About the Endler's Livebearer Endler's livebearers (Poecilia wingei) are small, brilliantly colored fish native to the warm, hard-water lagoons of northeastern Venezuela — most famously Laguna de Patos. Despite their tiny size, males display an almost kaleidoscopic range of color patterns, making them a favorite among nano-tank enthusiasts and breeders alike. Hardy, peaceful, and prolific, they're an excellent choice for beginners and experienced hobbyists who want a low-maintenance, visually stunning display fish. There are many strains/varieties of this species available in the aquarium trade. We have broken down some terms/strains that may help you pick the right one! Classes: Endler's Livebearers can be classified based upon what class they are in. It's predominantly based on their lineage and its traceability to having a pure lineage N Class: N Class Endler's Livebearers are the real deal and come from pure Endler bloodlines that have no hybridization and are a wild-type strain of fish. These fish are highly sought after and fetch higher prices due to their genetic value. Often times, breeders may have a certification or paperwork associated with a strain for validity. K Class: K Class Endler's Livebearers often appear like wild-type fish, however there is no documentation or records of the lineage being pure. This category fits many strains of Endler's livebearer that are wild-type strains but with unknown purity. P Class: P Class Endler's Livebearers are almost always hybrids and have guppy (P. reticulata) contributions to their genetic makeup. Some strains of endler would not exist if it were not for genetic contributions from guppies, however if you are aiming to keep a 100% Endler colony, then keep hybrid strains away from pure ones. Strains: Genetic strains are varieties of Endler's Livebearer that are specific colors, patterns, or lineages of fish that make them unique. Some strains include El Tigre, Black Bar, Peacock, Blue Star, Santa Maria, and Campoma #7. Aquarium Setup Tank Size A 10 gallon tank is sufficient for a small colony, though a 20-gallon long is ideal if you plan to keep a larger group or mixed community. This species is active and appreciate horizontal swimming space. Water Parameters Temperature: 72–82°F (22–28°C) pH: 7.0–8.5 Hardness: 10–30 dGH (moderately hard to hard water) Ammonia / Nitrite: 0 ppm Nitrate: <20 ppm Endler's Livebearers thrive in hard, alkaline water that mirrors their native lagoon habitat. Avoid soft or acidic conditions — they will survive but won't thrive or color up as well. Filtration & Flow Use a sponge filter or a hang-on-back filter with a pre-filter sponge over the intake. Endler's livebearers are quite small and their fry are tiny — standard filter intakes can trap or kill them. Keep flow gentle; they prefer calm to moderate water movement. Substrate & Décor A dark substrate (black sand or fine gravel) will make male coloration pop dramatically. Dense plantings of floating plants (frogbit, water lettuce, hornwort) and stem plants (guppy grass, java moss) serve double duty: they provide cover for fry and give females refuge from persistent males. Driftwood and leaf litter are optional but appreciated. Lighting Moderate lighting suits them well. Floating plants help diffuse intense light and reduce stress. Diet & Feeding Endler's livebearers are omnivores and unfussy eaters. Staple: High-quality micro pellets or crushed flake food Protein: Baby brine shrimp, micro worms, daphnia, or frozen cyclops Supplemental: Spirulina flakes or blanched vegetables (zucchini, spinach) Variety improves coloration and reproductive health. Avoid overfeeding — their small bio load can still spike nitrates in a nano tank. Tank Mates Endler's Livebearers are peaceful and best kept with similarly sized, non-aggressive species. Their small size (males reach ~1 inch / 2.5 cm; females ~1.5–1.8 inches / 4 cm) makes them vulnerable to fin-nipping or predatory tank mates. Excellent Companions Corydoradinae Catfish (Corydoras sp.) — peaceful bottom dwellers that won't compete for surface space Otocinclus — algae-eating, gentle, and similarly sized Ember Tetras — small, peaceful Chili Rasboras (Boraras brigittae) — nano-tank staples with similar temperament Nerite Snails Amano Shrimp Avoid Long Finned Bettas- fins may get nipped by male Endler's livebearers Angelfish, cichlids, or any predatory species Tiger barbs or serpae tetras (fin nippers) Large guppies (may hybridize — see Breeding section) Keeping with Guppies Keeping these fish with guppies (Poecilia reticulata) can and will result in hybridization. If you want to maintain pure Endler strains, keep them in a species-only or Endler-only tank. Hybrid offspring are fertile and can quickly muddy a pure line within a few generations. Breeding As their name suggests, Endler's Livebearers are livebearers — females give birth to live, free-swimming fry rather than laying eggs. They are one of the easiest fish to breed in the hobby. Sex Ratio Keep a ratio of at least 2–3 females per male to prevent females from being harassed to exhaustion. Males are relentless in their pursuit. Gestation & Fry Gestation period: 23–28 days Brood size: 5–25 fry per drop, depending on female size and age Fry size: Very small at birth (~4–5 mm) but fully formed and free-swimming immediately Females can store sperm and produce multiple broods from a single mating — a female purchased from a store may already be pregnant. Fry Survival In a heavily planted tank, fry survival is high without any intervention. Floating plants and dense moss provide critical cover. If you want maximum fry survival: Use a breeding box or separate fry to a grow-out tank Feed fry infusoria, powdered fry food, or baby brine shrimp nauplii from day one Perform small, frequent water changes (10–15% every 2–3 days) to support rapid growth Controlling Population This fish breeds prolifically. In a community tank, some fry will be eaten naturally, keeping numbers in check. In a species-only tank, population can grow quickly — plan for rehoming, selling, or adding fry-eating tank mates if needed. Common Health Issues Velvet (Oodinium): Gold dust appearance on skin; treat with copper-based medication and raise temperature slightly Fin rot: Usually caused by poor water quality; improve parameters and treat with antibacterial medication if needed Wasting disease: Gradual weight loss despite eating — often internal parasites; treat with medicated food containing levamisole or fenbendazole Endler's Livebearers are generally robust. Most health issues trace back to water quality — consistent maintenance is your best preventive measure. Quick Reference Difficulty: Beginner Tank size: 10–20 gal recommended Temperature: 72–82°F pH: 7.0–8.5 Adult size: Males ~1 in / Females ~1.5–1.8 in Lifespan: 2–3 years Diet: Omnivore Temperament: Peaceful Breeding: Very easy — livebearer Conclusion Thank you for reading this article on Endler's Livebearers. If you have any questions, please contact us at our email address: scholarlyexotics@gmail.com; we will respond back as soon as possible! Shop for Aquarium Supplies through Scholarly Exotics
