of natural hybridization in the wild. It has become clear that there is no evidence of this occurring. There are however, many local variants of species, and for them to cross breed or be selectively bred is not the same thing as creating a hybrid.

What has become evident is that some experts feel that there are many species yet to be discovered, in more than one genus. Some feel that what we call scalare might be in fact a number of different, but similar species. (Dr. Sven O Kullander, Senior Curator, Dept. of Vertebrate Zoology, Swedish Museum of Natural History). See "Guide To South American Cichlidae".

I contacted Dr. Wayne Leibel, Dept. of Biology, Lefayette College, Easton, PA. also an ACA Chairman. This is what he had to say in an e-mail he sent me regarding the possibility of hybridization in the wild: "Sorry to say, all I know about wild angelfish was summarized in a multipart for Aquarium Fish Magazine a few years back in my "Goin' South" series. As for hybrids I have read nothing in the scientific/ichthyological literature. There was some recent controversy when the Peruvian scalare made an appearance with its altum like facial profile, but it is not altum. My friend Dave Schleser who has been to the Peruvian Amazon probably 20-30 times just this weekend showed a slide of the fish and said it is a restricted population in the Rio Nanay, I believe. I know that Marc Weiss the discus king has written extensively on the subject of apparent natural hybridization between S. heckel and S. aequifasciata, so it may well happen between angel pops that come into contact, though certainly there is geographic variation in P. scalare that makes them look like distinct species when, really, they are not."

After speaking with Dr. Leibel, I contacted Dr. David Schleser about his peruvian angel. He has lead tropical fish studies and collecting trips to the Amazon region every year for the past 20 years. From speaking with David, I was able to understand the story behind this mysterious Peruvian Angelfish. What he had to say was extremely interesting and thought provoking.

"Peruvian Angelfish"  A scalare with an Altum-like Appearance

"Red Spotted Angelfishes" Parasitic or not?

Sept. 7, 2000

A member of the Angelfish Society had posted to the forum about his wild dumerilii and wild juvenile leopoldi and stated that they varied in appearance. He mentioned that the two species were synonymized with one another and should be similar in appearance, but they were not. It is true that they were synonymized with one another by Schultz in 1967. However, Dr. Sven O Kullander reviewed the genus in 1986 and synonymized P. Dumerilii with P. Scalare. Then recognized the P. Leopoldi as a distinct specie (see Kullander's "Guide to South American Cichlidae"). Many of today's angelfish hobbyists have been unaware of Kullander's review.

I had discovered Dr. Kullander's site a few months earlier and had learned of this review. When this subject finally came up in September, I shared this information in a response to the poster. This generated much more discussion on the status of our wild populations. To further inform everyone of the "state of confusion" I mentioned the conversations I had with Dr. David Schlesser and referred people to his comments I had posted on my site.

"In my attempt to explain "local variants of the Pterophyllum species" (ie...coloration, body shape, freckling, ...some have a spot behind the eyes, some don't, etc.), it became apparent that the best way for people to understand was to show them in a photographic format. I gathered photographs from a few magazines and books that I had lying around. The photographs clearly showed one of two possibilities. Either the fish that were printed in these books were variants or they were miss-identified.

The possibility of them being miss-identified brought on further discussion. It was thought by conservationist and hobbyist alike, that our domestic angelfishes were 100% scalare. Breeders were implementing wild blood into their domestic lines and thought that they were using the P. scalare specie. However, people did not know that the P. scalare specie is defined by having a notched pre-dorsal contour. Most of the wilds that breeders used in their breeding program did not have this characteristic. In fact, when they were compared to other breeders wild stock, they all varied significantly in appearance. Some thought that P. scalare did not have to possess the notched pre-dorsal contour to be a scalare. It was thought that these types of fish were most likely a scalare variant. It is possible that they might be a variant, but there is not any conclusive evidence to say that they are. What they also did not know was that, according to Dr. Sven O Kullander, that there was obviously other species of angelfishes yet to be discovered. In knowing this, we can only conclude that any wild angelfish that 1.) does not poses the "notched pre-dorsal contour", 2.) are obviously "not" an altum, but could either be a leopoldi, or an "unknown" specie.

Therefore, it became evident, that many of the wild angelfish that had been imported were miss-identified and that there truly was the possibility of other "unknown" angelfish species." By understanding this, we cannot positively identify our domestics as being of pure scalare bloodlines. The probability of them being hybrids between two or more species is very high.

Sept. 7, 2000

Below are some closing statements from Steve Rybicki.

The Angelfish Forum
Classification of wilds
Posted By: Steve Rybicki
Date: Thursday, 7 September 2000, at 10:39 p.m.

I wanted to add my thoughts on this subject.

First, I'd like to say that fish are frequently mislabeled when they are imported, so we really can't use that to determine what we have. Just because you import it as a P. scalare doesn't mean that it is one. To attempt to categorize an angel you will have to go to the classification literature and look at the meristics data. If your fish matches that, it still doesn't mean it's that specie (but is at least closely related).

Even after a fish is classified there is no way to be sure it is correct. The science of cladistics is full of assumptions and guesses. As new data becomes available, they are renamed and reclassified frequently.

In the past a systematist typically used hard structures (meristics) to classify an animal. Today they have the tool of DNA profiling to help and even this presents it's own set of problems in interpreting the DNA sequence. Another useful tool is analyzing behavior, though is difficult to do with a specimen that's been simmering in preservative for 50 years. All this makes for some heated debate among the scientists who do this for a living.

What this boils down to is that we have multiple wild-types that appear to be physically different. When I say this, I'm not referring to color. Typically classification is determined, by bones, scales, fins, etc. differences. A scalare without a strongly concaved predorsal contour is not a scalare. It may be labeled a scalare but it is something else according to our current classification - possibly a subspecie or maybe something that should have it's own specie name. So, they are physically different, but we only have 3 names to apply at this point. I believe after the scientists get through studying this more thoroughly we will have more species named, but even if we don't, we will still have the problem of applying correct specie names to the many different looking fish available to us.

As to what our domestics are - it is common to see those with notched predorsal contours, those with straight predorsal contours and those somewhere in the middle. Scale counts vary quite a bit, and I don't doubt the fin ray counts are variable. This doesn't even take into consideration that many structural mutations have taken place in our ornamental populations. I think it is almost inconceivable that they are anything other than a mix of many different genes, both wild-type of different species and those mutated and perpetuated in captivity.

As for the fish I'm labeling as P. leopoldi. I really don't know if that is accurate. All I do know for sure is that it is clearly not a scalare or an altum. They do not match the meristic data for those two.

More information on wild angelfish and domestic angelfish can be found at TBA

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