Abstract

Recently spawned Argopecten purpuratus broodstock were conditioned at two temperatures and fed three different diets (microalgae, microalgae mixed with lipids and microalgae mixed with carbohydrates) to examine changes in the biochemical composition of gonad and muscle as well as muscle metabolic capacities. During one experiment, scallops were fed at 3% of their dry mass per day whereas during a second experiment, they were fed at 6% of their dry mass per day. During both experiments, total gonadal levels of lipids and protein increased markedly during conditioning with the two mixed diets at 16 degrees C. These increases were less pronounced at 20 degrees C. Carbohydrate gonadal levels only increased during the second experiment at both temperatures and with the three diets. Of the major biochemical components of the adductor muscle, carbohydrate levels changed most during conditioning. Whereas muscle protein levels increased slightly with gonadal maturation, carbohydrate levels dropped considerably. Despite the marked drop in the levels of glycolytic substrates, only the activities of octopine dehydrogenase in the adductor muscle of the scallops conditioned at 16 degrees C consistently decreased. Muscle levels of glycogen phosphorylase were higher in mature than in recently spawned (control) scallops, suggesting a role in the transfer of glucose equivalents from the adductor muscle to other tissues. (C) 2000 Elsevier Science B.V. All rights reserved.