Polar Biol DOI 10.1007/s00300-014-1623-6 ORIGINAL PAPER Low level of genetic divergence between Harpagifer fish species (Perciformes: Notothenioidei) suggests a Quaternary colonization of Patagonia from the Antarctic Peninsula Mathias Hu¨ne • Claudio Gonza´lez-Wevar • Elie Poulin • Andre´s Mansilla • Daniel A. Ferna´ndez • Esteban Barrera-Oro Received: 16 January 2014 / Revised: 14 November 2014 / Accepted: 17 November 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract The evolution of the marine benthic fauna of (H. bispinis) using the mitochondrial control region. Phy- Antarctica has been shaped by geological and climatic logenies were reconstructed using Maximum Parsimony and atmospheric factors such as the geographic isolation of the Bayesian Inference, while the divergence time of H. antarc- continent and the subsequent installation of the Antarctic ticus and H. bispinis was estimated following a relaxed Circumpolar Current (ACC). Despite this isolation process, Bayesian approach and assuming a strict molecular clock strong biogeographic links still exist between marine fauna hypothesis. According to our estimation, the divergence from the Antarctic Peninsula and southern South America. between H. bispinis and H. antarcticus is more recent than Recent studies in different taxa have shown, for example, that expected if it was associated with the intensification of the shallow benthic organisms with long larval stages maintained ACC during the mid to late Miocene. We propose that cli- contact after the physical separation of the continents and matic and oceanographic changes during the coldest periods divergence may be associated with the intensification of the of the Quaternary (i.e., Great Patagonian Glaciation, ACC in the late Miocene—early Pliocene. In this context, 1–0.9 Ma) and the northward migration of the Antarctic Polar here we performed phylogenetic reconstructions and esti- Front may have assisted the colonization of southern South mated the level of molecular divergence between congeneric America by Harpagifer, from the Antarctic Peninsula via the species of Harpagifer, a marine notothenioid from the Ant- Scotia Arc Islands. arctic Peninsula (Harpagifer antarcticus) and Patagonia Keywords mtDNA control region Á Southern Ocean Á Antarctic Polar Front Á Great Patagonian Glaciation Á Electronic supplementary material The online version of this Long-distance dispersal article (doi:10.1007/s00300-014-1623-6) contains supplementary material, which is available to authorized users. C. Gonza´lez-Wevar M. Hu¨ne (&) Á C. Gonza´lez-Wevar Á E. Poulin Á A. Mansilla GAIA-Anta´rtica, Universidad de Magallanes, Avenida Bulnes Instituto de Ecologı´a y Biodiversidad (IEB), Casilla 653, 01890, 621-0427 Punta Arenas, Chile Santiago, Chile e-mail: [email protected] D. A. Ferna´ndez Centro Austral de Investigaciones Cientı´ficas (CADIC- M. Hu¨ne Á C. Gonza´lez-Wevar Á E. Poulin CONICET), Bernardo Houssay 200, Ushuaia, Argentina Laboratorio de Ecologı´a Molecular (LEM), Departamento de Ciencias Ecolo´gicas, Universidad de Chile, Las Palmeras 3425, E. Barrera-Oro N˜ un˜oa, Santiago, Chile Instituto Anta´rtico Argentino, Cerrito 1248, Buenos Aires, Argentina M. Hu¨ne Á A. Mansilla Departamento de Recursos Naturales, Universidad de Magallanes, Avenida Bulnes 01855, Punta Arenas, Chile M. Hu¨ne Fundacio´n Ictiolo´gica, Pedro de Valdivia 2086/406, Santiago, Chile 123 Polar Biol Introduction fishes (Clarke and Johnston 1996). While most of the tel- eost groups were completely eradicated from Antarctica, The Southern Ocean (SO) and particularly the coastal this suborder dominates in diversity, abundance and bio- Antarctic waters constitutes a unique marine environment mass (Eastman 2005). The evolutionary success of the for biogeographic studies, considering its isolation and the Notothenioidei in subzero ecosystems has been explained high levels of endemism of the fish fauna (Bargelloni et al. by the presence of antifreeze glycoproteins, a key inno- 2000; Clark et al. 2004; Peck et al. 2005; Aronson et al. vation in this Antarctic group (Cheng and DeVries 1991; 2007). Geological processes in the SO since the Mesozoic Eastman 1993; Cheng 1998). Nevertheless, recent molec- influenced oceanographic and climatic changes that are ular study indicates that the most species-rich lineages responsible for the current biogeography of the region within the notothenioids diversified and evolved during the (Crame 1999; Zachos et al. 2001; Griffiths et al. 2009). For late Miocene (11.6–5.3 Ma), 10 Ma after the acquisition of instance, the opening of the Tasman Gateway and the antifreeze glycoproteins (Near et al. 2012). Drake Passage were responsible for the separation of Despite the historical isolation of the Antarctic, a strong Antarctica, Australia and South America (Lawver et al. biogeographic link exists between the marine benthic fauna 2003; Barker et al. 2007). The fragmentation and disper- of Antarctica and the southern tip of South America (Arntz sion of the continental blocks that formed Gondwana et al. 2005). The accepted explanation for