XAFS Studies of Vanadium in the Polychaete Worm Pseudopotamilla Occelata, a New Vanadium Accumulator

High accumulation of vanadium in P. occelata was recently discovered by the authors. The animal is a polychaete worm living in a clean sea and is the second vanadium accumulator in the Animal Kingdom, the ascidians being the first. XAFS analysis of the living animal disclosed that the vanadium was present as V(III) ions in a highly symmetrical octahedral coordination environment. This low oxidation state was stable only in a living state and it was easily oxidized in air to the V(IV) state if the sample was homogenized in an agate mortar or it was dried.