Vitalite des juveniles du petoncle geant, Placopecten magellanicus (Gmelin, 1791): Impacts de la provenance et des conditions environnementales (French and English text)

The survival of juveniles released onto the seabed is of major importance in the success of programs seeking to enhance scallop populations. Swimming is central in the capacity of scallops to escape predators. We examined the impact of several treatments regularly employed in scallop culture upon the escape responses and physiological properties of juvenile sea scallops ( Placopecten magellanicus). When scallops were transferred from warmer to colder waters (simulating the thermal stress associated with reseeding), both the escape response and recuperation from exhaustive escape responses were markedly slowed and only partially recovered within 6 d following cold shock. However, escape performance was not modified by 4 h air exposure. Cultured scallops had larger somatic tissues, as well as higher muscle energetic contents than their wild counterparts. Nevertheless, wild scallops showed stronger shells and more vigorous escape responses to the starfish predator Asterias vulgaris. Such characteristics may favor higher survival of wild scallops in the field.