Restricted gene flow and evolutionary divergence between geographically separated populations of the Antarctic octopus Pareledone turqueti

Samples of the Antarctic octopus Pareledone turqueti were taken from three locations on the Scotia Ridge in the Southern Ocean. The genetic homogeneity of these populations was investigated using isozyme electrophoresis. Whilst panmixia appeared to be maintained around South Georgia (F(ST) = 0) gene flow between this island and Shag Rocks, an island only 150 km away but separated by great depths, was extremely limited (F(ST) = 0.74). These results are examined with respect to the discontinuous distribution of P. turqueti throughout Antarctica. An estimate of effective population size was also calculated (N(e) = 3600).