Barrens Top Minnows, Fundulus julisia

Barrens Top Minnow Population Monitoring

Monitoring of Barrens Top Minnows, Fundulus julisia, began several years ago.  This species occupies springs and spring influenced streams in the Barrens of southeastern middle Tennessee.  Barrens top minnows prefer submergent vegetation for egg laying, but this is not a requirement.  This species is short lived, living approximately three years in the wild.  Brightly colored males are easily preyed upon.  Population declines are strongly linked to the presence of the Western Mosquitofish, Gambusia affinis.

Monitoring efforts take place during the winter with biologists seining habitats to census populations.  Three passes are made with the seines with all fish being identified and counted.  During the summer months, the water levels of some springs are checked frequently, especially during times of drought.  Some springs may dry completely potentially resulting in the loss of an entire population.  If it is thought a spring will completely dry, biologists remove all Barrens Top Minnows and take them to a facility where they are maintained until typical hydrology resumes.