The Endler's Livebearer

Very few pet stores carry the Endler's, a beautiful, hardy relative of the guppy. Discovered by the aquarium industry as recently as 1975, these brightly colored, wild-strain fish are exciting and full of personality. Although currently somewhat uncommon for home aquarium displays, the Endler's liverbearer is quickly gaining in popularity.

Endler's livebearers are very similar to guppies, which are very close relatives. In fact, because the two species are able to interbreed and produce fertile offspring. Like the guppy, Endler's livebearers give birth to live young that are free-swimming within a matter of minutes or hours. Both fish varieties will eagerly partake in both interspecies and intraspecies breeding.

Guppies and Endler's livebearers differ in both appearance and behavior. The Endler's livebearer is characterized by its elongated gonopodium (the modified anal fin of male livebearers) and by its distinct color-band in the middle of its body. Endler's livebearers also have a wider variety of colors present on their bodies, and are smaller by comparison, weighing in at about the size of an average dwarf or feeder-guppy.

The Endler's livebearer also exhibits some different behaviors, tending to school with its own kind when individuals of the same species are present. Because of this difference in social behavior, Endler's livebearers and guppies do not generally cross-breed in the wild, even when they are cohabitating in the same natural environments.

The interbreeding of Endler's livebearers are standard guppies is a topic of debate among aquarists and enthusiasts. Endler's livebearers have naturally created a separate species, or at least subspecies, as a result of thousands of years of natural selection. Deliberate cross-breeding between the two livebearer varieties may weaken both gene pools and eliminate the natural adaptions made by each species.

Nevertheless, many breeders feel that it is justifiable to create hybrid strains of guppy and Endler's livebearer, because this strengthens and adds variety to both gene pools to make them suitable for the aquarium industry. Over time, the captive breeding and cross-breeding of the two species may help to eliminate the need for wild-caught individuals, which may protect wild Endler's livebearers.

The Endler's livebearer may gain in popularity in the coming years, or its traits may simply be added to the gene pools of standard guppies. While some aquarists are acting to eliminate the corss-breeding of the two species, it will most likely continue, even if only in captive, controlled populations.