The More the Better: Genetic Monitoring of Paracentrotus lividus (Lamarck, 1816) Experimental Restockings in Sardinia (Western Mediterranean Sea)

The common purple sea urchin, Paracentrotus lividus, is a widely distributed species in the Mediterranean Sea and the North-East Atlantic Ocean. In recent years, it has been heavily exploited for human consumption, with a drastic reduction in its abundance and increasing interest in the experimental farming of it for commercial and restoration purposes. Using genetic tools, the present research aimed at characterizing the Sardinian wild populations and the genetic differences between wild and hatchery-reared individuals. A substantial reduction in genetic diversity and differentiation from the wild populations was found in the sea urchins from the hatchery, characterized by a very small genetic diversity as well as a high degree of relatedness. The results clearly indicate that the breeders used in the hatchery were insufficient to represent the wild populations; hence, larger numbers should be used in future rearing attempts. Overall, the wild Sardinian populations appear to be weakly differentiated, suggesting a large degree of gene flow between them.