Molly
Poecilia sphenops · Poeciliidae
Also known as Sailfin molly, Black molly
Beginner
Large livebearer that wants hard, warm, mineral-rich water — often kept slightly salted.
In short: A molly needs at least 90 L (24 US gal), water at 24–28 °C (75–82 °F) and pH 7.5–8.5. It is peaceful, best kept in groups of 3 or more, and rated beginner to keep.
Updated
- Minimum tank
- 90 L (24 US gal)
- Temperature
- 24–28 °C (75–82 °F)
- pH
- 7.5–8.5
- Adult size
- 10 cm (3.9 in)
- Group size
- 3+
Care requirements
- Minimum tank volume
- 90 L (24 US gal)
- Temperature
- 24–28 °C (75–82 °F)
- pH
- 7.5–8.5
- Hardness
- 12–30 dGH
- Lifespan
- 3–5 years
- Diet
- Herbivore-leaning omnivore — algae wafers, vegetable flake, greens.
- Care level
- Beginner
Origin & habitat
- Native region
- Mexico to Colombia, coastal waters
- Water type
- Freshwater
- Biotope
- Hard coastal streams and estuaries
- Natural conditions
- Very hard, alkaline, warm water, often brackish.
Behaviour & stocking
- Temperament
- Peaceful
- Minimum group
- 3 fish
- Swims
- All levels
- Good tank mates
- PlatySwordtailBristlenose pleco
- Avoid
- Soft-water speciesBetta
Breeding & difficulty
- Breeding difficulty
- Beginner
- Sexing
- Males have a gonopodium; sailfin males grow a huge dorsal.
- Notes
- Livebearer with large broods; fry need space and greens.
- Common ailments
- Molly shimmiesColumnarisIch
Will it fit your tank?
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- Check the molly with your other fish in the stocking checker
