Breeding the molly
Livebearer; breeds readily, including hybridising with P. latipinna in aquaria.
Step by step
Keep 1 male with 2-3 females. Buy a group of 6 or more young fish and let them pair up on their own.
A 20 gallon (75 L) tank with plenty of plants or spawning mops. Add a pinch of aquarium salt and keep the water hard and slightly alkaline.
Warm, clean, hard water and good food. Males chase females all year.
20-150 young per brood (broods of up to 120 are common); gestation about 4 weeks (FishBase) to around 8 weeks (Seriously Fish).
Fry are free-swimming at birth. Feed crushed flakes, baby brine shrimp and fine powder food. Move fry away from adults, or the adults will eat them.
- Keeping too many males, which stresses the females
- Soft, acidic water
- No hiding places, so the fry get eaten
Male or female
Males are smaller and more colourful and have a gonopodium; females are larger with a normal anal fin.
Can I breed it in my tank?
- Good for a first breeding project.
Day-by-day plan
Typical for livebearers
- 28 days beforePregnancy
A dark 'gravid spot' grows behind the belly. Gestation is usually about 4 weeks.
- Day 0Birth
Fry are born ready to swim. Thick plants or a breeding box keep them safe from adults.
- Day 0First food
Feed crushed flake, baby brine shrimp or microworms 3–5 times a day.
- Day 28Sexing starts
Males start to show color and a pointed anal fin. Separate them if you want to control lines.
- Day 90Adults
Most livebearers are grown and can breed at about 3 months.
A general guide for this breeding type. Days change with temperature and species.
Simulator: guided
A dark 'gravid spot' grows behind the belly. Gestation is usually about 4 weeks.
Simulator: try it yourself
Set up a virtual breeding tank and see what would likely happen.
- The female gave birth.
- With no plants or breeding box, the adults ate most of the fry.
An educational estimate from the breeding rules, not a promise.