Dalmatian Sailfin Molly (Poecilia latipinna)

The Dalmatian Sailfin Molly (Poecilia latipinna) is a white molly splashed with black speckles, built on the bigger sailfin body. Mature males raise a tall, wide dorsal fin like a sail when they display, and that sail is the reason to pick a sailfin over a regular molly. It is a peaceful, active livebearer and a good beginner fish, as long as it gets hard water and room to grow. Browse the rest of our freshwater fish and supplies.

Sailfin or Lyretail?

Both are mollies, but they are built differently. A sailfin is the larger fish, with the tall dorsal on mature males and a rounded tail. A lyretail has long points on the top and bottom of the tail instead. The sail is not fully grown at the size we sell: it develops as a male matures, and it grows best in warm, hard water with space to swim. Cramped or soft-water tanks are why some sailfins never put up a real sail.

Care Guide

• Tank size: starts in a 30 gallon, plan on 40 or more as it grows. Sailfins reach about 5 inches and need swimming length, so a long tank beats a tall one.
• Water: 72 to 82°F, pH 7.5 to 8.5, and hard water. Hardness matters more than anything else with mollies: soft, acidic water is the most common reason they decline.
• Diet: omnivore with a real need for plant matter. Feed a quality flake plus spirulina or algae foods, and they will also graze soft algae in the tank.
• Temperament: peaceful with other fish. Males chase females constantly, so if you keep males, give each one several females to spread out the attention.
• Aquascape: open swimming space with some plants or decor for cover. Mollies are messy eaters with a high bioload, so plan on good filtration and regular water changes.
• Watch for: clamped fins and shimmying, a side to side wobble in place. It almost always means the water is too soft, too cold, or dirty.

Specifications

Compatibility

Sailfin mollies do well with other peaceful fish that like the same hard, alkaline water: Red Wag Platies, Calico Showa Swordtails, other mollies, and Bristlenose Plecos for the bottom. Racetrack Nerite Snails are a good cleanup crew alongside them.

Skip fin nippers like tiger barbs and serpae tetras, which go after the tall dorsal. Avoid soft water specialists such as many wild tetras and dwarf cichlids, since the water mollies need is not the water those fish need. Very small fish and shrimp fry can get eaten.

Recommended Foods & Supplies

• Xtreme Community Crave Krill/Spirulina Flakes as the daily staple flake
• Xtreme Spirulina Flakes to keep plant matter in the diet
• Hikari Mini Algae Wafers or Repashy Soilent Green as a vegetable treat a few times a week
• Seachem Prime for every water change
• Fritz GH Test Kit to check your hardness, then Seachem Replenish or Seachem Alkaline Buffer if your water runs soft

FAQ

Why doesn't my sailfin have a big sail?
The sail grows as a male matures, and females never grow one. A young male can take months to raise a full sail, and he needs warm, hard water, good food and room to swim. Cramped tanks and soft water are the usual reasons it never shows.

Will the spots stay the same?
Not exactly. Dalmatian speckling often shifts as the fish grows, with spots spreading, fading or darkening over time. Each fish is a little different, and the pattern you see at pickup is a starting point.

Do mollies need salt?
No. Mollies can live in brackish water, but they do not need salt in a freshwater tank. What they do need is hard, alkaline water. Test your GH and raise it if your tap water is soft.

Why is my molly shimmying?
A side to side wobble in place is the classic molly stress sign. Check temperature, hardness, pH and ammonia, and do a water change. Fixing soft or dirty water usually clears it up.

How big does a Dalmatian Sailfin Molly get?
Up to about 5 inches, bigger than most people expect from a molly. That is why we suggest starting in a 30 gallon and planning on 40 or more as it grows.