Currently available Endler strains are classified as follows:
Class N: Any Endler’s Livebearer (and progeny) that can be shown to have originated from their native waters in Venezuela. In order for an Endler’s Livebearer to be classified as Class N careful records must be kept to show the direct link to the wild Endler’s Collected in Venezuela.
Class P: Any fish of unknown origin but appearing to be an Endler’s Livebearer based on the characteristics of size, shape and color. Because it is so difficult to document the origination of the Endler’s to those that came directly from Venezuela the majority of the “pure” stock kept by hobbyists today are considered Class P. Often fish offered for sale as Class N Endler’s are really Class P Endler’s due to the lack of documentation of the Endler’s origin.
Class K: The progeny of any Endler’s Live-bearer crossed with any other live-bearer or any hybrid strain. There have been many beautiful hybrid strains developed by tropical fish hobbyists. Some of the most popular hybrids are Tiger Endler’s, Yellow Jacket Endler’s and Paradise Endler’s. Occasionally images of Endler’s being offered on AuqaBid or eBay show that some Endler’s advertised as Class N are actually hybrids and should be classified as Class K.