Restricted geographic distribution and low genetic diversity of the brooding sea urchin Abatus agassizii (Spatangoidea: Schizasteridae) in the South Shetland Islands: A bridgehead population before the spread to the northern Antarctic Peninsula?

• Published in: Revista chilena de historia natural
• Main Authors: Díaz, Angie, González Wevar, Claudio, Maturana, Claudia S., Palma, Álvaro T., Poulin, Elie, Gerard, Karin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Sociedad de Biologia de Chile 2012
• Subjects: Antarctic benthic fauna; COI phylogenetic relationships; King George Island; Southern Ocean; Survivor population; Antarctic; Antarctic Peninsula; Fildes; South Shetland Islands; The Antarctic; Antarc*; Antarctica; Ice Sheet
• Online Access: https://doi.org/10.4067/S0716-078X2012000400008; https://repositorio.uchile.cl/handle/2250/165922

The glacial cycles of the Pleistocene have promoted the principal climatic changes of the Southern Ocean, and motivated scientific interest regarding the strategies developed by marine benthic invertebrates to tolerate and overcome the extension and contraction of the ice sheet on the Antarctic continental platform. A recent study of the bathymetric zonation and distribution of macro-invertebrates in a shallow subtidal area of Fildes Bay (King George Island, South Shetlands Islands, Antarctica) highlighted the presence of a large aggregation of the brooding sea urchin Abatus agassizii, whose geographic distribution is known only for localities south of the Antarctic convergence (Antarctic Peninsula and South Shetland and South Georgia Islands in the Scotia Arc). Its presence is atypical, given that these shallow populations should have been erased from the vicinity of the Antarctic Peninsula by the advances and retreats of the ice sheet, and the absence of a larval stage associated wit