Low level of genetic divergence between Harpagifer fish species (Perciformes: Notothenioidei) suggests a Quaternary colonization of Patagonia from the Antarctic Peninsula

HUNE, MATÍAS; GONZÁLESZ-WEBAR, CLAUDIO; POULIN, ELIE; MANSILLA, ANDRÉS; FERNÁNDEZ, DANIEL A.; BARRERA-ORO, ESTEBAN

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2015 vol. 38 p. 607 - 617

0722-4060

Abstract The evolution of the marine benthic fauna ofAntarctica has been shaped by geological and climaticatmospheric factors such as the geographic isolation of thecontinent and the subsequent installation of the AntarcticCircumpolar Current (ACC). Despite this isolation process,strong biogeographic links still exist between marine faunafrom the Antarctic Peninsula and southern South America.Recent studies in different taxa have shown, for example, thatshallow benthic organisms with long larval stages maintainedcontact after the physical separation of the continents anddivergence may be associated with the intensification of theACC in the late Miocene?early Pliocene. In this context,here we performed phylogenetic reconstructions and estimatedthe level of molecular divergence between congenericspecies of Harpagifer, a marine notothenioid from the AntarcticPeninsula (Harpagifer antarcticus) and Patagonia(H. bispinis) using the mitochondrial control region. Phylogenieswere reconstructed using Maximum Parsimony andBayesian Inference, while the divergence time of H. antarcticusand H. bispinis was estimated following a relaxedBayesian approach and assuming a strict molecular clockhypothesis. According to our estimation, the divergencebetween H. bispinis and H. antarcticus is more recent thanexpected if it was associated with the intensification of theACC during the mid to late Miocene. We propose that climaticand oceanographic changes during the coldest periodsof the Quaternary (i.e., Great Patagonian Glaciation,1?0.9 Ma) and the northward migration of the Antarctic PolarFront may have assisted the colonization of southern SouthAmerica by Harpagifer, from the Antarctic Peninsula via theScotia Arc Islands.