Poeciliidae

Four hooked mosquitofish

Gambusia quadruncus

• Tropical
• Regional distribution
• Freshwater fish
• Central America and the Caribbean
• North America
• Fusiform
• Small
• Tropical fish

Gambusia quadruncus, known as the llanos mosquitofish, is a species of bony fish in the genus Gambusia, part of the family Poeciliidae, that lives in east-central Mexico. Sometimes coexisting with at least three similar species, it differs from its closest relative, Gambusia affinis, in several characteristics with plausible effects on reproductive isolation. "Combined analysis of mitochondrial and nuclear gene sequence data indicates reciprocal monophyly of the species and its sister species Gambusia affinis, with levels of genetic divergence suggesting the two species diverged from one another over a million years ago.