Microsatellite markers for assessing genetic diversity and kinship relationships in one of the largest South American fur seal (Arctocephalus australis) populations of the Pacific Ocean

The genetic diversity of a population is the foundation of its
adaptability to environmental challenges. The South American fur seal is a
widely distributed pinniped in the south cone of South America. However, a
large gap in the Pacific coast separates two distinct evolutionary units
for the species: the Peruvian and the Southern Pacific/Atlantic
populations. Throughout the Pacific, one of the main breeding colonies is
located in Guafo Island, in the southern Chilean Patagonia. As the closest
reproductive population to the isolated Peruvian group, Guafo’s colony may
potentially facilitate gene flow, contribute with new alleles and increase
genetic variability to Peruvian populations’, connecting the entire
Pacific’s distribution of the species. In this study, Guafo’s Island South
American fur seal population was characterized by the identification and
genotyping of species-specific microsatellite markers. As a result, we
confirm that Guafo’s colony is a diverse group with mild evidence of
genetic structure. Although a couple of family groups among seasons were
observed, results indicate that half-siblings are rare and suggest that
polygyny in this species is more relaxed than previously thought.
Additionally, three full-sibling pairs were genetically identified within
the 2017 season, which is the first genetic support that describes the
presence of twins for the species. These attributes suggest that the
colony at Guafo is a panmictic large group, and could serve as a potential
genetic source for other isolated populations.