Endler's Livebearer

Looks how to spot one

Small scaled livebearer (poeciliid) with strong difference between the sexes

A very small, slender livebearer. Males are little jewels, splashed with metallic greens, oranges and neon tones and often marked with bold black patches and bars that darken further when they court. Females are noticeably bigger and rounder, with a plain silvery-tan body. Like their guppy cousins, males carry a modified anal fin used for internal fertilisation.1235

Personality what they are like

Lively, curious and mostly peaceful. Males spend much of their day showing off to females, so it helps to keep more females than males. Females can be a little bossy with each other, and a group will settle into its own pecking order. Their small size makes them best suited to calm tanks with other small, gentle fish.243

Daily activity how busy a day looks

An active swimmer that patrols the upper and middle water all day. Give open swimming space plus some plants so females can take a break from courting males.43

Grooming and care the hands-on bits

Undemanding. Keep water clean with regular partial water changes and feed small amounts of varied food. Because they breed so readily, plan ahead for the extra fish, either with a larger tank or by keeping single-sex groups.32

Home where they are happiest

A small colony can live in a tank of about 45 x 30 x 30 cm (roughly 40 litres); hobby guides suggest 20 to 75 litres as a starting point, and more room as the colony grows. Temperature roughly 18 to 30 C (24 to 30 C is the classic warm range, though many keep them unheated at room temperature). pH about 6.5 to 8.5, with moderately hard water (around 15 to 35 dGH) suiting them best long term. Plants and floating cover are appreciated.234

Food basics what goes in the bowl

An omnivore. In the wild it picks at tiny bottom-living creatures and organic debris. In the aquarium it takes small flakes, pellets and gel food, plus treats like daphnia, brine shrimp and bloodworm, and it should also get some plant matter such as algae or spirulina.234

Company who they like around

Best kept as a group, ideally with two or three females for every male. Good companions are other small, peaceful fish such as dwarf corydoras, small rainbowfish and gentle tetras. Keep them apart from common guppies, because the two species readily cross and pure Endler lines are lost.23

The story where it all began

The fish was first collected in 1937 by the American fish collector Franklyn F. Bond in north-eastern Venezuela, but it went largely unnoticed for decades. In 1975 the biologist John Endler, who studied guppy evolution, found it again at Laguna de Patos near Cumaná. That lagoon had once been a brackish lake cut off from the sea by a sandbar and had slowly turned fresh, with very warm, hard, algae-green water. Endler's fish soon spread through the aquarium hobby under his name. Scientists debated for years whether it was simply a guppy variety, until Poeser, Kempkes and Isbrücker described it as a species, Poecilia wingei, in 2005, naming it after the Danish geneticist Øjvind Winge. Later DNA studies supported it as a separate species. The original lagoon population is now thought to be gone, and the fish lives on mainly through dedicated hobby breeders who keep wild-type lines pure. It is listed as Endangered by the IUCN.215

Recognised by the official bits

IUCN Red List

Assessed as Endangered (EN), March 20211

Scientific description

Formally described as Poecilia (Acanthophacelus) wingei by Poeser, Kempkes and Isbrücker in 2005 (Contributions to Zoology); molecular work supports it as a valid species distinct from the guppy2