title: Insights about the genetic diversity and population structure of an offshore group of common bottlenose dolphins (Tursiops truncatus) in the Mid-Atlantic.
abstract: Although the genus Tursiops has a worldwide distribution and is globally well-studied, some dolphin populations continue to face high risks of decline. Hence, it is necessary to assess the genetic diversity and structure of this genus to properly assess its conservation status and to implement appropriate management actions. In Brazil, genetic studies on this group remain rare, particularly for populations inhabiting offshore waters. Saint Peter and Saint Paul Archipelago (SPSPA) is a small group of islands located in the Mid- Atlantic Ridge, where recent studies of the Tursiops truncatus group indicate that individuals are resident throughout the year around the archipelago, exhibiting considerable site fidelity. A previous study with this group indicated that the individuals form an isolated population. To test this hypothesis, and describe the genetic diversity of SPSPA individuals, we assessed 12 microsatellite loci and a portion of the mitochondrial control region. Bayesian analysis revealed that SPSPA bottlenose dolphins form a unique population. In a phylogeographic perspective, we found that individuals from SPSPA shared mtDNA haplotypes with inshore and offshore individuals from North Atlantic, suggesting that they are not currently isolated from their conspecifics. Mirroring mtDNA findings, microsatellite analysis revealed that most of the pairs of individuals sampled seem to be unrelated (83.8%) and no indication of inbreeding, what would be expected if a small population such as SPSPA was reproductively isolated.
authors.affiliation: Laboratório de Ecologia da Paisagem e Conservação, Departamento de Ecologia, Universidade de São Paulo, São Paulo, SP, Brasil cscastilho@ib.usp.br.
authors.forename: C S
authors.initials: CS
authors.lastname: Castilho
authors.affiliation: Laboratório de Citogenética e Evolução, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
authors.forename: F
authors.initials: F
authors.lastname: Pedone-Valdez
authors.affiliation: Laboratório de Citogenética e Evolução, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
authors.forename: F
authors.initials: F
authors.lastname: Bertuol
authors.affiliation: Molecular Ecology Laboratory, Flinders University, Adelaide, SA, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Fruet
authors.affiliation: Laboratório de Mamíferos Marinhos, Museu Oceanográfico, Universidade Federal de Rio Grande, Rio Grande, RS, Brasil.
authors.forename: R C
authors.initials: RC
authors.lastname: Genoves
authors.affiliation: Laboratório de Mamíferos Marinhos, Museu Oceanográfico, Universidade Federal de Rio Grande, Rio Grande, RS, Brasil.
authors.forename: J C
authors.initials: JC
authors.lastname: Di Tullio
authors.affiliation: Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
authors.forename: G
authors.initials: G
authors.lastname: Caon
authors.affiliation: Museu de Ciências Naturais da Fundação Zoobotânica do Rio Grande do Sul, Porto Alegre, RS, Brasil.
authors.forename: L S
authors.initials: LS
authors.lastname: Hoffmann
authors.affiliation: Laboratório de Citogenética e Evolução, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
authors.forename: T R O
authors.initials: TR
authors.lastname: Freitas
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D001499:Bayes Theorem; D050681:Bottle-Nosed Dolphin / Q000235:genetics*; D001938:Brazil; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D062312:Islands; D019901:Locus Control Region; D008297:Male; D018895:Microsatellite Repeats; D010375:Pedigree; D010802:Phylogeny; D058974:Phylogeography; D017422:Sequence Analysis, DNA; D012744:Sex Ratio
chemical_list: D004272:DNA, Mitochondrial