Genetic variation and population structure of krill (Euphausia superba) in the Atlantic sector of Antarctic waters and off the Antarctic peninsula

Summary Samples of Antarctic krill Euphausia superba from 16 locations in the Weddell Sea, Scotia Sea and on the west coast of the Antarctic Peninsula were analysed for protein variation using enzyme electrophoresis techniques. Analysis of allele distributions indicate that samples from all locations are part of a single breeding population of krill. Significant departures from random mating expectations were observed in the distribution of electrophoretic phenotypes of the enzymes esterase and glucose phosphate isomerase. Possible explorations of these results are advanced, but they do not materially affect conclusions concerning population structure. The spatial and temporal distribution of electrophoretically detected genetic variation in Atlantic and Pacific sector krill stocks is discussed by comparing the results of this study with those of previous authors working with E. superba.