Yucatan Sailfin Molly Care Guide
Poecilia velifera is the largest sailfin molly, a brackish-tolerant livebearer endemic to the Yucatan Peninsula that needs hard, alkaline water.
Compiled by Aquairi from published sources · Published · Updated
Overview
Poecilia velifera is a livebearing fish of the family Poeciliidae, described by Regan in 1914. It is the largest of the sailfin mollies, and mature males develop a tall, sail-like dorsal fin carrying 15 to 21 rays. The body is olive-green with brown longitudinal stripes and iridescent spots, with males showing the most elaborate coloration.
Taxonomy
- Family: Poeciliidae
- Genus: Poecilia
- Scientific name: Poecilia velifera
- Author: Regan, 1914
Habitat
The species is native to the Yucatan Peninsula of Mexico, including the Yucatan-Quintana Roo and lower Usumacinta-Laguna de Terminos systems. It inhabits coastal lagoons, estuaries, salt marshes, mangrove swamps and freshwater cenotes, usually in shallow water under one metre deep. It tolerates a broad range of salinities, from fresh to salt water, but does best in alkaline, hard water.
Tank requirements
- Minimum tank volume: 200 L
- Temperature: 24-28 °C (75-82 °F)
- pH: 7.5-8.5
- GH: 15-30 °dGH
- Lifespan: 3-5 years
- Adult size: 10-18 cm (FishBase max ~15 cm)
Diet
Poecilia velifera is an omnivore. In the wild it feeds largely on filamentous algae and diatoms, along with small crustaceans and insects. In the aquarium it accepts live, frozen and dried foods, and a significant portion of vegetable matter such as blanched spinach should be included to match its naturally herbivore-leaning diet.
Compatibility
The species is peaceful in a community setting but must be kept only with other fish that tolerate hard, alkaline water, such as swordtails and platies. Seriously Fish notes it should not be housed with other molly species because of the risk of crossbreeding. Males pursue females vigorously, so a ratio of about two females per male is recommended.
Breeding
The species is a livebearer that produces fully formed young. Gestation lasts roughly four to eight weeks at 25-30 °C; brood sizes typically range from about 20 to 60 fry, though much larger broods are recorded. The relatively large fry will accept brine shrimp nauplii and powdered foods from birth.
Conservation status
FishBase and the IUCN Red List assess Poecilia velifera as Vulnerable (assessed March 2018), reflecting habitat loss from urbanisation and coastal development across its restricted Yucatan range. It is protected under Mexican law.
Yucatan Sailfin Molly Breeding Guide
Overview
Poecilia velifera, the Yucatan or giant sailfin molly, is the largest sailfin molly, native to the Yucatan Peninsula of Mexico where it occurs in coastal lagoons, estuaries and salt marshes as well as freshwater. It tolerates a broad range of salinities but is most successful in freshwater, and is listed as Vulnerable by the IUCN. Most aquarium stock is captive-bred, and many fish sold as P. velifera are P. latipinna x P. velifera hybrids. It is a livebearer.
Sexing
Males are somewhat larger than females, reaching 7.2-9.25 cm total length versus 4.5-7.2 cm in females. Mature males develop a tall sail-like dorsal fin bearing 15 to 21 rays, taller than that of any other molly, and carry a gonopodium. Males are polymorphic in size and colour, with large ornamented, intermediate ornamented and cryptic intermediate classes.
Conditioning
The species occurs at 25-30 °C in the wild and prefers still or slow-moving water; as a sailfin molly it requires hard alkaline water and does poorly in soft, acidic conditions. It is primarily herbivorous, favouring filamentous algae and diatoms but also taking crustaceans and insects, so conditioning diets should be rich in vegetable matter.
Mating & Gestation
Fertilization is internal via the gonopodium. Gestation is approximately 28 to 40 days at 25-30 °C. In the wild breeding extends from late February to late July. Brood size varies with female size: about 47 fry at 6 cm total length, averaging around 77, ranging from as few as 10 to up to 120 young.
Birth & Fry Care
Newborns are about 9-11 mm total length regardless of mother size, and are large enough to take small live and prepared foods immediately. A spacious, well-planted setup suits this large species; a 110-litre aquarium may house only a pair or trio. As with other mollies, dense planting or separating the gravid female protects fry from predation.
Common Challenges
Adult males grow large and need substantial tank volume, and full sail development depends on good water quality and adequate vegetable matter. Soft or acidic water is harmful. Because much commercial stock is hybridized, fish intended for breeding true P. velifera should be sourced carefully.