Gene flow by larval dispersal in the Antarctic notothenioid fish Gobionotothen gibberifrons

The diversification of the teleost suborder Notothenioidei (Perciformes) in Antarctic waters provides one of the most striking examples of a marine adaptive radiation. Along with a number of adaptations to the cold environment, such as the evolution of antifreeze glycoproteins, notothenioids diversified into eight families and at least 130 species. Here, we investigate the genetic population structure of the humped rockcod (Gobionotothen gibberifrons), a benthic notothenioid fish. Six populations were sampled at different locations around the Scotia Sea, comprising a large part of the species’ distribution range (N=165). Our analyses based on mitochondrial DNA sequence data (352 bp) and eight microsatellite markers reveal a lack of genetic structuring over large geographic distances (ΦST≤0.058, F ST≤0.005, p-values nonsignificant). In order to test whether this was due to passive larval dispersal, we used GPS-tracked drifter trajectories, which approximate movement of passive surface pa...