Phylogeography of the Patagonian otter Lontra provocax : adaptive divergence to marine habitat or signature of southern glacial refugia?

BMC Evolutionary Biology

Gonzalo Medina-Vogel¹  Walter Sielfeld²  Carlos Olavarra³  Juliana A Vianna⁴  Claudio Chehbar⁵ 

[1] Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biolgicas, Pontificia Universidad Catlica de Chile, Santiago, Chile;Delegacin Regional Patagonia, Administracin de Parques Nacionales, San Carlos de Bariloche, Argentina;Departamento de Ciencias del Mar, Universidad Arturo Prat, Iquique, Chile;Departamento de Ecologa y Biodiversidad, Facultad de Ecologa y Recursos Naturales, Universidad Andrs Bello, Santiago, Chile;Departamento de Ecosistemas y Medio Ambiente, Facultad de Agronoma e Ingeniera Forestal, Pontificia Universidad Catlica de Chile, Santiago, Chile

关键词: Freshwater Habitat;    Marine Habitat;    Glaciate Area;    Bayesian Skyline Plot;    Freshwater Crab;   

DOI  :  10.1186/1471-2148-11-53

学科分类：生物科学（综合）

来源: BioMed Central

【 摘 要 】

A number of studies have described the extension of ice cover in western Patagonia during the Last Glacial Maximum, providing evidence of a complete cover of terrestrial habitat from 41°S to 56°S and two main refugia, one in south-eastern Tierra del Fuego and the other north of the Chiloé Island. However, recent evidence of high genetic diversity in Patagonian river species suggests the existence of aquatic refugia in this region. Here, we further test this hypothesis based on phylogeographic inferences from a semi-aquatic species that is a top predator of river and marine fauna, the huillín or Southern river otter (Lontra provocax). We examined mtDNA sequences of the control region, ND5 and Cytochrome-b (2151 bp in total) in 75 samples of L. provocax from 21 locations in river and marine habitats. Phylogenetic analysis illustrates two main divergent clades for L. provocax in continental freshwater habitat. A highly diverse clade was represented by haplotypes from the marine habitat of the Southern Fjords and Channels (SFC) region (43°38' to 53°08'S), whereas only one of these haplotypes was paraphyletic and associated with northern river haplotypes. Our data support the hypothesis of the persistence of L. provocax in western Patagonia, south of the ice sheet limit, during last glacial maximum (41°S latitude). This limit also corresponds to a strong environmental change, which might have spurred L. provocax differentiation between the two environments.

【 授权许可】

CC BY