title: Genetic structure of bluefin tuna in the mediterranean sea correlates with environmental variables.
abstract: BACKGROUND
  Atlantic Bluefin Tuna (ABFT) shows complex demography and ecological variation in the Mediterranean Sea. Genetic surveys have detected significant, although weak, signals of population structuring; catch series analyses and tagging programs identified complex ABFT spatial dynamics and migration patterns. Here, we tested the hypothesis that the genetic structure of the ABFT in the Mediterranean is correlated with mean surface temperature and salinity.
  
  
  METHODS
  We used six samples collected from Western and Central Mediterranean integrated with a new sample collected from the recently identified easternmost reproductive area of Levantine Sea. To assess population structure in the Mediterranean we used a multidisciplinary framework combining classical population genetics, spatial and Bayesian clustering methods and a multivariate approach based on factor analysis.
  
  
  CONCLUSIONS
  FST analysis and Bayesian clustering methods detected several subpopulations in the Mediterranean, a result also supported by multivariate analyses. In addition, we identified significant correlations of genetic diversity with mean salinity and surface temperature values revealing that ABFT is genetically structured along two environmental gradients. These results suggest that a preference for some spawning habitat conditions could contribute to shape ABFT genetic structuring in the Mediterranean. However, further studies should be performed to assess to what extent ABFT spawning behaviour in the Mediterranean Sea can be affected by environmental variation.
authors.affiliation: Marine Biology & Fisheries Laboratory, Department Biological, Geological & Environmental Sciences, University of Bologna, Fano (PU), Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Riccioni
authors.forename: Marco
authors.initials: M
authors.lastname: Stagioni
authors.forename: Monica
authors.initials: M
authors.lastname: Landi
authors.forename: Giorgia
authors.initials: G
authors.lastname: Ferrara
authors.forename: Guido
authors.initials: G
authors.lastname: Barbujani
authors.forename: Fausto
authors.initials: F
authors.lastname: Tinti
mesh_terms: D025041:Animal Migration; D000818:Animals; D001499:Bayes Theorem; D017753:Ecosystem; D004777:Environment; D014644:Genetic Variation / Q000235:genetics*; D005828:Genetics, Population; D008522:Mediterranean Sea; D011157:Population Dynamics; D054712:Salinity; D013696:Temperature; D014413:Tuna / Q000235:genetics*