Poecilia latipinna
Big livebearer with a dramatic dorsal sail (males). Demands hard alkaline water, happiest with a teaspoon of marine salt per 5 L, though it'll do fine in just hard SA tap. Don't keep with soft-water tetras; the parameter mismatch breaks both. Males don't appreciate each other in confined tanks.
Sailfin Molly (Poecilia latipinna) reaches 8–12 cm as an adult and needs a minimum tank of 120 L. Native to Southeastern USA & Mexico, some brackish populations, it lives in the mid to top water column with a peaceful (males spar) temperament. Aim for 22–28 °C, pH 7.5–8.5, and 15–30 dGH hardness. Lifespan is 3–5 years with good care. Keep sailfin molly in groups of 4+, no (live in groups) schoolers need numbers to display natural behaviour. Diet: omnivore (heavy plant matter), Vegetable-forward, spirulina flake, blanched courgette, peas. Will graze algae. Daily. Plant-safe: Mostly (may nip soft leaves). Shrimp-safe: Adults only (will eat shrimplets).
Care at a glance
Big livebearer with a dramatic dorsal sail (males). Demands hard alkaline water, happiest with a teaspoon of marine salt per 5 L, though it'll do fine in just hard SA tap. Don't keep with soft-water tetras; the parameter mismatch breaks both. Males don't appreciate each other in confined tanks.
By Mike ElmiraUpdated 1 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether sailfin molly fits in your tank.
Mid to Top
No
Small group of 4+
Poeciliidae
Omnivore (heavy plant matter)
Vegetable-forward, spirulina flake, blanched courgette, peas. Will graze algae. Daily.
3–5 yrs
Easy
Brackish coastal marshes of the Gulf of Mexico
Southeastern USA & Mexico, some brackish populations
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Sailfin Molly (Poecilia latipinna) needs a minimum tank of 120 L. They live in the mid to top water column and should be kept in groups of 4+, so a longer footprint matters more than depth.
Target 22–28 °C, pH 7.5–8.5, and 15–30 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Adults only (will eat shrimplets). Plant safety: Mostly (may nip soft leaves).
Sailfin Molly are omnivore (heavy plant matter). Vegetable-forward, spirulina flake, blanched courgette, peas. Will graze algae. Daily.
On Fin & Stem's 1–5 difficulty scale this species rates 2/5. Forgiving, beginner-friendly once the tank is cycled. Breeding difficulty: easy.
Typical lifespan in a well-maintained tank is 3–5 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
