Radiolarian. Coloured scanning electron micrograph (SEM) of the shell of a radiolarian. Radiolaria are single-celled protozoans that are found in marine plankton. It has a spherical silicate skeleton with pores through which pseudopodia (false feet, not seen) of protoplasm project. As the animal floats in ocean currents the pseudopodia trap food particles on which the radiolarian feeds. This specimen was collected in the Ross Sea, Antarctica. Magnification: x2650 when printed 10cm wide.