Will I receive a male or female?

This is sold as a mixed-sex fish — you may receive either a male or female. At 3 cm, sexing is becoming possible: males have a pointed anal fin (gonopodium) while females have a fan-shaped anal fin. If you need a specific sex, please contact us before ordering.

Is the balloon shape harmful to the fish?

No. The balloon body shape is a stable genetic trait that has been bred in mollies for decades. Balloon mollies are active, eat well, breed readily, and live as long as standard mollies. They are slightly slower swimmers, which is why we recommend keeping them with other peaceful fish.

How big will it grow?

These are sold at approximately 3 cm as juveniles. Adults reach 5–6 cm — slightly smaller than standard black mollies due to the compressed body shape. The balloon shape becomes more pronounced as the fish matures.

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Poecilia sphenops

Black Balloon Molly – Mixed Male & Female

Name: Black Balloon Molly – Mixed Male & Female
Brand: Tropical Fish Co
SKU: f86f8145-1a12-4b87-91c1-82ad8f6b86be
Price: 4.84 GBP
Availability: InStock

Beginner Friendly

Peaceful

£4.84In Stock

Black Balloon Molly (Poecilia sphenops) – a striking livebearer with a distinctive rounded balloon body shape in jet-black colouration. Sold individually as a mixed-sex fish at approximately 3 cm. The compact, rounded body and velvety black colour make this a popular and eye-catching community fish.

Balloon MollyBeginner FishBlack MollyLivebearerMolly

Care at a Glance

Scientific Name

Poecilia sphenops

Adult Size

6 cm

Lifespan

5 years

Care Level

Easy

Temperament

Peaceful

Temperature

24–28°C

pH Range

7–8.5

Hardness

10–25 dGH

Minimum Tank

60L

Diet

Flakes, pellets, frozen foods, algae, spirulina

Premium Quality

Healthy, vibrant fish from trusted suppliers

Expert Care

Detailed care guides and support

Live Arrival Guarantee

Your fish arrives healthy or we'll replace it

Acclimated

Properly quarantined and ready for your tank

Quick Care Guide

Temperature

24–28°C

pH Range

7–8.5

Minimum Tank

60L

Adult Size

6 cm

Lifespan

5 years

Care Level

Easy

Temperament

Peaceful

Diet

Flakes, pellets, frozen foods, algae, spirulina

Water Hardness

10–25 dGH

Tank Region

Middle

Water Parameters

Maintain these water conditions for optimal health and vibrant colors

Temperature

24–28°C

24°CIdeal Range28°C

pH Level

7–8.5

7Ideal Range8.5

Water Hardness

10–25 dGH

10 dGHIdeal Range25 dGH

Why Choose This Fish?

The Black Balloon Molly (Poecilia sphenops) combines two of the most popular molly traits — the deep velvety black colouration and the distinctive rounded balloon body shape. The result is a compact, charming fish with a unique silhouette that stands out in any community tank. Sold individually at approximately 3 cm, these juveniles will grow to 5–6 cm and develop their full balloon shape as they mature.

Care at a Glance

Scientific Name	Poecilia sphenops
Adult Size	5–6 cm
Temperature	24–28 °C
pH Range	7.0–8.5
Hardness	10–25 dGH
Minimum Tank	60 litres
Diet	Flakes, pellets, frozen foods, algae, spirulina
Temperament	Peaceful
Lifespan	3–5 years
Care Level	Easy

The Balloon Body Shape

Balloon mollies have a naturally shortened spine that creates their distinctive rounded appearance. This is a stable genetic trait, not a deformity — balloon mollies are active, healthy fish that breed readily. Their compact shape means they are slightly slower swimmers than standard mollies, which actually makes them easier to observe and enjoy.

Jet-Black Beauty

The black colouration in mollies is one of the most intense blacks found in freshwater fish. Under good conditions with a balanced diet including spirulina and algae, the velvet-black colour deepens with age. A dark substrate and planted background make these fish truly striking.

Tank Mates

Peaceful with all community fish. Compatible with other mollies, platies, guppies, and corydoras. Browse our molly collection including Silver Sailfin Mollies, Balloon Sailfin Mollies, and Black Sailfin Balloon Mollies.