Sailfin Molly

Also known as the Yucatan Molly or Giant Sailfin Molly

The Sailfin Molly is a hardy, attractive livebearer that showcases a spectacular, oversized dorsal fin and adaptable nature that makes it suitable for both freshwater and brackish aquariums. Native to coastal regions of the southeastern United States, Mexico, and Central America, this peaceful species features a robust body with variable coloration and the males’ signature sail-like dorsal fin that they display during courtship. Their tolerance for varying salinity levels, easy care requirements, and prolific breeding make them an excellent choice for beginners and experienced aquarists alike seeking an active, personable fish for community setups.

Key Features

• Scientific Name: Poecilia latipinna
• Common Names: Sailfin Molly, Yucatan Molly, Giant Sailfin Molly
• Adult Size: Males 4–5 inches (10–13 cm); Females 5–6 inches (13–15 cm)
• Lifespan: 3–5 years with proper care
• Temperament: Peaceful and social; males may display to each other but rarely aggressive
• Tank Compatibility: Community-friendly; thrives with other peaceful species
• Minimum Tank Size: 30 gallons minimum (55+ gallons for groups)
• Experience Level: Beginner to intermediate – hardy and forgiving

Habitat & Tank Requirements

Natural Habitat: Found in coastal freshwater streams, brackish estuaries, salt marshes, and mangrove swamps. Tolerates wide salinity ranges from pure freshwater to full marine conditions.

Tank Environment:

• Open swimming areas with moderate planting
• Hardy plants like Java fern, Anubias, or brackish-tolerant species
• Smooth substrate (sand or fine gravel preferred)
• Driftwood and rocks for shelter and visual interest
• Moderate water flow
• Good surface agitation for oxygen exchange

Water Parameters:

• Temperature: 72–82°F (22–28°C)
• Salinity: 0–1.015 specific gravity (freshwater to brackish; salt optional but beneficial)
• pH: 7.5–8.5 (alkaline water preferred)
• Ammonia/Nitrite: 0 ppm
• Nitrate: <20 ppm
• Hardness: 15–30 dGH (hard water essential)

Diet & Feeding

Sailfin Mollies are omnivores with a strong preference for vegetable matter and require a varied diet for optimal health and coloration.

Recommended Foods:

• Vegetable Matter: Spirulina flakes, blanched vegetables (zucchini, spinach, peas), algae wafers (primary diet)
• Protein Foods: High-quality tropical flakes, frozen brine shrimp, frozen bloodworms, daphnia (supplementary)
• Natural Grazing: Algae growing on tank surfaces (encourage growth)
• Prepared Foods: Herbivore pellets, color-enhancing formulas

Feeding Schedule:

• Feed 1–2 times daily
• Offer small amounts that can be consumed in 2–3 minutes
• Provide vegetable-based foods daily
• Supplement with protein 2–3 times weekly
• Allow grazing on naturally occurring algae

Behavior & Compatibility

Temperament:

• Peaceful and active throughout the day
• Males display elaborate fin-spreading courtship behavior
• Social species that thrives in groups (3+ recommended)
• Occasional mild chasing between males, rarely harmful
• Very active swimmers that occupy all tank levels

Tank Mates:

• Compatible with: Platies, swordtails, guppies, peaceful tetras, Corydoras catfish, peaceful gouramis, Otocinclus
• Caution with: Fin-nippers (may target males’ large dorsal fins), very small fry (adults may eat them)
• Avoid: Aggressive cichlids, large predatory fish, fish requiring soft, acidic water

Breeding Behavior:

• Livebearers that give birth to free-swimming fry
• Extremely prolific breeders (20–100+ fry per brood)
• Females store sperm and can produce multiple broods
• Provide dense planting or breeding box to protect fry
• Adults may eat their own young without cover

Color Varieties

Wild Type:

• Silver-gray body with rows of spots
• Iridescent blue-green highlights
• Orange or yellow edging on fins

Common Varieties:

• Black (Midnight): Solid black coloration
• Gold Dust: Yellow-gold with dark speckles
• Dalmatian: White with black spots
• Marble: Mixed black and white patterns
• Albino: Pale yellow-orange with red eyes

Why Choose a Sailfin Molly?

Sailfin Mollies are ideal for aquarists seeking a beautiful, hardy species that adapts well to various water conditions and thrives in community settings. Their peaceful nature, striking appearance (especially males in breeding display), and active personality make them engaging aquarium residents. The species’ tolerance for brackish water makes them excellent for transitional setups or as companions for other brackish-tolerant fish. With proper care, these livebearers provide years of enjoyment and, for those interested, the rewarding experience of breeding and raising fry in the home aquarium.

Note: Adding aquarium salt (1–2 tablespoons per 5 gallons) or maintaining low brackish conditions often improves health, reduces disease susceptibility, and enhances coloration, though they adapt well to pure freshwater when parameters are kept alkaline and hard.