Fin's Fish Guide
The Short-finned molly (Poecilia sphenops) is a fish that lives in both fresh and salt water of the family Poeciliidae that grows up to 8 cm.
Fresh and brackish water of Central America and Mexico, along calm, vegetated banks, streams and estuaries.
Description
The short-finned molly is a livebearing toothcarp of the family Poeciliidae reaching about 8 cm. The silvery-grey body bears rows of small spots; the male is more slender and has a rod-shaped mating organ (gonopodium). The wild form is plain, but the aquarium hobby has countless cultivated forms, including the well-known all-black 'black molly'. The species lives in fresh and brackish water of Central America and Mexico, along quiet, vegetated margins, streams and estuaries. As an omnivore it eats mainly algae and growth, supplemented with midge larvae and plankton. Unlike most fish it is a livebearer: after internal fertilisation the female gives birth to live young. It is one of the most popular aquarium fish.
Frequently asked questions
How do you recognise the Short-finned molly?
The Short-finned molly has a torpedo-shaped body, is mainly silver-grey and shows a spots pattern. Ovoviviparous toothcarp with a short dorsal fin; the male has a rod-shaped mating organ and breeding forms are often uniformly black.
Where does the Short-finned molly live?
The Short-finned molly lives in both fresh and salt water and is mostly found around algae or seagrass beds. Fresh and brackish water of Central America and Mexico, along calm, vegetated banks, streams and estuaries.
How big does the Short-finned molly get?
The Short-finned molly grows to a maximum of about 8 cm. On average the species is around 4 cm.
Is the Short-finned molly dangerous to humans?
No, the Short-finned molly is harmless to humans. None required: this species is harmless to humans.
Is the Short-finned molly edible?
The Short-finned molly is not usually eaten.
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All data
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Appearance
Habitat & distribution
Behaviour & biology
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Status & sources
Same genus Poecilia
More from the family Poeciliidae
Want the complete picture on the Short-finned molly?
Point your camera at the fish and Fin names the species in seconds. Free, and the Short-finned molly is one of 12,519 species in the app.