Ultrastructural evidence for iron accumulation within the tube of Vestimentiferan Ridgeia piscesae.

This study reports on the accumulation of iron within the tube wall of the deep sea vent macro invertebrate Vestimentiferan Ridgeia piscesae collected from Juan de Fuca ridge. Combining an array of approaches including environmental scanning electron microscope (ESEM), electron probe micro-analysis (EPMA), X-ray microanalysis (EDS) and transmission electron microscope (TEM), we provide evidences for the influence of prokaryotic organisms on the accumulation of metals on and within the tube wall. Two types of iron-rich minerals such as iron oxides and framboidal pyrites are identified within or on the tube wall. Our results reveal the presence of prokaryotic organism is apparently responsible for the early accumulation of iron-rich minerals in the tube wall. The implications of the biomineralisation of iron in tube wall at hydrothermal vents are discussed.