Like most people I have been tempted to obtain this colourful livebearer but what a minefield the subject is(especially if you want the real thing and are not interested in hybrids)!!! I have searched the net and have extracted the following info which may be of use when deciding whether or not to shell out your hard earned:
In 2006 the Endler was given a formal scientific name after scientists completed a study of the species comparing it to the common guppy.
Poeser, Kempkes and Isbrucker named the Endler as Poecilia wingei in a paper in the journal "Contributions to Zoology".
Endlers R Us Classification System (ECS)(They "appear" to be the "authority" when it comes to enders): They have three catagories:
Class N endlers can be proved to have originated from Laguna de Patos and various other bodies of water in Venezuela - this includes all subsequent progeny.
Class P endlers are endlers that contain all known characteristics of the species, but whose origins cannot be determined/proved.
Class K endlers are those who have been crossbred to other livebearing species(ie the Guppy).
Each class has its own strains. Some examples of strains are the black bar strain found in Class N livebearers, the Dutch green found in Class P and the hybrid tiger found in Class K. As can be observed, the strains in Class N are similar to those in Class P, though those in Class P tend to be bred for a specific characteristic such as green body rather than overall color. Class K endlers have morphological differences, with longer fins that tend to appear similar to a guppy's fins.
The male is only about ¾ of an inch to seven eighths of an inch (about 2 cm). The colour is what is so eye catching. The male fish has red, orange, black, green, and blue. The females colour is little different from the wild female guppy. According to Dr Endler metallic green was the only colour that could clearly be seen by prospective mates in its natural habitat - this being a phenononom he observed in wild populations of guppy also living in algae coloured waters.
The species was first collected from Laguna de Patos in Venezuela by Franklyn F Bond in 1937, and rediscovered by Dr John "Endler" in 1975. The latter were the first examples of this fish to make it to the general aquatic trade. More have been collected since then, notably by Armando Pou(Who appears to pass on the fish from his numerous trips to Swampriver Aquatics), to expand the gene pool. The original Laguna de Patos(Venezuela) population is threatened by pollution from a nearby rubbish dump.
Dr. Endler subsequently noticed (and was disappointed by the fact that)the extreme variety of colors in the wild were eliminated by the time they reached the general aquatic community and had been linebred for "type". 10% of the fish he originally collected had black pectoral fins - rarely, if ever, seen in fish offerred for sale.
Endler's livebearers are hardy and undemanding in the aquarium though they prefer hard, warm water. The warmer the water, the faster they will grow; however this also seems to shorten their lifespan. They can be kept at 18–29 °C (66–82 °F), but their optimum temperature seems to be 24–27 °C. This is slightly higher than guppies which prefer 23–25 °C.
They do best if kept in planted tanks to give the fry a better chance of survival. Endlers are good jumpers, so a cover on the tank is recommended to protect your investment.
Best of luck in your search for "originals".