Population genetic variation of the southern ocean krill, Euphausia superba, in the western Antarctic Peninsula region using Single Nucleotide Polymorphisms (SNPs)

P.G. Batta Lona¹, A.Bucklin¹, P.W. Wiebe², N.J. Copley², and T. Patarnello³

¹Department of Marine Sciences, University of Connecticut, Groton, CT, USA;

²Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA;

³Department of Biology, University of Padova, Padova, Italy

Marguerite Bay, in the Western Antarctic Peninsula (WAP) region, is known to support persistent and large standing stocks of the Southern Ocean krill, Euphausia superba. The circulation pattern of Marguerite Bay provides a retention mechanism for the Antarctic zooplankton. Examination of population genetic diversity and structure of E. superba will allow us to understand the effects of the ocean circulation in population dynamics of this species. In this project, DNA sequence variation of E. superba for the gene encoding mitochondrial cytochrome B (mtCYB) was examined for single nucleotide polymorphisms (SNPs). Samples of krill collected during 2001 and 2002 U.S. GLOBLEC Southern Ocean cruises to the WAP were examined for E. superba. Individual krill were assayed for SNP variation at four sites along the 1200 base-pair sequence. Allelic variation was used to characterize time/space patterns of population genetic variation of E. superba within the WAP, and to test the hypothesis that populations of the Antarctic krill found in Marguerite Bay are genetically differentiated from krill populations found offshore.