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) cul tured at 8, 21 and 34 m in depth in the Golfo de Cariaco, Venezuela, to eva luate the allocation and mobilization of energy in the organisms during per iods of somatic and gonadal growth, and during periods of environmental str ess. A marked decrease in muscle carbohydrates with depth was associated wi th a general decrease in the growth rate of the scallops. Protein in the di gestive gland and carbohydrates in the muscle and remaining tissues dropped during maximal gonadal growth, suggesting that these tissues contributed e nergy for gonadal production. Furthermore, during the reproductive period, scallops at 21 m made greater use of lipids in the digestive gland than ind ividuals at 8 m, probably due to the decreased availability of phytoplankto n at 21 m. During the last 2 months of our study, when scallops that were e nergetically depleted by reproduction were faced with low food availability . high temperatures and colonization by fouling organisms, protein levels i n remaining tissues decreased and lipid levels stabilized. The relative imp ortance of growth and deposition of reserves in somatic tissues was influen ced by reproductive state and prevailing biological and thermal conditions. (C) 2001 Elsevier Science B.V. All rights reserved.