Endler's Livebearer

The Endler's livebearer (Poecilia wingei) is a diminutive, brilliantly colored relative of the common guppy, discovered in the 1930s and formally described from a small number of coastal lagoons near Cumaná, Venezuela. Males are famous for their iridescent, almost metallic patchwork of orange, blue, green, and black coloration, which varies noticeably between populations from different locales. Females are far less colorful, appearing plain silvery-grey and substantially larger than males. Because Endler's livebearers occupy such a restricted native range, wild populations are considered vulnerable to habitat loss, while captive-bred strains and guppy hybrids are widespread in the aquarium trade. Their small size, hardiness, and vivid colors make them popular for nano aquariums and community tanks alike.

• Size: One of the smallest livebearers in the hobby, with males rarely exceeding 1.2 inches (3 cm)
• Male coloration: Iridescent orange, green, blue, and black patches arranged irregularly along the body, unique to each individual
• Female coloration: Plain silvery-grey with little to no patterning
• Caudal fin: Often pointed or spade-shaped in males, sometimes with a colored edge
• Sexual dimorphism: Extreme; males are small and vivid, females are larger and drab

Look-alikes: Guppies (Poecilia reticulata) are closely related and readily hybridize with Endler's, producing intermediate patterns; pure Endler's strains are maintained by breeders to preserve distinct male color patterns.

Endler's livebearers are native to a very limited area of brackish and freshwater coastal lagoons near Cumaná in Sucre State, Venezuela, including the Laguna de Buena Vista and nearby wetlands. These habitats are typically shallow, warm, and richly vegetated, with mangrove influence creating variable salinity. Because of their restricted range, wild populations are highly sensitive to habitat degradation, pollution, and hybridization with introduced guppies, and some original locales have already lost their fish to development or contamination. In the aquarium hobby, Endler's livebearers thrive in small, warm, well-planted freshwater tanks and tolerate a range of water hardness, though purebred strains are best kept isolated from guppies to prevent crossbreeding.

Endler's livebearers are active, peaceful shoaling fish that spend most of their time in open water and around plants, feeding on small invertebrates, algae, and fine particulate matter. Males display near-constantly, flaring their fins and performing rapid darting displays to court females, competing with one another for female attention through color and movement rather than aggression. As livebearers, females give birth to small broods of 10 to 30 free-swimming fry roughly every 3 to 4 weeks, and can store sperm to produce multiple broods from one mating. Due to their small size and prolific breeding, populations can grow quickly in a suitable aquarium. Fry receive no parental care and are vulnerable to predation by adults.