Low levels of population genetic structure in the gilthead sea bream, Sparus aurata, along the coast of Italy

Abstract

Franchini, P., Sola, L., Crosetti, D., Milana, V., and Rossi, A. R. 2012. Low levels of population genetic structure in the gilthead sea bream, Sparus aurata, along the coast of Italy. – ICES Journal of Marine Science, 69: 41–50. The gilthead sea bream, Sparus aurata, is a coastal, commercially important fish. Contrasting results concerning the genetic structure of the species at different geographic scales have been reported. Here, an investigation is made into the population genetic structure of S. aurata along the coast of Italy, using samples analysed previously and material from new sampling sites (12) and using different microsatellite loci (10). One sample from the eastern Atlantic and three temporal replicates from one site were also included. The presence of a weak (overall FST = 0.0072), but significant, genetic population subdivision was detected by F-statistics. Temporal replicates indicate genetic data consistency over time. Isolation by distance between the Atlantic and the coast of Italy is suggested by a Mantel test. The distributional pattern of genetic variance obtained by analysis of molecular variation reflects the geographic sampling areas, but is only partially congruent with the results obtained with fewer sites and loci. The dispersal of passive eggs/larvae by the main currents appears to contribute to shaping the gene flow. Given the intensity of sea bream aquaculture activities in Italy, the possibility that aquaculture may have partially contributed to the population genetic pattern detected cannot be excluded.

Spatial genetic structure in the saddled sea bream (Oblada melanura [Linnaeus, 1758]) suggests multi-scaled patterns of connectivity between protected and unprotected areas in the Western Mediterranean Sea

“…Similar results were recorded, for the same species, using a different set of microsatellite primers (Gkafas et al, 2013), and in other sparid fish in the Mediterranean Sea (Franchini et al, 2011). High genetic diversity is fundamental for maintaining the adaptability of natural fish populations and sustainable yields in fisheries (Kenchington et al, 2003).…”

Morphological and molecular differentiation of wild and farmed gilthead sea bream Sparus aurata: implications for management

“…The long culture period carried out over the past decade may have contributed to wild population homogenization, as was reported for wild populations sampled along the Italian coast (Franchini et al 2012) and in Atlantic salmon (Glover et al 2012). However, the population structure of gilthead sea bream is still unclear and does not appear to be associated with geographic or oceanographic factors (Alarcón et al 2004, Ben Slimen et al 2004, De Innocentiis et al 2004, Rossi et al 2006.…”

Development of the first standardised panel of two new microsatellite multiplex PCRs for gilthead seabream (Sparus aurata L.)

“…The levels of genetic differentiation or similarity inferred by neutral molecular markers represent a basic source of information for reconstructing the life history of a species and for inferring the actual situation in terms of gene flow (Franchini et al 2012). The levels of genetic differentiation or similarity inferred by neutral molecular markers represent a basic source of information for reconstructing the life history of a species and for inferring the actual situation in terms of gene flow (Franchini et al 2012).…”