1 NOVEMBER 1999
I. Uriarte, A. Farias-1999
Aquaculture 180: 119-127
Abstract:
This study shows the effect of three different levels of dietary protein content on the performance of postlarvae (1.8 mm) and spat (6.3 mm) of the Chilean scallop, Argopecten purpuratus. The postlarvae showed significant differences in growth and survival, with better growth when fed the high protein diet (N +). The biochemical composition of the postlarvae showed only significant differences in the content of total carbohydrate, with the highest values in postlarvae fed the normal protein diet (N +/-) and the lowest values in starved postlarvae. There were no significant differences in growth nor survival of spat fed the test diets. The biochemical composition of the spat was significantly different in protein content, with the highest level in spat fed the N + diet, while the lipid content increased marginally significantly in spat fed the normal diet. The carbohydrate content in spat did not change. These results show that postlarvae and spat follow a different pattern of energy metabolism, because the diet N + only increased the growth in early postlarval stages and lost its effect in the later stages of development. This paper discusses the threshold age at which the metabolic pathway changes, coinciding with the change from the sessile life attached by the metabolic pathway changes, coinciding with the change from the sessile life attached by the byssus to the typical unattached and free swimming life of A. purpuratus. It also highlights the efficiency and possible use in commercial hatcheries of high protein diets.
(Facultad de Pesquerias y Oceanografia, Universidad Austral de Chile, Casilla 1327, Puerto Montt, Chile)