Molly
Scientific name: Poecilia sphenops y variedades
Active fish that adapts well to peaceful community aquariums with good water quality.
Quick facts
- Approximate size6–10 cm
- Average weight4–8 g
- Life expectancy3–5 years (captivity)
- ActivityDiurnal
Basic information
- Habitat: rivers, coastal lagoons, and slightly brackish waters of Central and South America.
- Diet: omnivorous; consumes algae, small invertebrates, and prepared food.
- Sexual dimorphism: males have a gonopodium (modified anal fin) and are usually more stylized.
- Predators: larger fish, aquatic birds, and other shallow water predators.
Life in the wild
How this species lives in its natural environment, with the waters, shelters and resources it needs.
Species overview
The molly is a versatile and robust fish widely used in community aquariums.
Natural habitat
It occupies warm waters with vegetation and access to more open areas for swimming.
Behavior
It forms active groups; males persistently court females.
Special features
Its tolerance to slightly brackish waters makes it interesting for coastal biotopes.
Conservation and threats
As a common species and widely bred in captivity, it is not considered globally threatened.
Curiosities
Striking details about this species that help better understand its biology and role in aquatic ecosystems.
- It can live in fresh or slightly brackish water, depending on the variety and acclimation.
- There are black, dalmata, sailfin mollys and many other forms.
- It is viviparous, like the guppy and platy.
- It tends to reproduce easily in well-maintained aquariums.
Welfare profile
Summary of the most critical points if this species is kept in aquariums, ponds or specialized facilities.
Space and facilitiesMedium
It needs aquariums with space to swim and vegetation where to take refuge.
Water quality and parametersMedium
It requires stable and well-filtered water; tolerates a wide range of parameters if they are stable.
Handling and stressLow
It is quite hardy and tolerates human presence well when conditions are adequate.
Molly in captivity
General information aimed at professional facilities, public aquariums and educational projects. It does not intend to promote capture or impulsive keeping of aquatic fauna.
⚠️ Before keeping fish like this species, it is essential to review local regulations, ensure adequate facilities and minimize impact on wild populations.
Suitable facilities
Ideal for community aquariums with calm and similarly sized companions.
Feeding in responsible centers
The diet includes quality dry food, algae, and live or frozen prey.
Handling and welfare
Dense vegetation helps fry survive and reduces stress in adults.
Ethical message
It is important to avoid releases into natural waters, as they can compete with native species.
Many aquatic species suffer from massive captures, uncontrolled trade and irresponsible releases. The priority should always be to protect rivers, lakes and seas, reduce pollution and consume seafood responsibly.