Kelly Johnson
M.S. student
Education: Bachelor of Science in Zoology. 2000. North Dakota State University.
Research topic: Phylogeography of Bermudian shorefishes
Bermuda, located in the tropical Western Atlantic, includes the northernmost coral reef system in the world. During the last glacial period 18,000 years ago, it is believed that low sea levels and cooler water temperatures resulted in the extirpation of local populations of tropical and subtropical marine shore fishes, including endemic species. Bermuda’s present fauna is believed to be the result of re-colonization following the retreat of glacial conditions. If most of the present-day shorefishes of Bermuda are the result of colonization after the last ice age, an opportunity arises to address several questions of evolutionary significance. What relationships exist between conspecifics in Bermuda and the United States, a potential source of colonists? What is the relative level of genetic variation in U.S. and Bermudian populations? Are the levels of genetic divergence between U.S. and Bermudian populations similar in each species? I am attempting to answer these questions using sequence analysis of both the nuclear ITS region in the ribosomal RNA gene complex and the mitochondrial control region from Bermudian populations and conspecific populations along the Atlantic coast of the southeast United States. Species being tested include gray snapper (Lutjanus griseus), french grunt (Haemulon flavolineatum), blue-striped grunt (Haemulon sciurus), tomtate (Haemulon aurolineatum), common squirrelfish (Holocentrus ascensionis), longspine squirrelfish (Holocentrus rufus), the Bermuda anchovy (Anchoa choerostoma), the bay anchovy (Anchoa mitchilli), and the striped anchovy (Anchoa hepsetus). Further analysis will include species of anchovy from the Caribbean.