p. 137 - 145 RECHERCHES SUR LA BIOCHIMIE DES PRINCIPALES ESPECES DE MOLLUSQUES BENTHIQUES ET DE POISSONS DU LITORAL ROUMAIN DE LA MER NOIRE Natalia Rosoiu et Maria Panait Institute Roumain de Recherches Marines Constanta Abstract The most important quantitatively invertebrates species Mya arenaria, Mytilus galloprovincialis, Rapana thomasiana, Actinia aequina and fishes species Alosa tanaica nordmanni, Odontogadus merlangus euxinus, Engraulis encrassicholus ponticus and Trachurus mediterraneus ponticus on the Romanian Black Sea coast are the best investigated, too. The marine organisms interact with biotic and abiotic environ- ment: water containing disolved minerals, food and other organisms. The paper emphasizes the biochemical differences versus age, specie population and ecological conditions. The homologous tissues in the fishes belonging to different species present a different biochemical content.