Mitochondrial phylogeography of southern elephant seals (Mirounga leonina) around Antarctic waters with emphasis on the population structure of the colony at Isla 25 de Mayo (King George Island) South Shetland Islands, Antarctic Peninsula

BARRAGÁN-BARRERA, D.C.; RIET SAPRIZA F.G.; QUIROGA ALEJANDRO; MOJICA MONCADA DIEGO; NEGRETE JAVIER; CABLLERO SUSANA

Barcelona

Conferencia; XXXIII Biennial Conference on the Biology of Marine Mammals; 2019

Society for marine mammalogy

The southern elephant seal (SES) (Mirounga leonina) has a circumpolar distribution, breeding mainly on sub-Antarctic islands, and making long trips up to thousands of kilometers between breeding colonies, molting locations and foraging areas. Although individuals show fidelity to a set of established breeding colonies, their migratory habits to forage at sea at large distances from their colonies, may allow long-range gene flow. To assess mitochondrial phylogeography of SES around Antarctic waters, with emphasis on population structure of the colony at Isla 25 de Mayo (62º15?S, 58º39?W), skin samples from free-ranging sub-adult male and adult females SES (n=60) were collected with a remote biopsy dart during 2015-2016 austral summer. The mitochondrial DNA Control Region (mtDNA-CR, 325bp) and 10 microsatellite loci were analyzed. The mtDNA-CR results indicate that SES from Isla 25 de Mayo are closely related with individuals from Elephant Island, Livingston Island, and Islas Malvinas (Falkland Islands), but maintain restricted genetic flow with individuals from Victoria Land Coast in the Ross Sea and Macquarie Island. Haplotype diversity was high and similar to the values found at other locations around Antarctica. Microsatellite analyses confirmed data indicated high genetic diversity (allele number ranging between 2 and 12; observed heterozygocity ranging between 0.422 and 0.883). Parentage analyses ran on ML-relate software identified 2% of individuals in the sample as mother-offspring, 16% as full/half siblings and 82% as unrelated individuals. These results agree with previous findings of long-distance genetic dispersal mediated mainly by SES males. Migration, accompanied by high genetic diversity may facilitate dispersal and discovery of emergent habitats, particularly in the potential loss of habitat due to climate change.