Biogeography of the Genus Ephemerella in Western Montana
Mentor:Kathleen Weaver, Associate Professor of Biology, University of La Verne
Ephemeropterans (mayflies) have a two-stage life cycle. They are aquatic nymphs for most of their life, about three months, and emerge as flying adults for typically 12 to 36 hours. During this adult stage, mayflies lose their functioning mouthparts and can only mate. Despite their short terrestrial life span, ephemeropteran species are widely distributed. Our study focuses on the biogeography of ephemeropterans, given the apparent paradox of their large distributions, yet limited dispersal. In order to document gene flow between populations, we collected mayflies of the genus Ephemerella from 15 streams and creeks around the Clark Fork River, in Granite County, Montana as well as one stream east of the continental divide approximately 100 miles away. We then extracted DNA from the abdomen and performed polymerase chain reaction, with the common bar coding gene, cytochrome oxidase I (COI), as it is often used to distinguish groups at the species level. Each mayfly was sequenced, and we constructed a phylogenetic tree to interpret relationships. Preliminary results suggest a high degree of mobility of the genus Ephemerella within the Clark Fork River region.