INTRACELLULAR-LOCALIZATION OF VANADIUM IN THE FAN WORM PSEUDOPOTAMILLA-OCCELATA

A very high level of vanadium was found to be contained in the polycha ete worm Pseudopotamilla occelata collected in 1992-1993 from the Sanr iku coast on the main island of Japan. The vanadium concentration (mea n+/-SD=5500+/-1800 mu g g(-1) dry wt) in the worm's branchial crown wh ich is composed of many bipinnate radioles was approximately 100 times higher than that (mean+/-SD=60+/-25 mu g g(-1) dry wt) in the trunk b ody. Electron probe X-ray microanalysis revealed that a large amount o f vanadium was present in the outer potion of the epidermis of the bip innate radiole. Analytical electron microscopy for a cryo-section of t he bipinnate radioles indicated that vanadium was localized in electro n-dense deposits in the epical portion of epidermal cells. From an exa mination of the fine structures, the locality of the electron-dense de posits were found to correspond to that of the apical vacuoles in the epidermal cells. It was concluded that most of the vanadium in P. occe lata was contained in the vacuoles of the epidermal cells of the bipin nate radioles.