Endler Grading


Grade refers to standards individual fish can be compared to as they relate to a ”prime” or “perfect” specimen within a given Strain. The Endler Shop developed these grading standards while selecting "Best in Breed" males to breed future generations. These best in breed male fish exemplify this "perfect" specimen, i.e. color, pattern, finnage, balance, symmetry, and size. Of course each fish is unique and has its own charms, but when compared to a "Best in Breed" Grade A fish, they stand out. Grading standards are outlined in each Strain section below. Also, see the images on the right for examples. A final note: when purchasing “A” grade males, these Endlers may not have every ideal trait. However, they will have a majority of them which puts them into the A grade status.

Grade: A / Class: N (Pure Strain) / Strain: Black Bar


Black Bar Strain Grading


The Black Bar Endler Strain has a prominent "Black Bar" on both flanks, creating a striking contrast with the other bright adjacent colors. Alongside the Black Bar, other prominent colors on the body usually include red, orange, & yellow (& occasionally green). Also, sometimes specks of blue, green & purple can be seen as well. Additionally, there is often a light blue patch under the dorsal fin and the tail usually displays a red / orange "sword and a half" outlined in black. The dorsal fin may be clear or occasionally display orange, red and black. Black Bar Grading Standards:



Peacock Strain Grading


The Peacock Endler strain has a prominent black “Peacock” like spot on its tail which is a striking focal point that offsets the other bright colors on its torso. The top portion of both flanks are distinguished by a red / orange stripe (sometimes broken) and a black spot(s) below the stripe. Alongside the red / orange stripe and black spot(s), other prominent colors on the body often include yellow & green. Also, but rarely, specks of blue, green & purple can be seen as well. Additionally, the tail usually displays a red / orange bottom and or top “sword” outlined in black. The dorsal fin may be clear or occasionally display orange, red and black. Peacock Grading Standards: 



Endler Genetics


Endlers are similar to and very closely related to the guppy. In fact, their genetics are so similar that there is debate whether they are officially the same species, a subspecies or simply a breed of guppy. If for no other reason, their own scientific species name of Poecilia wingei is used to signify this difference for conservation purposes.


Broadly speaking, most Endler male colors & patterns are passed along the Y (male) chromosome. This means colors & patterns of male offspring come primarily from the male parent, usually resulting in fathers and sons closely resembling each other. This hereditary process encompasses complicated biological systems, so there are always exceptions. For a more detailed genetic view, check out this Endler / Guppy Genetics Primer.


Additional Endler genetic factoids:



Observations: N vs P Class


By definition, the difference between N Class Pure Strain and P Class fish should only be documentation; in other words, solid proof that the fish have not been crossbred with "regular" guppies. However, almost every time I’ve come across P Class fish, I have concluded that there has been at least some measure of hybridization. There are several distinct differences when compared to N Class Pure Strain ELBs. These differences include: behavior, color intensity, color patterns, quantity of colors and body shape / morphology. So, although at a glance, the two classes are pretty similar, I'd bet that the vast majority of P Class fish in the real world (every pet store I've encountered Endlers in) have some measure of hybridization. These are the specific differences I’ve noticed when compared to P Class fish:


N Class Pure Strain Males:


N Class Pure Strain Females:


My first impressions of N Class Pure Strain Endlers, after keeping P Class fish for some time, were "These fish seem wild!” There was something I could not quite put my finger on, but the overall impression was definitely distinct and fascinating. Undoubtedly, this impression was a result of all the differences noted above, but which I had not yet outlined. A fitting analogy is the differences we think of when comparing wolves and dogs. In essence, the P Class fish physical and behavioral traits have “softened” or become more dog/puppy like as compared to their wilder N Class Pure Strain cousins.


Of course, it's important to keep N Class fish genetically pure to ensure their continued existence. However, P Class fish are charming in their own right as well. In fact, some of their “dog / puppy" like qualities make them great to fish to keep.



Documentation of N Class


Where do N Class Pure Strain Endlers come from?

Very few, if any descendants of the Endlers collected by Dr. Endler in 1975 remain due to hybridization and inbreeding. However, after speaking with Dr. Endler, a wild fish collector gathered fresh wild Endler stock from their native lagoons in Venezuela. Beginning in the late 1990s and continuing into the next decade, these expeditions collected hundreds of wild Endlers from their native habitat and expanded the captive breeding stock. Although not yet taken up into the IUCN Red List of endangered species, Endlers are either no longer found in the wild or are extremely rare because of habitat destruction and pollution. In essence, Endlers are likely already extinct in the wild, so the stock from these collections encompass the only known N Class Pure Strain population in today’s hobby. In hindsight, the value of these expeditions cannot be overstated since there would not be any Endler populations left in existence without those collections. The stock from these collections was provided to the Endlers Livebearers Association of America (ELAA).


Which fish are considered N Class Pure Strain & how is this documented?

Only fish that are directly descended from the original ELAA stock and which are verified by documentation throughout their entire line of descent are deemed to be N Class Pure Strain fish. This documentation is provided by breeder Registries. My listing in the ELAA N Class Pure Strain Registry (screen captures to the right-highlighted in yellow) validates The Endler Shop’s fish as Pure Strain, by documenting line of descent back to the original stock.


How does The Endler Shop document Pure Strain Fish for customers?

The Endler Shop also maintains an N Class Pure Strain Registry of customers who purchase N Class fish. Since our fish are registered to the original ELAA stock, the listings in our Pure Strain Registry completes the documentation, tracing the entire line of descent back to the original ELAA stock. This validates our customers’ fish pedigree as Pure Strain. Customers with eligible N Class Endler orders (8 fish mixed male & female of a strain) may request inclusion in our Registry during purchase.

Grade: A / Class: N (Pure Strain) / Strain: Black Bar


Grade: A / Class: P (Not Pure Strain) / Strain: Black Bar


Grade: C / Class: P (Not Pure Strain) / Strain: Black Bar


Grade: C / Class: N (Pure Strain) / Strain: Black Bar


Grade: B / Class: N (Pure Strain) / Strain: Peacock


Grade: A / Class: N (Pure Strain) / Strain: Peacock


Grade: A / Class: N (Pure Strain) / Strain: Peacock


Grade: B / Class: N (Pure Strain) / Strain: Peacock