Algirosphaera robusta TEM
This very different image was taken with a TEM, and shows the internal structure of a coccolithophore. Two types of heterococcolith cover the cell - some are hood-like (in pink) and others elongated (in green) around the flagellar pole. The interior is dominated by a large chloroplast (in dark green), the light-collecting motor of the cell. Above this sits the nucleus (in pink), which contains the organism's genetic material. In addition, a coccolith in production can be seen inside the cell.
Details: Specimen from the Alboran Sea, western Mediterranean (R/V Hesperides cruise Mater II, station 69). Image courtesy of Ian Probert, Universite de Caen Basse-Normandie, Caen, France.