this affinity relies allowed the formation of the Antarctic Circumpolar Cur- on the fact that these continents were contiguous until the rent (ACC). According to Crame (1999), this oceano- opening of the Drake Passage and drifted apart progres- graphic feature represents a barrier since the Eocene– sively (Crame 1999). Several authors have suggested that Oligocene boundary. Concurrently, the distance between this connection was possible through the seamounts of the continents allowed a gradual bathymetric isolation through Scotia Arc (Clarke and Crame 1997; Bargelloni et al. 2000; the formation of deep zones around Antarctica (Clarke Clarke et al. 2005; Strugnell et al. 2008;Dı´az et al. 2011). et al. 2005). Different taxa including marine invertebrates such as The oxygen (d18O) isotope in the deep sea shows an Euphausia sp. (Patarnello et al. 1996) and fish (Clarke and overall cooling trend of about 14 °C since the early Eocene Johnston 1996) exhibit high levels of genetic divergence (Zachos et al. 2008) resulting in the expansion of the between provinces of the SO, supporting vicariance spe- Antarctic cryosphere in the late Eocene (Oi-1 glaciation; ciation associated with continental drift. However, recent Zachos et al. 1996, 2001; DeConto and Pollard 2003; molecular studies in marine organisms with high dispersal Mackensen 2004; Pagani et al. 2005). During the mid- potential from Antarctica and South America suggest more Miocene, Sea Surface Temperatures (SST), salinity and ice recent divergence, providing evidence of connectivity volume trends suggest an intensification of the ACC that between these provinces after their physical separation presumably affected the meridional heat/vapor transport, (Helmuth et al. 1994; Page and Linse 2002; Thornhill et al. triggering global cooling and the initiation of subzero polar 2008; Wilson et al. 2009;Dı´az et al. 2011; Gonza´lez- conditions in the SO (Nong et al. 2000; Zachos et al. 2001; Wevar et al. 2012; Poulin et al. 2014). Recent studies in the Shevenell et al. 2004; Lewis et al. 2008). The Pliocene Central Scotia Ridge indicate that a remnant, now sub- (5.33–2.58 Ma) is marked by the onset of climate vari- merged volcanic arc may have formed a barrier to deep ability that increased particularly during the Quaternary eastward circulation until *11.6 Ma (Dalziel et al. 2013). glacial cycles (1.8 Ma–10 ka) (Zachos et al. 2001). These The formation of a full deep ACC may have played a key glacial–interglacial processes have caused fluctuations in role in the subsequent expansion of the Antarctic cryo- temperature and sea level, as well as ice sheet advances and sphere (Lear et al. 2000; Zachos et al. 2001), as well as in retreats over the continental shelves at higher latitudes an intensification of the ACC associated with an increase in (Hewitt 2000, 2004; Thatje et al. 2005). In this context, the the strength of westerly winds (Flower and Kennett 1994; SO marine benthic fauna has been shaped by the interac- Shevenell et al. 2004). Hence, the full development of a tion of geological, oceanographic and climatic events, deep ACC was not achieved during the Eocene/Oligocene manifested for example in the absence of durophagous boundary (*33.9 Ma), as long surmised, but only in the predators such as decapod crustaceans and most teleost fish late Miocene (Dalziel et al. 2013). It may be envisioned (Aronson et al. 2007). However, some invertebrate groups that such changes created the characteristic polar condi- including bryozoans, polychaetes, amphipods, pycnogonids tions of the region that are responsible for the thermal and and echinoderms are abundant and diverse, suggesting that physical barriers that isolated the marine fauna of the environmental changes have not impeded their evolution- Southern Ocean continental shelves. As previously stated, ary success (Clarke and Johnston 1996). One of the most molecular-based analyses comparing Antarctic and South remarkable processes of diversification in the Antarctic American congeneric taxa (Gonza´lez-Wevar et al. 2012; realm is the evolution of the cold-adapted notothenioid Poulin et al. 2014) suggest more recent separation 123 Polar Biol processes associated with major oceanographic changes CT-30; CR-HarpaR (50-AGA GTG AAG GGG TGT CAG related to the final establishment of a full deep ACC. AAG C-30) based on H. antarcticus control region In this study, we performed phylogenetic reconstruction sequences (Zhuang and Cheng 2010). Amplifications were and estimated the levels of molecular divergence and performed in a 25-ll reaction containing 5 ll59 Buffer genetic diversity between two congeneric species from the (50 mM KCl, 10 mM Tris–HCl, pH 8.0), 2.0 ll25mM Antarctic Peninsula and southern South America of the MgCl2, 100 mM dNTPs, 0.5 ll each primer (10 pg/ll), 5 U spiny plunderfish (Harpagiferinae, as recently proposed by Taq (Promega), 12.2 ll double-distilled water and 25 ng Duhamel et al. 2014) a marine notothenioid that has one DNA. Thermal cycling parameters included an initial genus, Harpagifer, with 10 species currently described.