IMPLICATIONS OF STATISTICAL-ANALYSES BASED ON LOCALIZED CHEMICAL CONTENTS ON SOME SPECIES HALIOTIS SHELLS (MOLLUSCA, ARCHAEOGASTROPODA)

Localised chemical analyses of the different layers of the shells in s ome Haliotis species show that biocrysals have distinctive characters. Their chemical contents differ from those of other invertebrate tests , and from those of non biogenic aragonite and calcite. The great vari ability of chemical composition of biogenic aragonites and calcites sh ows that these organisms strongly act upon the mineralization of their shell. The only external parameters do not explain the compositional characteristics of skeletal tissues.