THE TROPHOSOME OF THE VESTIMENTIFERA RIFTIA-PACHYPTILA AND TEVNIA-JERICHONANA - METAL BIOACCUMULATIONS AND SULFUR METABOLISM

Ultrastructural and microanalytic study of the Vestimentiferan trophos ome shows that the important sulphur quantities present in the organ a re not stored as globules as it was previously hypothesized. We assume that the elemental sulphur could exist under S-8 octaedral structures , whose size is not observable at the microscopic scale inside the bac teria hyaloplasm. Metallic bioaccumulations are not considerable in ba cteria and in bacteriocytes and are due to a physiological purifying m etabolism. Metallic salts, abundant in the hydrothermal fluid, are pro bably poorly soluble and then less toxic than it appeared previously.