Short finned molly - Poecilia sphenops
Scientific name: Poecilia sphenops
Common name: Short finned molly
Family: Poeciliidae
Usual size in fish tanks: 12 - 15 cm (4.72 - 5.91 inch)
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Recommended pH range for the species: 7 - 8.5
Recommended water hardness (dGH): 12 - 18°N (214.29 - 321.43ppm)
0°C 32°F30°C 86°F
Recommended temperature: 21 - 26 °C (69.8 - 78.8°F)
The way how these fish reproduce: Pseudo-Livebearer
Where the species comes from: Central America
Temperament to its own species: peaceful
Temperament toward other fish species: peaceful
Usual place in the tank: Top levels
Feeding
The Short-finned Molly (Poecilia sphenops) is an omnivorous species with a strong preference for plant-based foods. In captivity, a balanced diet of quality vegetable flakes, granules, and spirulina-based foods is essential. They also enjoy occasional protein-rich treats like bloodworms, brine shrimp, and daphnia, but these should be offered sparingly. Fresh vegetables, such as blanched spinach, zucchini, or peas, are excellent additions to their diet, supporting healthy digestion and vibrant coloration. Feeding should be done in small portions twice daily to prevent overfeeding and maintain water quality. Be sure to remove any uneaten food within 5 minutes to prevent it from polluting the water.
Sexing
Sexing Short-finned Mollies is relatively straightforward. Mature females tend to be larger than males and have a more rounded belly, especially when pregnant. Males are typically smaller, with a more slender body shape, and they possess a gonopodium, a modified anal fin used for reproduction. Observing these traits can help identify the gender of your Mollies for breeding or general care purposes.
Breeding
Breeding Short-finned Mollies is quite easy and follows a similar process to other livebearers, like Guppies. They are classified as pseudo-livebearers, which means the female retains the eggs within her body until they hatch, giving birth to free-swimming fry. Simply place a male and female in the same tank, and nature will take its course. The male may display courtship behavior, chasing the female and curling his body around her as part of the mating dance. After a gestation period of about 4-6 weeks, the female will give birth to a batch of fry, numbering between 20-50. To protect the fry, a well-planted tank or a breeding box is recommended, as adults may eat the young fish. Fry should be fed on crushed flakes or specially formulated fry food to support growth and development.
Lifespan
With proper care, Poecilia sphenops typically lives up to 3 years in captivity. Consistent water quality, a varied diet, and a stress-free environment can support a longer, healthier lifespan. With optimal conditions, some Mollies have been reported to live up to 5 years.
Additional Information
The Short-finned Molly, also commonly known as the Black Molly or simply Molly, is a peaceful and hardy fish well-suited for community tanks. They are adaptable to both freshwater and slightly brackish water, showing improved health and coloration in lightly salted aquariums (about 1 teaspoon of salt per 5 gallons). Mollies are particularly sensitive to poor water conditions, so maintaining stable water parameters is key to their health. Regular water changes and a high-quality filtration system are recommended for these active fish. They thrive in tanks with moderate water flow and appreciate a well-planted environment where they can forage and explore.
Questions and Answers
This question was moved from aqua-fish.net/answers on March 24, 2011, due to merging content.
How can I tell if my mollies are mating?
Answer: When mollies are ready to mate, the male will often chase the female around the tank, showing increased interest and occasionally a bit of aggression. Once the female is receptive, the two will engage in a "mating dance," where they curl their bodies around each other briefly. This behavior is typical of courtship in Mollies.
Origin
The Short-finned Molly (Poecilia sphenops) is native to Central and South America, specifically in regions spanning from Mexico to Colombia. They are found in various habitats, from freshwater rivers and lakes to brackish coastal areas, adapting to a range of salinity levels. This adaptability makes them resilient and popular in the aquarium trade.
Pictures
Bought by aqua-fish.net from jjphoto.dk