Fin's Fish Guide
The Shortfin molly (Poecilia mexicana) is a fish that lives in both fresh and salt water of the family Poeciliidae that grows up to 11 cm.
Central America from Mexico southwards, in ditches, streams, pools and estuaries; extremely tolerant, lives even in sulphurous springs and tolerates brackish water.
Description
The shortfin molly is a small, hardy livebearer of the family Poeciliidae (livebearing toothcarps) reaching about 11 cm. The silvery-grey body has an upturned mouth and often rows of dark spots; the male is smaller, courts vigorously and has the anal fin modified into a rod-shaped mating organ (gonopodium). Like relatives such as the guppy it is a livebearer and gives birth to live young. The species comes from Central America and is extraordinarily tolerant: it lives in ditches, streams, pools and estuaries, tolerates brackish water and even sulphur-rich springs. As an omnivore it eats algae, detritus, zooplankton and insect larvae. It is hardy and popular in the aquarium hobby.
Frequently asked questions
How do you recognise the Shortfin molly?
The Shortfin molly has an elongate, eel-like body, is mainly silver-grey and shows a spots pattern. Small, hardy ovoviviparous fish with an upturned mouth; the male has a rod-shaped mating fin (gonopodium) and displays vigorously.
Where does the Shortfin molly live?
The Shortfin molly lives in both fresh and salt water and is mostly found around algae or seagrass beds. Central America from Mexico southwards, in ditches, streams, pools and estuaries; extremely tolerant, lives even in sulphurous springs and tolerates brackish water.
How big does the Shortfin molly get?
The Shortfin molly grows to a maximum of about 11 cm. On average the species is around 4 cm.
Is the Shortfin molly dangerous to humans?
No, the Shortfin molly is harmless to humans. None required: this species is harmless to humans.
Is the Shortfin molly edible?
The Shortfin molly is not usually eaten.
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All data
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Status & sources
Same genus Poecilia
More from the family Poeciliidae
Want the complete picture on the Shortfin molly?
Point your camera at the fish and Fin names the species in seconds. Free, and the Shortfin molly is one of 12,519 species in the app.