Biochemical composition of gonad and muscle in the catarina scallop, Argopecten ventricosus, after reproductive conditioning under two feeding systems

Abstract Favorable nutrition of scallops during reproductive conditioning in hatcheries can be related not only to qualitative and quantitative aspects of diets, but also to the way in which food is supplied. The aim of the present study was to investigate whether continuous rather than discontinuous feeding could improve reproductive performance of Argopecten ventricosus . For this purpose, the influence of two feeding systems (continuous and discontinuous) on gonadosomatic and condition index, and biochemical composition were analyzed in two experiments. In Experiment 1, scallops were induced to spawn and a sample sacrificed after seven days of conditioning. Continuously fed ( C 1 ) spawned scallops showed lower gonadosomatic index (GSI) and a higher dry weight of spawned eggs, compared to discontinuously fed ( D 1 ) scallops. The remaining scallops derived from both feeding systems ( C 1 and D 1 ) during Experiment 1 were conditioned for rematuration under both continuous ( C 2 ) or discontinuous ( D 2 ) feeding during Experiment 2, obtaining in this way a total of four groups: C 1 C 2 , D 1 C 2 , C 1 D 2 , D 1 D 2 . Continuous feeding during this experiment yielded higher GSI, accompanied by increased concentrations of acylglycerol (AG) and cholesterol (CHL) in the groups C 1 C 2 and D 1 C 2 . This result indicated that feeding condition during the first experiment did not detract from the positive response to continuous feeding during the second experiment. The C 1 D 2 group had intermediate values of GSI and AG, and CHL levels equal to those of C 1 C 2 and D 1 C 2 groups, suggesting that better nutrition during the first experiment partially compensated for inadequate nutrition during the second experiment. No significant differences were obtained for other variables such as gonad proteins, muscle condition index, and adductor muscle levels of AG, CHL, proteins, and glycogen. Continuous feeding during conditioning of A. ventricosus thus resulted in a better spawning capacity and increased rematuration ability than discontinuous feeding.