Meeting Abstract

P2.202  Saturday, Jan. 5  Does the Scotia Arc facilitate connectivity between South America and Antarctica? An example from the sea star Porania antarctica MOORE, J. M.*; ROUSE, G. W.; WILSON, N. G.; Scripps Institution of Oceanography; Scripps Institution of Oceanography; The Australian Museum jmoore@ucsd.edu

The Antarctic Circumpolar Current is a potentially powerful isolating force separating the faunas of South America and Antarctica. Marine invertebrates exhibiting distributions on the continental shelves of both Antarctica and South America provide evidence for genetic connection via dispersal across the Polar Front, or alternatively, the existence of cryptic species complexes. This study tested the hypothesis that the islands of the Scotia Arc allow dispersal and gene flow of a sea star with planktonic larvae, Porania antarctica. We sampled 15-20 individuals from 7 sites spanning the Scotia Arc from Burdwood Bank in the southern Atlantic Ocean to Bransfield Strait, Antarctica, as well as additional sites with fewer than 20 individuals. We built multi-gene phylogenetic trees and haplotype networks to test the presence of cryptic species complexes, and used phi-st to infer patterns of genetic connectivity along the Scotia Arc.