Meeting Abstract
The Southern Ocean is a unique ecosystem characterized by a highly endemic benthic fauna. Brittle stars or ophiuroids in particular are a highly abundant and conspicuous member of the benthic assemblage, often dominating in abundance at many sampling localities. Here we present a large scale phylogeographic analyses in the Southern Ocean comparing two highly abundant ophiuroid species, Ophionotus victoriae and Astrotoma agassizii. While these two species differ in reproductive strategy and feeding behavior, they both occupy extensive ranges throughout the Antarctic continental shelf post glacial maximas of the Cenozoic. O. victoraie is endemic to the Southern Ocean but A. agassizii is known to occur on both sides of the Antarctic Circumpolar Current, in the Southern Ocean and in the waters surrounding South America. In this study, we build upon the previous mitochondrial work for these two species but focus on 2b-RAD as a high resolution whole genome approach in efforts to recover genetic structure at a resolution that is not capable with traditional molecular markers. Through the use of 2b-RAD for phylogeographic analyses, we are assessing gene flow in both species and are particularly interested in the effects of Southern Ocean currents, breaks in the Antarctic shelf and open ocean barriers of dispersal have on genetic connectivity for these species.
