Sailfin Molly Breeding Guide (Poecilia latipinna)

Breeding the Sailfin Molly (Poecilia latipinna): a livebearer with internal fertilization, three-to-four-week gestation and broods of 10-140 fry, often in brackish water.

Overview

The Sailfin Molly (Poecilia latipinna) is a euryhaline livebearer of coastal estuaries, lagoons, deltas and swamps, and it readily breeds in brackish water. Fertilization is internal and no parental care is given.

Sexing

Males develop greatly enlarged dorsal fins and colourful caudal fins as secondary sexual characteristics, while females are larger and more plainly coloured. Fertilization is accomplished by the gonopodium, a structure formed from modified fin elements within the male's anal fin.

Conditioning

Depending on conditions, Sailfin Mollies can become reproductive in less than a year and females may give birth several times per year. Females can store sperm long after their relatively short-lived mates have died.

Breeding Setup

This species naturally inhabits brackish coastal waters and tolerates salinities as high as 87 ppt, so hard, alkaline conditions suit it. Dense planting gives the live fry cover from adults, which provide no care.

Spawning Behavior & Trigger

Fertilization is internal via the gonopodium. Although the sex ratio of broods is balanced, adult populations tend to be predominantly female, and males may live less than a year after reaching sexual maturity.

Birth & Fry Care

Gestation is about three to four weeks, varying with temperature. Broods range from 10 to 140 live young depending on the female's size and maturity. The free-swimming fry should be kept among plants or separately, as no parental care is provided.

Common Challenges

Maintaining suitably hard, alkaline (and optionally brackish) water and protecting fry from being eaten are the main considerations.