Marty has been a tropical fish hobbyist most of his life. He has kept Endlers since February of 2013.
Is the Endler Livebearer Really a Guppy?
Often called Endlers guppies, Endlers Livebearers closely resemble guppies (Poecilia reticulata); in fact, for several years there was quite a bit of controversy over the species.
Even today, many still believed that the Endlers Livebearers are just another variety of guppy.
Genetic Studies Classifying Endlers as Poecilia wingei
Studies concerning whether Endlers are guppies or a distinct and separate species continued for many years.
In 2009, Manfred. K. Meyer and Manfred. Schartl published their findings based on molecular data showing that although this species closely resemble guppies, they are a distinct species of their own, and they have been classified as Poecilia wingei, not Poecilia reticulata or Poecilia Obscura.
What Makes Endlers Different From Guppies
Those who have had the opportunity to keep pure N class Endlers usually report that not only do Endlers have a different body shape and color patterns but also exhibit different behavioral patterns.
Endlers are very active, occupying every level of the tank. Most hobbyists find them to be a pleasure to watch.
Once in a while, a male who is showing off to the females will skillfully swim backward in an effort to attract her attention.
Physical Differences Between Guppies and Endlers
Although at first glance Endlers and wild-type or feeder guppies look similar, there are some distinct differences between them.
Male Endlers have more intense and brighter colors than guppies. The green or orange colors, often metallic in appearance, are especially unique.
Many pure strains of Endlers have small clear dorsal fins. This, however, is not an indication of purity as there are several strains that have colorful dorsal fins. Color in the dorsal fin, as with other Endler traits, can be manipulated using selective breeding techniques.
Some hobbyists believe that white dorsal fins are the sign that the Endler is a hybrid. This is not necessarily true. The pure Lime Green Endler has a white or very light blue dorsal fin.
Fin Size and Length
Fin size and length is another difference between Endlers and guppies.
Guppies often have large flowing fins while Endlers usually have much smaller fins.
Long flowing fins in Endlers are a good indicator that the Endler has been hybridized with a guppy.
Endlers often have a small sword on their caudal (tail) fin. This small sword is often only a coloration that seldom extends much past the caudal fin.
Occasionally, Endlers can develop a very long sword on their caudal fin. Although the fin may grow long, it stays thin. Thicker flowing swords are another indication of hybridization.
Body Shape and Size
Endlers have a thinner body shape than guppies. This is especially apparent where the body meets the tail of the Endler.
Male Endlers are usually smaller than guppies; however, female Endlers can grow as large as female guppies.
The gonopodium is the male sexual organ used to impregnate a female Endler. Endlers have one small hook on their gonopodium while guppies have several hooks.
Do Endlers Eat Their Fry?
There is some information available from breeders saying that Endlers will not eat their fry. Some even think that it’s a way to tell if it’s pure or not.
This is not 100% true. Endler males and young females will seldom eat the fry.
However, large female Endlers have no problem eating the young fry and may even develop an appetite for them.
How to Prevent This
Hobbyists that keep livebearers will often keep a large number of plants and decorations in their aquarium.
This technique also works well when breeding Endlers Livebearers. Not only do the plants and decorations provide a place for the fry to hide from larger Endlers, but they also provide a place for the females to get some rest from the relentless males.
Is My Endler Pure?
Even if an Endler has the shape, size, and coloration, it doesn't mean that it's pure.
The only way to truly be sure your Endler is pure is to do genetic testing. Most people don't have that option. To give you the best chance of getting pure Endlers you should find a breeder that keeps good records and can show you where his Endlers have come from, all the way back to their collection in Venezuela.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2021 Marty Andersen