Biochemical composition and energy allocation in the tropical scallop Lyropecten ( Nodipecten) nodosus during the months leading up to and following the development of gonads

We quantified biochemical constituents of the major body components of the scallop Lyropecten nodosus (initially measuring 9.4 mm in shell height) cultured at 8, 21 and 34 m in depth in the Golfo de Cariaco, Venezuela, to evaluate the allocation and mobilization of energy in the organisms during periods of somatic and gonadal growth, and during periods of environmental stress. A marked decrease in muscle carbohydrates with depth was associated with a general decrease in the growth rate of the scallops. Protein in the digestive gland and carbohydrates in the muscle and remaining tissues dropped during maximal gonadal growth, suggesting that these tissues contributed energy for gonadal production. Furthermore, during the reproductive period, scallops at 21 m made greater use of lipids in the digestive gland than individuals at 8 m, probably due to the decreased availability of phytoplankton at 21 m. During the last 2 months of our study, when scallops that were energetically depleted by reproduction were faced with low food availability, high temperatures and colonization by fouling organisms, protein levels in remaining tissues decreased and lipid levels stabilized. The relative importance of growth and deposition of reserves in somatic tissues was influenced by reproductive state and prevailing biological and thermal conditions.