p. 129 - 140 COMPARATIVE ASPECTS OF THE DYNAMICS OF THE GENERAL BIOCHEMICAL COMPOSITION IN SOME BIVALVES OF THE ROMANIAN BLACK SEA Adrian Telembici et Gabriela Dimoftache Institut Roumain de Recherches Marines Constanta Abstract The authors present the dynamics of the content of water, mineral substances, total glucides, proteins and lipids throughout a biological year, in Mytillus galloprovincialis Lmk. (rock and deep -water breeds)and Mya arenaria L. The significant variations in the quantity of some biochemical compounds are accounted for by the direct action of the main abiotic and biotic parameters of the environment on the vital activity cycle of the species.