The people describing the Endler's livebearers have noted that these "iridescent guppies" have a very different courting pattern and relationship between the genders. Guppy males try to attract a female guppy and that is it! Sort of one minute stands. Males of what has become Poecilia wingei continue a relationship with the females and they form a school/harem, which moves together. Several Guppyloggers have noticed that Endler's are even more tolerant of their fry than are some guppies. Perhaps that is another behavioral trait, which helps delineate them as a different species.

I agree J-ME, they are beautiful. I will park my carcass in front of a green tank (ironically similar to where Dr Endler - the famous guppy researcher - first found them). I also just goggle at the golden strain in their tank. And it is nice having some fish, which are as easy to care for as they are. :)

I would urge you to keep guppies and wingei separate though. I even would keep my strain, the so-called peacock Endler's separate from the others because they are a very neat fish in their own right, That is the strain which descended from Endler's original collection. Because of "founder's effect" where at one time there were so few males that they all breed to a certain pattern (that can also be done with wild guppies too), it is startling but neat to see a tank of identical Endler's males. There is also the sentimental attachment to the original hobby strain.

The following is a very useful site in terms of viewing some of the recent strains collected and also the history of Endler's livebearers in the hobby.

http://members.cox.net/newcomb1/endlers.html

The last entry is this reference includes a list of some of the discussions of the Endler's livebearer at Guppylog. I regret having not gotten back for one more go at RaiderFan&'s question.

http://www.guppylog.com/story/2006/8/3/183911/1905

The following article (linked in turn to the description) "Poecilia (Acanthophacelus) wingei, a true Caribbean gem", is by one of the researchers who described P. wingei!

http://www.goodeids.com/article126.html

The concept of species is being challenged in several ways. It is a little bit like the controversy over what is a planet. It used to be that a species was something which couldn't breed with another - it was "reproductively isolated." Then it was discovered that distinctive fishes from many places could interbreed with somewhat close relatives from other places. Basically rape takes place in some aquariums as males can force themselves on other females, where as in nature those females could flee up or down stream and choose to mate only with males of the right color or courting display. Furthermore Geographic species might look alike, but look-alikes from different places couldn't interbreed. Naturally occurring livebearer crosses have even created distinctive fishes from that. See the Amazon mollie below.

Because I enjoy keeping hobby strains of a number of wild type livebearers, killifish and rainbowfish and I realize how easily some can cross, I work not to let that happen or to collect eggs where different egglayers are housed together. It is hugely unethical to let such crosses out in the hobby in some cases and even where crosses are accepted, it is very unethical not to tell buyers what they are actually getting.

Many fish crossed in the lab would produce eggs, which would die at some stage, often from cancers. Some crosses do develop into adult fish, but their young are mules and sterile. In some cases those mules aren't all that sterile, especially if backcrossed to one of the parent species. In yet other cases a cross will yield a beautiful generation, but in subsequent generations colors and even vitality fade.

Platys and swordtails (different species in the same genus) live in the same river systems. However their habitats within those systems are different enough that they don't cross. Dr Gordon and others discovered as early as the 1930s that those fish could, sometimes be crossed, but that a lot of the crosses developed cancer. Much of the work done on them was done in an effort to study cancer, how it comes about and of course how it can be treated.

Dr. Myron Gordon passed away, the old New York Xiohophorus study center is gone, but the strains and work go on. See http://www.xiphophorus.org/

If we purchase a fish from a certain location, we need to realize that that place may be a shopping center or other development and that particular strain or subspecies has been lost forever. If we cross our specimens, the wild strain may be lost to the hobby forever.

So please keep your Endler's strain separate from your guppies. I would even keep some very special Endler's strain separate from other Endler's strains in the same way that I would not cross a beautiful red delta guppy strain with a beautiful green delta guppy. Even if the guppy strains could be restored, I don't want to have to take a decade of my life and six to a dozen aquariums to do that. ;)

Even what a livebearer is, turns out to be a little blurry.
http://www.guppylog.com/story/2003/11/11/203510/74

This may have raised more questions that it answered. I hope it has been of some use. I would be glad to hear from you and others if there is more to ask or share. Corresponding and researching this stuff, even just as a hobbyist, is a part of the fun (fun can equal work) and helps us all to grow in the aquarist's craft.

Oh, and J-ME, Endler's can be had fairly inexpensively if you go to an aquarium club action, especially towards the end of the festivities. Mini-auctions at meetings are even more reasonable. Aquabid has performed a great service for a lot of people, but their prices are about as high as any in the world. If you were in the (Chicagoland) area I would suggest that you grab a boyfriend (yours would be best), a cooler so the fish don't cook on the ride home and drop by. ;)

Thank you (and Raider) for the opportunity to sit down and sort some of this out.