Cauca molly
The Cauca molly (Poecilia caucana) is a small freshwater fish from the livebearing family Poeciliidae. It lives in shallow rivers and streams in tropical Central and South America, including Panama, Venezuela, and Colombia. Its range covers the Lebrija, Magdalena, Cauca river basins, the Catatumbo River in northern Colombia, and Lake Maracaibo in Venezuela.
Males grow to about 3 cm (1.2 in) and females up to about 6 cm (2.4 in). It is usually silvery with a distinctive black blotch at the base of the dorsal fin, and some individuals show narrow banding during breeding.
It eats algae, mosquito larvae, and insects that fall on the water surface. It is a hardy, adaptable species that can tolerate temperature changes, varying salinity, and low oxygen. It is a livebearer: females give birth to 10–25 young after about four weeks of gestation.
In aquariums, it does well in water around 27–29 C (80–84 F) with good aeration and a pH of 7.0–7.5. Because it eats mosquito larvae, it has been considered for biological mosquito control along with the closely related guppy.
This page was last edited on 3 February 2026, at 16:09 (CET).