GENETIC VARIABILITY AND GEOGRAPHIC ORIGIN OF GILTHEAD SEABREAM BROODSTOCKS FROM ITALIAN COMMERCIAL HATCHERIES

摘要

A genetic characterization of the gilthead sea bream, Spams auratus, was undertaken to investigate the genetic variability and divergence of cultured stocks, through the analysis of broodstocks from several Italian commercial hatcheries. Indeed, determination of seed origin is essential for a sustainable use of aquatic resources, in order to protect local biodiversity in restocking programmes or culture-based fisheries and as a precautional approach to mitigate the genetic impact of accidental escapees from fish farms. Gilthead sea bream is one of the most important species in Mediterranean aquaculture. Hatchery juveniles are either grown to commercial size in intensive culture systems, floating cages for the most, or released in coastal lagoons forrestocking purposes, and both actions might cause spread of non-native genotypes in the wild. A common practice in Mediterranean fish hatcheries is to breed gilthead seabreams from Atlantic broodstocks, as the Atlantic form is particularly appreciated by fish farmers for its shape and growth performance.